text:
# How is Anti Aliasing Implemented in Ray Tracing?

After reading a few articles online I can confidently say I am clueless on how Anti-Aliasing works when using Ray Tracing.

All I understand is that A Single Pixel/Ray is split into 4 sub-pixels and 4 rays rather than 1.

Could somebody please explain how this is done (preferably with code)?

I think it's safe to say that there are two different ways of doing AA in raytracing:

1: if you have the final image and the depth image it is possible to apply almost all existing techniques that are used in games (FXAA, etc) Those work directly on the final image and are not related to raytracing

2: the second method is to take into account multiple rays for each pixel and then averaging the result. For a very simple version think of it like this:

• you render first an image of size 1024x1024, one ray for each pixel (for example)
• after rendering, you scale the image to 512x512 (each 4 pixels are avereged into one) and you can notice that the edges are smoother. This way you have effectively used 4 rays for each pixel in the final image of 512x512 size.

There are other variations on this method. For example you can adapt the number of samples for pixels that are right at the edge of the geometry meaning that for some pixels you will have only 4 samples , and for others 16.

Check the links in the comments above.

• So basically I render an image to a large size and when saving it to an image, downscale it to a lower size? That seems quite simple :)! Is this the super sampling method? – Arjan Singh Nov 10 '16 at 14:27
• @Arjan Singh yes it's en.wikipedia.org/wiki/Supersampling , but this is the slowest of them all , raytracing allows you to easily do adaptive supersampling, which can perform a lot better – Raxvan Nov 10 '16 at 14:54

Raxvan is completely right that "traditional" anti aliasing techniques will work in raytracing, including those that use information such as depth to do antialiasing. You could even do temporal anti aliasing in ray tracing for instance.

Julien expanded on Raxvan's 2nd item which was an explanation of super sampling, and showed how you'd actually do that, also mentioning that you can randomize the location of the samples within the pixel but then you are entering signal processing country which is a lot deeper, and it definitely is!

As Julien said, if you want to do $N$ samples per pixel, you can break the pixel up into $N$ evenly distributed sample points (on a grid basically) and average those samples.

If you do that, you can still get aliasing though. It is better than NOT doing it, because you are increasing your sampling rate, so will be able to handle higher frequency data (aka smaller details), but it can still cause aliasing.

If you instead take $N$ random samples within a pixel, you are effectively trading aliasing for noise. Noise is easier on the eyes and looks more natural than aliasing, so is the preferred result usually. I believe it's even provably the ideal situation with higher sample counts but don't have more info on that ):

When you use just "regular" random numbers like you'd get from rand() or std::uniform_int_distribution, that is called "white noise" because it contains all frequencies, like how white light is made up of all other colors (frequencies) of light.

Using white noise to randomize the samples within a pixel has the problem that sometimes your samples will clump together. For instance, if you average 100 samples in a pixel, but they ALL end up being in the upper left corner of the pixel, you aren't going to get ANY information about the other parts of the pixel, so your final resulting pixel color will be missing information about what color it should be.

A better approach is to use something called blue noise which only contains high frequency components (like how blue light is high frequency light).

The benefit of blue noise is that you get even coverage over the pixel, like you get with a uniform sampling grid, but, you still get some randomness, which turns aliasing into noise and gives you a better looking image.

Unfortunately, blue noise can be very costly to compute, and the best methods all seem to be patented (what the heck?!), but one way to do this, invented by pixar (and patented too i think but not 100% sure) is to make an even grid of sample points, then randomly offset each sample point a small amount - like a random amount between plus or minus half the width and height of the sampling grid. This way you get a sort of blue noise sampling for pretty cheap.

Note that this is a form of stratified sampling, and poisson disk sampling is a form of that too, which is also a way of generating blue noise: https://www.jasondavies.com/poisson-disc/

If you are interested in going deeper you probably will also want to check out this question and answer!

What is the fundamental reasoning for anti aliasing using multiple random samples within a pixel?

Lastly, this stuff is starting to stray into the realm of monte carlo path tracing which is the common method for doing photorealistic raytracing. if you are interested in learning more about that, give this a read!

http://blog.demofox.org/2016/09/21/path-tracing-getting-started-with-diffuse-and-emissive/

• As soon as I saw your name, I knew you'd include something on blue noise :) – Hubble Mar 25 at 19:39
• Since this popped up as active again: To explain why this is the case - blue noise sampling patterns excel at integrating functions with most of the energy concentrated in the low frequencies. So by using a blue noise pattern you effectively assume that your signal is mostly smooth/dominated by low frequencies. For high frequency signals, this may actually be counterproductive. Fortunately, natural images have their energy concentrated in the low frequencies. For more details see: sampling.mpi-inf.mpg.de/2019-singh-fourier.html – lightxbulb Mar 26 at 15:39

Let's suppose a fairly typical raytracing main loop:

struct Ray
{
vec3 origin;
vec3 direction;
};

RGBColor* image = CreateImageBuffer(width, height);

for (int j=0; j < height; ++i)
{
for (int i=0; i < width; ++i)
{
float x = 2.0 * (float)i / (float)max(width, height) - 1.0;
float y = 2.0 * (float)j / (float)max(width, height) - 1.0;

vec3 dir = normalize(vec3(x, y, -tanHalfFov));
Ray r = { cameraPosition, dir };

image[width * j + i] = ComputeColor(r);
}
}

One possible modification of it to do 4 samples SSAA would be:

float jitterMatrix[4 * 2] = {
-1.0/4.0,  3.0/4.0,
3.0/4.0,  1.0/3.0,
-3.0/4.0, -1.0/4.0,
1.0/4.0, -3.0/4.0,
};

for (int j=0; j < height; ++i)
{
for (int i=0; i < width; ++i)
{
// Init the pixel to 100% black (no light).
image[width * j + i] = RGBColor(0.0);

// Accumulate light for N samples.
for (int sample = 0; sample < 4; ++sample)
{
float x = 2.0 * (i + jitterMatrix[2*sample]) / (float)max(width, height) - 1.0;
float y = 2.0 * (i + jitterMatrix[2*sample+1]) / (float)max(width, height) - 1.0;

vec3 dir = normalize(vec3(x, y, -tanHalfFov) + jitter);
Ray r = { cameraPosition, dir };

image[width * j + i] += ComputeColor(r);
}

// Get the average.
image[width * j + i] /= 4.0;
}
}

Another possibility is to do a random jitter (instead of the matrix based one above), but you then soon enter the realm of signal processing and it takes a lot of reading to know how to choose a good noise function.

The idea remains the same though: consider the pixel to represent a tiny square area, and instead of shooting only one ray that passes through the center of the pixel, shoot many rays covering the entire pixel area. The more dense the ray distribution is, the better signal you get.

P.S.: I wrote the code above on the fly, so I'd expect a few errors in it. It's only meant to show the basic idea.

• Great Answer! What would be the benefits of using this method opposed to the method @Raxvan used? Will I get the same results by rendering to a large size and then downscaling to a smaller size? – Arjan Singh Nov 10 '16 at 15:28
• Fundamentally, with ray tracing you just don't need to render a bigger image then scale it down. That means you have a lot more flexibility: you can have a lot of samples, you can vary the number of samples depending on the region, and simply, you don't have to add the rescale step. – Julien Guertault Nov 10 '16 at 15:36
• On the topic of jittering, this turns out to be a fairly complex topic. Here is a great paper analyzing the state-of-the-art a few years back graphics.pixar.com/library/MultiJitteredSampling/paper.pdf – Mikkel Gjoel Nov 10 '16 at 15:44
• The code sample above uses a 4 Sample MSAA, if I wanted to do 8x MSAA what would the matrix look like then? What would I need to change in the jitter matrix shown above? – Arjan Singh Dec 3 '16 at 15:59
• @SimonF Thank you for pointing it. Fixed. – Julien Guertault Mar 28 at 17:53

Just to add to the answers above:

Distributed Ray Tracing (Cook, Porter, & Carpenter). Allows you to simultaneously do spatial AA, temporal AA (i.e. motion blur), and focus/depth of field. Best to read the paper, but basically the N-rays you fire per pixel can also be assigned pseudo-random times (for motion blur) and positions on a lens (to get focus effects).

Adaptive Supersampling: You initially fire a certain number of rays per pixel. However, if the rays in a local neighbourhood return significantly different results, then you can locally increase the sampling rate (say 2x), to improve the results. You can opt to repeat the process. It's not perfect since objects can still 'fall between the samples', but it's possibly cheaper than uniformly sampling at a higher rate.

Ray tracing with cones (Amanatides): Instead of using an infinitely thin ray, each ray is instead approximated by a cone, say with a diameter that covers all of the pixel (and a little of the neighbours) allowing you to do evaluate partial coverage. It also has benefits for texture sampling/antialiasing, soft shadows, and potentially LOD of models. I did an implementation many years ago - it's certainly more difficult to do, but does avoid a lot of additional rays. IIRC there was also a scheme called pencil tracing (but my initial search didn't find a link to the paper)


text:
# A photoelectric surface is illuminated successively by monochromatic light of wavelength and  . If the maximum kinetic energy of the emitted photoelectrons in the second case is 3 times that in the first case, the work function of the surface of the material is :(h = Planck's constant, c = speed of light) Option 1) Option 2) Option 3) Option 4)

As discussed in

Conservation of energy -

$h\nu = \phi _{0}+\frac{1}{2}mv^{2}_{max}$

$h\nu = h\nu _{0}+\frac{1}{2}mv^{2}_{max}$

$h\left ( \nu-\nu _{0} \right )=\frac{1}{2}mv^{2}_{max}$

$where, h - Plank's constant\ \nu - Frequency\ \nu_{0} - threshold\ frequency\ \phi_{0}- work function$

- wherein

Let work function be $\phi$

$K_{1}=K.E_{max}=\frac{hc}{\lambda}-\phi \:\:\:\:\:\:\:\:\:\:\:-(i)$

$K_{2}=\frac{hc}{\frac{\pi}{2}}-\phi=2 \frac{hc}{\lambda}-\phi \:\:\:\:\:\:\:\:\:\:\:-(ii)$

According to the question,

$\frac{2hc}{\lambda}-\phi=3 \left( \frac{hc}{\lambda}- \phi \right )$

Or, $\frac{2hc}{\lambda}-\phi=3 \frac{3hc}{\lambda}-3 \phi$

Or, $\frac{2hc}{\lambda}-\phi= \frac{3hc}{\lambda}-3 \phi$

Or, $\phi=\frac{hc}{2\lambda}$

Option 1)

This option is incorrect.

Option 2)

This option is incorrect.

Option 3)

This option is incorrect.

Option 4)

This option is correct.

### Preparation Products

##### Rank Booster NEET 2021

This course will help student to be better prepared and study in the right direction for NEET..

₹ 13999/- ₹ 9999/-
##### Knockout NEET May 2021

An exhaustive E-learning program for the complete preparation of NEET..

₹ 22999/- ₹ 14999/-
##### Knockout NEET May 2022

An exhaustive E-learning program for the complete preparation of NEET..

₹ 34999/- ₹ 24999/-
##### Test Series NEET May 2021

Take chapter-wise, subject-wise and Complete syllabus mock tests and get in depth analysis of your test..

₹ 6999/- ₹ 4999/-

format: plain


text:
Article Contents
Article Contents

# Exponential stability of solutions to impulsive stochastic differential equations driven by $G$-Brownian motion

• In this paper, we establish the $p$-th moment exponential stability and quasi sure exponential stability of the solutions to impulsive stochastic differential equations driven by $G$-Brownian motion (IGSDEs in short) by means of $G$-Lyapunov function method. An example is presented to illustrate the efficiency of the obtained results.
Mathematics Subject Classification: Primary: 34A37, 60H10; Secondary: 34D10.

 Citation:

•  [1] X. Bai and Y. Lin, On the existence and uniqunenss of solutions to the stochastic differential equations driven by $G$-Brownian motion with integral lipschitz codfficients, Acta Math. Appl. Sin. Engl. Ser., 30 (2014), 589-610.doi: 10.1007/s10255-014-0405-9. [2] Z. Chen, Strong laws of large number for capacities, preprint, arXiv:1006.0749. [3] L. Denis, M. Hu and S. Peng, Function spaces and capacity related to a sublinear expectation: application to $G$-Brownian motion pathes, Potential Anal., 34 (2011), 139-161.doi: 10.1007/s11118-010-9185-x. [4] W. Fei and C. Fei, Optimal stochastic control and optimal consumption and portfolio with $G$-Brownian motion, preprint, arXiv:1309.0209. [5] W. Fei and C. Fei, Exponential stability for stochastic differential equations disturbed by $G$-Brownian motion, preprint, arXiv:1311.7311. [6] F. Gao, Pathwise properties and homeomorphic flows for stochastic differential equations driven by $G$-Brownian motion, Stochastic Process. Appl., 119 (2009), 3356-3382.doi: 10.1016/j.spa.2009.05.010. [7] M. Hu and S. Peng, On the representation theorem of $G$-expectations and paths of $G$-Brownian motion, Acta Math. Appl. Sin. Engl. Ser., 25 (2009) 539-546.doi: 10.1007/s10255-008-8831-1. [8] L. Hu, Y. Ren and T. Xu, $p$-moment stability of solutions to stochastic differential equations driven by $G$-Brownian motion, Appl. Math. Comput., 230 (2014), 231-237.doi: 10.1016/j.amc.2013.12.111. [9] V. Lakshmikantham, D. Bainov and P. Simeonov, Theory of Impulsive Differential Equations, World Scientific, Singapore, 1989.doi: 10.1142/0906. [10] X. Li and S. Peng, Stopping times and related Itô's calcilus with $G$-Brownian motion, Stochastic Process. Appl., 121 (2011), 1492-1508.doi: 10.1016/j.spa.2011.03.009. [11] Y. Lin, Stochastic differential equations driven by $G$-Brownian motion with reflecting boundary conditions, Electronic. J. Probbab., 18 (2013), 23pp.doi: 10.1214/EJP.v18-2566. [12] X. Liu, Impulsive stabilization of nonlinear systems, IMA J. Math. Control Inform., 10 (1993), 11-19.doi: 10.1093/imamci/10.1.11. [13] B. Liu, Stability of solutions for stochastic impulsive systems via comparison approach, IEEE Trans. Automat. Control, 53 (2008), 2128-2133.doi: 10.1109/TAC.2008.930185. [14] S. Peng, $G$-expectation, $G$-Brownian motion and related stochastic calculus of Itô type, in Stochastic Analysis and Applications, Abel Symp., 2, Springer, Berlin, 2007, 541-567.doi: 10.1007/978-3-540-70847-6_25. [15] S. Peng, $G$-Brownian motion and dynamic risk measures under volatility uncertainty, preprint, arXiv:0711.2834. [16] S. Peng, Multi-dimensional $G$-Brownian motion and related stochastic calculus under $G$-expectation, Stochastic Process. Appl., 118 (2008), 2223-2253.doi: 10.1016/j.spa.2007.10.015. [17] S. Peng, Nonlinear expectations and stochastic calculus under uncertainty, preprint, arXiv:1002.4546. [18] S. Peng and B. Jia, Some criteria on $p$-th moment stability of impulsive stochastic functional differential equations, Statist. Probab. Lett., 80 (2010), 1085-1092.doi: 10.1016/j.spl.2010.03.002. [19] Y. Ren, Q. Bi and R. Sakthivel, Stochastic functional differential equations with infinite delay driven by $G$-Brownian motion, Math. Methods Appl. Sci., 36 (2013), 1746-1759.doi: 10.1002/mma.2720. [20] Y. Ren and L. Hu, A note on the stochastic differential equations driven by $G$-Brownian motion, Statist. Probab. Lett., 81 (2011), 580-585.doi: 10.1016/j.spl.2011.01.010. [21] L. Shen and J. Sun, $p$-th moment exponential stability of stochastic differential equations with impulsive effect, Sci. China Inf. Sci., 54 (2011), 1702-1711.doi: 10.1007/s11432-011-4250-7. [22] S. Wu, D. Han and X. Meng, $p$-moment stability of stochastic differential equations with jumps, Appl. Math. Comput., 152 (2004), 505-519.doi: 10.1016/S0096-3003(03)00573-3. [23] H. Wu and J. Sun, $p$-moment stability of stochastic differential equations with impulsive jump and Markovian switching, Automatica J. IFAC, 42 (2006), 1753-1759.doi: 10.1016/j.automatica.2006.05.009. [24] X. Wu, L. Yan, W. Zhang and L. Chen, Exponential stability of impulsive stochastic delay differential systems, Discrete Dyn. Nat. Soc., (2012), Art. ID 296136, 15pp.doi: 10.1155/2012/296136. [25] D. Zhang and Z. Chen, Exponential stability for stochastic differential equations driven by $G$-Brownian motion, Appl. Math. Lett., 25 (2012), 1906-1910.doi: 10.1016/j.aml.2012.02.063. [26] B. Zhang, J. Xu and D. Kannan, Extension and application of Itô's formula under $G$-framework, Stochastic Anal. Appl., 28 (2010), 322-349.doi: 10.1080/07362990903546595.


text:
# Interpret GLM model in test of difference in proportions

#### davidecortellino

##### New Member
I'm facing the following situation: We conducted a marketing campaign with three groups: 2 test vs 1 of control, where two different type of coupons sent to the two test groups, 3 euros vs. 6 euros. I understand that the best way to test the difference in proportion is a GLM model with binomial distribution.

The dataset is composed of two columns, one referring to the reference group and the other to the redemption result (1=yes, 0=no). The column "enviados" is just a counter, being "1" for all the observations.
Code:
> head(exp11)
1                    0        1    BONO6EUROS
2                    0        1    BONO6EUROS
3                    0        1    BONO6EUROS
4                    0        1    BONO6EUROS
5                    0        1    BONO6EUROS
6                    0        1    BONO6EUROS
I wanted to test if there was a significant difference in the redemption rate for each group. Here are the rates:

Code:
> head(testexp)
1     benchmark                 1888     9600 0.19666667
2    BONO3EUROS                  113     1316 0.08586626
3    BONO6EUROS                 5449    27227 0.20013222
Indeed there is a difference in proportion redeemed between the different groups ("ratio" column). To test the significance in difference I applied a GLM model, computed the odds ratios, CIs and ran a post-hoc test:

Call:
glm(formula = TRAN_DURING_CAMP_FLG ~ bono_recibido, family = "binomial", data = exp2)

Deviance Residuals:
Min       1Q   Median       3Q      Max
-0.6683  -0.6683  -0.6683  -0.6618   2.2158

Coefficients:
Estimate Std. Error z value Pr(>|z|)
(Intercept)             -1.40726    0.02568 -54.805   <2e-16 ***
bono_recibidoBONO3EUROS -0.95793    0.10166  -9.423   <2e-16 ***
bono_recibidoBONO6EUROS  0.02179    0.02981   0.731    0.465
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

(Dispersion parameter for binomial family taken to be 1)

Null deviance: 37673  on 38142  degrees of freedom
Residual deviance: 37548  on 38140  degrees of freedom
AIC: 37554

Number of Fisher Scoring iterations: 4

> exp(coef(mod.bin)) #odds ratio
(Intercept) bono_recibidoBONO3EUROS bono_recibidoBONO6EUROS
0.2448133               0.3836877               1.0220305
> exp(confint(mod.bin)) # IC
Waiting for profiling to be done...
2.5 %    97.5 %
(Intercept)             0.2327371 0.2573840
bono_recibidoBONO3EUROS 0.3127931 0.4661529
bono_recibidoBONO6EUROS 0.9641824 1.0837123

> summary(glht(mod.bin, mcp(bono_recibido="Tukey")))

Simultaneous Tests for General Linear Hypotheses

Multiple Comparisons of Means: Tukey Contrasts

Fit: glm(formula = cbind(TRAN_DURING_CAMP_FLG, enviados - TRAN_DURING_CAMP_FLG) ~
bono_recibido, family = binomial, data = testexp)

Linear Hypotheses:
Estimate Std. Error z value Pr(>|z|)
BONO3EUROS - benchmark == 0  -0.95793    0.10169  -9.420   <1e-04 ***
BONO6EUROS - benchmark == 0   0.02179    0.02981   0.731    0.728
BONO6EUROS - BONO3EUROS == 0  0.97972    0.09955   9.841   <1e-04 ***
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
(Adjusted p values reported -- single-step method)
I have some doubts about how to interpret the results of the test:

Looking at the GLM model, it seems that the stimulus bono6euro coefficient is not significant, while the stimulus bono3euro and the control group are.

Question: Do I assume that the fact of having received a stimulus of 3 euro significantly impacts the chance of having the customer redeem the coupon? (In this case negatively as the odds ratio of the 3 euro stimulus is less than the one of the intercept: 0.2448133*0.3836877=0.0939) while the fact of having received a stimulus of 6 euro does not significantly affect the odds ratio relative to not having received any kind of stimulus?
Looking at the deviances, the residual deviance is slightly lower than the null deviance. I understand it means that the model does not explain much of the variability in the dataset (lower than 1%).

Question: Can I assume correctly that the fact of having received the stimulus have a low explanatory power of the redemption behaviour in the sample? Which means that the fact of having received one of the two stimuli has not triggered in the test groups any greater spending behaviour than the control group, meaning the stimuli have not worked properly?
The confidence intervals for the odds ratios do not include "0" and are narrow.

Question: Can I assume that the odds ratio are then precise enough in telling me that, being <1, the exposure to the stimulus is associated with lower odds of stimulating a purchasing behaviour in the sample? Which means, again, that the stimulus used have not affected the consumer behaviour?

#### consuli

##### Member
Maybe your post will become more clear, if you

1. st present the experiment and your working hyptheses,
2. nd present present the data
3. rd present the model building y ~ x1 + x2 +x ...
4. th present the model results like summary() ...


text:
# Posts Tagged proton

## Recent Postings from proton

### Evidence for polarization of gluons in the proton

We discuss the impact of recent high-statistics RHIC data on the determination of the gluon polarization in the proton in the context of a global QCD analysis of polarized parton distributions. We find clear evidence for a non-vanishing polarization of gluons in the region of momentum fraction and at the scales mostly probed by the data. Although information from low momentum fractions is presently lacking, this finding is suggestive of a significant contribution of gluon spin to the proton spin, thereby limiting the amount of orbital angular momentum required to balance the proton spin budget.

### A determination of the parton distributions for flavor asymmetric light sea in the proton

Using the DGLAP equation with corrections of parton recombination, it is the first time that the distributions of the flavor asymmetric sea in the proton are extracted from the available experimental data in a model-independent way. We find that the distribution shape of the asymmetric sea quark is similar to that of the corresponding valence quark. Based on the separation of the flavor symmetric and asymmetric sea, the possible relations between the strange quark distribution and symmetric light quark distribution in the proton are discussed. The results are used to explain the recent HERMES results for the strange quark distribution. The comparisons of our results with the predictions of the CTEQ-, MRS-, GRV- databases and some models for flavor asymmetric sea are also presented.

### Upper critical field and absence of superconductivity in magnetars

We study the upper critical field for quenching of the proton superconductivity in neutron stars, $H_{c2}$, within a Ginzburg-Landau theory which includes the entrainment between the proton and neutron condensates. We construct models of compact stars for a (realistic) nucleonic equations of state and deduce the volume occupied by the superconducting regions from microscopic calculations of proton pairing gaps in dense matter. We argue that magnetars with surface fields $B \ge 10^{15}$ G are either partially or completely non-superconducting, the precise outcome being dependent on the relation between the surface dipolar field and the field intensity at the crust-core boundary. We discuss the implications of the absence of superconductivity in magnetars on their cooling evolution and superfluid dynamics.

### Higgsstrahlung at forward rapidities

We discuss the inclusive and single diffractive heavy flavor (top and bottom) production in association with the Higgs boson at forward rapidities in proton-proton collisions at the LHC. The calculations are performed in the framework of the phenomenological dipole approach, which automatically accounts for the absorptive corrections induced by soft interactions, i.e. for the gap survival effects at the amplitude level. Major differential observables including the realistic ATLAS detector constraints are considered. The forward inclusive and diffractive Higgsstrahlung processes are generated essentially by excitation of the valence or sea quarks in the proton. The single diffractive Higgsstrahlung off top quarks is found to dominate compared to the loop-induced mechanism at sufficiently large Higgs boson transverse momenta. The Higgsstrahlung processes offer a direct and precise measurement of Higgs-top and, possibly, Higgs-bottom Yukawa couplings at the LHC, as well as the studies of the intrinsic heavy flavor components of the proton.

### Phenomenology of kt-factorization for inclusive Higgs boson production at LHC

We investigate the inclusive Higgs boson production in proton-proton collisions at high energies in the framework of kt-factorization QCD approach. The attention is focused on the dominant off-shell gluon-gluon fusion subprocess, where the transverse momentum of incoming gluons are taken into account. The transverse momentum dependent (or unintegrated) gluon densities of the proton are determined using the CCFM evolution equation as well as the Kimber-Martin-Ryskin prescription. We study the theoretical uncertainties of our calculations and perform the comparison with the results of traditional pQCD evaluations. Our predictions agree well with the first experimental data taken by the ATLAS collaboration at the LHC. We argue that further studies of the Higgs boson production are capable of constraining the unintegrated gluon densities of the proton.

### Drell-Yan lepton pair production at LHC and TMD quark densities of the proton

We use the TMD quark densities of the proton to investigate unpolarized Drell-Yan lepton pair production in proton-proton collisions at the LHC energies. We investigate the case where the gluon-to-quark splitting occurs at the last evolution step and calculate the TMD sea quark density as a convolution of the CCFM-evolved gluon distribution and the TMD gluon-to-quark splitting function which contains all single logarithmic small-x corrections to the sea quark evolution for any order of perturbation theory. Based on the O(alpha) production amplitude of quark-antiquark annihilation calculated according to the reggeized quark approach, we analyze the distributions on the dilepton invariant mass, transverse momentum and rapidity as well as the specific angular correlations between the produced leptons as measured by the CMS, ATLAS and LHCb collaborations. We argue that these measurements impose stringent constraints on the TMD quark distributions of the proton.

### Drell-Yan lepton pair production at LHC and TMD quark densities of the proton [Replacement]

We use the TMD quark densities of the proton to investigate unpolarized Drell-Yan lepton pair production in proton-proton collisions at the LHC energies. We investigate the case where the gluon-to-quark splitting occurs at the last evolution step and calculate the TMD sea quark density as a convolution of the CCFM-evolved gluon distribution and the TMD gluon-to-quark splitting function which contains all single logarithmic small-x corrections to the sea quark evolution for any order of perturbation theory. Based on the O(alpha) production amplitude of quark-antiquark annihilation calculated according to the reggeized quark approach, we analyze the distributions on the dilepton invariant mass, transverse momentum and rapidity as well as the specific angular correlations between the produced leptons as measured by the CMS, ATLAS and LHCb collaborations. We argue that these measurements impose stringent constraints on the TMD quark distributions of the proton.

### Shadowing in multiparton proton - deuteron collisions

We study the screening effect for the multiparton interactions (MPI) for proton–deuteron collisions in the kinematics where one parton belonging to the deuteron has small $x_1$ so the leading twist shadowing is present while the second parton ($x_2$) is involved in the interaction where shadowing effects are small. We find that the ratio of the shadowing and the impulse approximation terms is approximately factor of two larger for MPI than for the single parton distributions. Overall shadowing leads to a strong reduction of the double parton antishadowing effect due to the independent interactions of the partons of the protons with two nucleons of the deuteron. For example, for the resolution scale $Q_1^2 \sim 4 \mbox{GeV}^2$ of the interaction with parton $x_1$ we find that shadowing reduces the DPA effect by $\sim$ 30 %.

### Saturation effects in forward-forward dijet production in p+Pb collisions

We study saturation effects in the production of forward dijets in proton-lead collisions at the Large Hadron Collider, using the framework of High Energy Factorization. Such configurations, with both jets produced in the forward direction, probe the gluon density of the lead nucleus at small longitudinal momentum fraction, and also limit the phase space for emissions of additional jets. We find significant suppression of the forward dijet azimuthal correlations in proton-lead versus proton-proton collisions, which we attribute to stronger saturation of the gluon density in the nucleus than in the proton. In order to minimize model dependence of our predictions, we use two different extensions of the Balitsky-Kovchegov equation for evolution of the gluon density with sub-leading corrections.

### Coulomb corrections to electron scattering on the extended source and the proton charge radius

It is shown that the account for the proton charge form factor in the Coulomb corrections to the electron-proton scattering cross section noticeably diminishes the difference between the value of the proton charge radius $r_{\mathrm{E}}$, extracted from the $ep$ scattering data, and that following from the muonic hydrogen data. For the electron energy much higher than the electron mass but much smaller than $r_{\mathrm{E}}^{-1}\approx 230$~MeV, the relative correction has the universal form $\delta r_{\mathrm{E}}/r_{\mathrm{E}}=-\pi\alpha/2$, where $\alpha$ is the fine structure constant.

### On the relation between the spin and the magnetic moment of the proton

In the context of the quark model of hadrons the spin and the magnetic moment of proton can not be taken proportional. This is in contradiction with the widely used relation between these two properties of the proton. This apparent difficulty is addressed by the most elementary notions of the relevant physics. In particular it is emphasized that the widely used relation is only valid in the lowest orders of perturbation, in which transitions between different baryons do not occur. For other processes where such transitions do occur, such as inelastic scattering off the protons, the quark model relation for the magnetic moment is used to give an estimation for the amplitude of transition between states with different total spins.

### Nuclear parton density modifications from low-mass lepton pair production at the LHC

In this article, we investigate the potential of low-mass lepton pair production in proton-ion collisions at the LHC to constrain nuclear modifications of parton densities. Similarly to prompt photon production, the transverse momentum spectrum is shown to be dominated by the QCD Compton process, but has virtually no fragmentation or isolation uncertainties. Depending on the orientation of the proton and ion beams and on the use of central or forward detector components, all interesting regions of nuclear effects (shadowing, antishadowing, isospin and EMC effects) can be probed. Ratios of cross sections allow to eliminate theoretical scale and bare-proton parton density errors as well as many experimental systematic uncertainties.

### Marrying ab initio calculations and Halo EFT: the case of ${}^7{\rm Be} + p \rightarrow {}^8{\rm B} + \gamma$ [Cross-Listing]

We report a leading-order (LO) calculation of $^7\mathrm{Be}(p,\gamma)^8\mathrm{B}$ in a low-energy effective field theory. $^8\mathrm{B}$ is treated as a shallow proton$+^7\mathrm{Be}$ core and proton$+^7\mathrm{Be}^{*}$ (core excitation) $p$-wave bound state. The couplings are fixed using measured binding energies and proton-$^7\mathrm{Be}$ $s$-wave scattering lengths, together with $^8\mathrm{B}$ asymptotic normalization coefficients from ab initio calculations. We obtain a zero-energy $S$-factor of $18.2 \pm 1.2~({\rm ANC~only})$ eV b. Given that this is a LO result it is consistent with the recommended value $S(0)=20.8\pm1.6$ eV b. Our computed $S(E)$ compares favorably with experimental data on $^7\mathrm{Be}(p,\gamma)^8\mathrm{B}$ for $E <0.4$ MeV. We emphasize the important role of proton-$^7\mathrm{Be}$ scattering parameters in determining the energy dependence of $S(E)$, and demonstrate that their present uncertainties significantly limit attempts to extrapolate these data to stellar energies.

### Hadronic Gamma-Ray and Neutrino Emission from Cygnus X-3

Cygnus X-3 (Cyg X-3) is a remarkable Galactic microquasar (X-ray binary) emitting from radio to $\gamma$-ray energies. In this paper, we consider hadronic model of emission of $\gamma$-rays above 100 MeV and their implications. We focus here on the joint $\gamma$-ray and neutrino production resulting from proton-proton interactions within the binary system. We find that the required proton injection kinetic power, necessary to explain the $\gamma$-ray flux observed by AGILE and Fermi-LAT, is $L_p \sim 10^{38}\:\rm{erg\:s^{-1}}$, a value in agreement with the average bolometric luminosity of the hypersoft state (when Cygnus X-3 was repeatedly observed to produce transient $\gamma$-ray activity). If we assume an increase of the wind density at the superior conjunction, the asymmetric production of $\gamma$-rays along the orbit can reproduce the observed modulation. According to observational constraints and our modelling, a maximal flux of high-energy neutrinos would be produced for an initial proton distribution with a power-law index $\alpha=2.4$. The predicted neutrino flux is almost two orders of magnitude less than the 2-month IceCube sensitivity at $\sim$1 TeV. If the protons are accelerated up to PeV energies, the predicted neutrino flux for a prolonged "soft X-ray state" would be a factor of about 3 lower than the 1-year IceCube sensitivity at $\sim$10 TeV. This study shows that, for a prolonged soft state (as observed in 2006) possibly related with $\gamma$-ray activity and a hard distribution of injected protons, Cygnus X-3 might be close to being detectable by cubic-kilometer neutrino telescopes such as IceCube.

### The Environment around the Young Massive Star Cluster RSGC 1 and HESS J1837-069

We report on Mopra observations toward the young massive star cluster RSGC 1, adjoined by, and possibly associated with the gamma-ray source HESS J1837-069. We measure the CO (J=1-0) distribution around the cluster and gamma-ray source, and find that the cluster is slightly higher than the velocity ranges associated with the Crux-Scutum arm. We reveal the cluster is associated with much less molecular gas compared with other young massive clusters in the Galaxy, Westerlund 1 (Wd 1) and 2 (Wd 2), which also radiate gamma-rays. We find no other structures that would otherwise indicate the action of supernova remnants, and due to the lack of material which may form gamma-rays by hadronic interaction, we conclude that the gamma-rays detected from HESS J1837-069 are not created through proton-proton interactions, and may more plausibly originate from the pulsar that was recently found near RSGC 1.

### Supernova neutrinos and nucleosynthesis

Observations of metal-poor stars indicate that at least two different nucleosynthesis sites contribute to the production of r-process elements. One site is responsible for the production of light r-process elements Z<~50 while the other produces the heavy r-process elements. We have analyzed recent observations of metal-poor stars selecting only stars that are enriched in light r-process elements and poor in heavy r-process elements. We find a strong correlation between the observed abundances of the N=50 elements (Sr, Y and Zr) and Fe. It suggest that neutrino-driven winds from core-collapse supernova are the main site for the production of these elements. We explore this possibility by performing nucleosynthesis calculations based on long term Boltzmann neutrino transport simulations. They are based on an Equation of State that reproduces recent constrains on the nuclear symmetry energy. We predict that the early ejecta is neutron-rich with Ye ~ 0.48, it becomes proton rich around 4 s and reaches Ye = 0.586 at 9 s when our simulation stops. The nucleosynthesis in this model produces elements between Zn and Mo, including 92Mo. The elemental abundances are consistent with the observations of the metal-poor star HD 12263. For the elements between Ge and Mo, we produce mainly the neutron-deficient isotopes. This prediction can be confirmed by observations of isotopic abundances in metal-poor stars. No elements heavier than Mo (Z=42) and no heavy r-process elements are produced in our calculations.

### Limits on Alpha Particle Temperature Anisotropy and Differential Flow from Kinetic Instabilities: Solar Wind Observations [Replacement]

Previous studies have shown that the observed temperature anisotropies of protons and alpha particles in the solar wind are constrained by theoretical thresholds for pressure-anisotropy-driven instabilities such as the Alfv\’en/ion-cyclotron (A/IC) and fast-magnetosonic/whistler (FM/W) instabilities. In this letter, we use a long period of in-situ measurements provided by the {\em Wind} spacecraft’s Faraday cups to investigate the combined constraint on the alpha-proton differential flow velocity and the alpha-particle temperature anisotropy due to A/IC and FM/W instabilities. We show that the majority of the data are constrained to lie within the region of parameter space in which A/IC and FM/W waves are either stable or have extremely low growth rates. In the minority of observed cases in which the growth rate of the A/IC (FM/W) instability is comparatively large, we find relatively higher values of $T_{\perp\alpha}/T_{\perp p}$ ($T_{\parallel\alpha}/T_{\parallel p}$) when alpha-proton differential flow velocity is small, where $T_{\perp\alpha}$ and $T_{\perp p}$ ($T_{\parallel\alpha}$ and $T_{\parallel p}$) are the perpendicular (parallel) temperatures of alpha particles and protons. We conjecture that this observed feature might arise from preferential alpha-particle heating which can drive the alpha particles beyond the instability thresholds.

### Limits on Alpha Particle Temperature Anisotropy and Differential Flow from Kinetic Instabilities: Solar Wind Observations

Previous studies have shown that the observed temperature anisotropies of protons and alpha particles in the solar wind are constrained by theoretical thresholds for pressure-anisotropy-driven instabilities such as the Alfv\’en/ion-cyclotron (A/IC) and fast-magnetosonic/whistler (FM/W) instabilities. In this letter, we use a long period of in-situ measurements provided by the {\em Wind} spacecraft’s Faraday cups to investigate the combined constraint on the alpha-proton differential flow velocity and the alpha-particle temperature anisotropy due to A/IC and FM/W instabilities. We show that the majority of the data are constrained to lie within the region of parameter space in which A/IC and FM/W waves are either stable or have extremely low growth rates. In the minority of observed cases in which the growth rate of the A/IC (FM/W) instability is comparatively large, we find relatively higher values of $T_{\perp\alpha}/T_{\perp p}$ ($T_{\parallel\alpha}/T_{\parallel p}$) when alpha-proton differential flow velocity is small, where $T_{\perp\alpha}$ and $T_{\perp p}$ ($T_{\parallel\alpha}$ and $T_{\parallel p}$) are the perpendicular (parallel) temperatures of alpha particles and protons. We conjecture that this observed feature might arise from preferential alpha-particle heating which can drive the alpha particles beyond the instability thresholds.

### Investigating of longitudinal development parameters through air shower simulation by different hadronic models

In this work the simulation of the Extensive Air Showers was performed by investigating the longitudinal development parameters (N and Xmax) by using a system for air shower simulation which is called AIRES version 2.6.0 at the energy range (10^14-10^19 eV) for different primary particles like (gamma, electron, positron, proton and iron nuclei) and different zenith angles. The comparison of simulated longitudinal profile was fulfilled for different hadronic models (SIBYLL, QGSJET99 and SIBYLL S16).

### Symmetry energy, unstable nuclei, and neutron star crusts [Cross-Listing]

Phenomenological approach to inhomogeneous nuclear matter is useful to describe fundamental properties of atomic nuclei and neutron star crusts in terms of the equation of state of uniform nuclear matter. We review a series of researches that we have developed by following this approach. We start with more than 200 equations of state that are consistent with empirical masses and charge radii of stable nuclei and then apply them to describe matter radii and masses of unstable nuclei, proton elastic scattering and total reaction cross sections off unstable nuclei, and nuclei in neutron star crusts including nuclear pasta. We finally discuss the possibility of constraining the density dependence of the symmetry energy from experiments on unstable nuclei and even observations of quasi-periodic oscillations in giant flares of soft gamma-ray repeaters.

### Particle acceleration and dynamics of double-double radio galaxies: theory vs. observations

In this paper we show that a small sample of radio galaxies with evidence for multiple epochs of jet activity (so-called double-double’ radio galaxies) have the same electron injection spectral index in the two activity episodes, a result which might be considered surprising given the very different lobe dynamics expected in the first and second episode. We construct models for the dynamics of radio galaxies, with an emphasis on their episodic behaviour, and show that hotspot formation and confinement of lobes for the inner double of double-double radio galaxies are possible even without any thermal matter in the outer cocoon. We argue that (i) the observed similar injection spectral indices are due to similar jet powers in the two episodes, (ii) the spectral index–radio power’ correlation of a flux limited sample of radio galaxies is the primary one, and not the spectral index–redshift correlation’, (iii) jets are made of pair plasma and not electron-proton, (iv) and the Lorentz factor of the spine of the jet should be $\gapp 10$ to explain the observations. Furthermore, we argue that the observations show that higher power radio galaxies do not have a higher jet bulk Lorentz factors, but instead simply have a higher number density of particles in the jet rest frame. A consequence of our models is that aligned double-double radio galaxies with very old ($\gapp10^8$ yr) outer doubles, or misaligned double-double radio galaxies, are statistically more likely to have dissimilar injection indices in two different episodes, as they will probably have different jet powers.

### Measurements of cosmic rays at the highest energies with the Pierre Auger Observatory

This paper summarizes the status and the recent measurements from the Pierre Auger Observatory. The energy spectrum is described and its features discussed. We report searches for anisotropy of cosmic ray arrival directions on large scales and through correlation with catalogues of celestial objects. We also present the search for anisotropies in the data without the use of astronomical catalogues. The first measurement of the proton-air cross section around 10^{18} eV is discussed. Finally, the mass composition is addressed with measurements of the variation of the depth of shower maximum with energy and with the muon density at ground.

### Constraints on the source of ultra-high energy cosmic rays using anisotropy vs chemical composition

The joint analysis of anisotropy signals and chemical composition of ultra-high energy cosmic rays offers strong potential for shedding light on the sources of these particles. Following up on an earlier idea, this paper studies the anisotropies produced by protons of energy >E/Z, assuming that anisotropies at energy >E have been produced by nuclei of charge Z, which share the same magnetic rigidity. We calculate the number of secondary protons produced through photodisintegration of the primary heavy nuclei. Making the extreme assumption that the source does not inject any proton, we find that the source(s) responsible for anisotropies such as reported by the Pierre Auger Observatory should lie closer than ~20-30, 80-100 and 180-200 Mpc if the anisotropy signal is mainly composed of oxygen, silicon and iron nuclei respectively. A violation of this constraint would otherwise result in the secondary protons forming a more significant anisotropy signal at lower energies. Even if the source were located closer than this distance, it would require an extraordinary metallicity >120, 1600, 1100 times solar metallicity in the acceleration zone of the source, for oxygen, silicon and iron respectively, to ensure that the concomitantly injected protons not to produce a more significant low energy anisotropy. This offers interesting prospects for constraining the nature and the source of ultra-high energy cosmic rays with the increase in statistics expected from next generation detectors.

### Isospin dependence of entrainment in superfluid neutron stars in a relativistic model

We study the entrainment effect between superfluid neutrons and charge neutral fluid (called the proton fluid) which is made of protons and electrons in neutron star interior in a relativistic model where baryon-baryon interaction is mediated by the exchange of $\sigma$, $\omega$ and $\rho$ mesons. This model also includes scalar self interactions. The entrainment matrix and entrainment parameter are calculated using the parameter set of Glendenning (GL). The inclusion of $\rho$ meson strongly influences the entrainment parameter ($\epsilon_{mom}$) in a superfluid neutron star. It is constant at the core and drops to the surface. The entrainment parameter takes values within the physical range.

### A variable absorption feature in the X-ray spectrum of a magnetar

Soft gamma-ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs) are slowly rotating, isolated neutron stars that sporadically undergo episodes of long-term flux enhancement (outbursts) generally accompanied by the emission of short bursts of hard X-rays. This behaviour can be understood in the magnetar model, according to which these sources are mainly powered by their own magnetic energy. This is supported by the fact that the magnetic fields inferred from several observed properties of AXPs and SGRs are greater than – or at the high end of the range of – those of radio pulsars. In the peculiar case of SGR 0418+5729, a weak dipole magnetic moment is derived from its timing parameters, whereas a strong field has been proposed to reside in the stellar interior and in multipole components on the surface. Here we show that the X-ray spectrum of SGR 0418+5729 has an absorption line, the properties of which depend strongly on the star’s rotational phase. This line is interpreted as a proton cyclotron feature and its energy implies a magnetic field ranging from 2E14 gauss to more than 1E15 gauss.

### UHECR correlations taking account of composition and Galactic magnetic deflections

We predict the arrival direction distribution of cosmic rays including their deflection in the Galactic magnetic field, for several combinations of source and composition hypotheses: the sources are hard X-ray AGNs or uniformly sample the matter distribution of galaxies, and the composition at the source is pure proton or is the Galactic cosmic ray composition measured by CREAM. We use the regular component of the Jansson-Farrar 2012 model for the GMF and allow for rigidities as low as 2 EeV. We report the correlations of published UHECRs, rescaling event energies so as to reconcile the spectra of the different experiments and taking the overall energy uncertainty into account; different composition hypotheses are considered. This work demonstrates the feasibility of calculating GMF deflections to low enough rigidities to allow for heavy composition in correlation studies, and that non-trivial arrival direction structure should be expected even for mixed or heavy composition, as long as UHECRs come from the local universe.

### The Chemical Composition of Praesepe (M44)

Star clusters have long been used to illuminate both stellar evolution and Galactic evolution. They also hold clues to the chemical and nucleosynthetic processes throughout the history of the Galaxy. We have taken high signal-to-noise, high-resolution spectra of 11 solar-type stars in the Praesepe open cluster to determine the chemical abundances of 16 elements: Li, C, O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Fe, Ni, Y, and Ba. We have determined Fe from Fe I and Fe II lines and find [Fe/H] = +0.12 $\pm$0.04. We find that Li decreases with temperature due to increasing Li depletion in cooler stars; it matches the Li-temperature pattern found in the Hyades. The [C/Fe] and [O/Fe] abundances are below solar and lower than the field star samples due to the younger age of Praesepe (0.7 Gyr) than the field stars. The alpha-elements, Mg, Si, Ca, and Ti, have solar ratios with respect to Fe, and are also lower than the field star samples. The Fe-peak elements, Cr and Ni, track Fe and have solar values. The neutron capture element [Y/Fe] is found to be solar, but [Ba/Fe] is enhanced relative to solar and to the field stars. Three Praesepe giants were studied by Carrera and Pancino; they are apparently enhanced in Na, Mg, and Ba relative to the Praesepe dwarfs. The Na enhancement may indicate proton-capture nucleosynthesis in the Ne -> Na cycling with dredge-up into the atmospheres of the red giants.

### Measurements of Charge Transfer Efficiency in a Proton-irradiated Swept Charge Device

Charge Coupled Devices (CCDs) have been successfully used in several low energy X-ray astronomical satellite over the past two decades. Their high energy resolution and high spatial resolution make them an perfect tool for low energy astronomy, such as formation of galaxy clusters and environment of black holes. The Low Energy X-ray Telescope (LE) group is developing Swept Charge Device (SCD) for the Hard X-ray Modulation Telescope (HXMT) satellite. SCD is a special low energy X-ray CCD, which could be read out a thousand times faster than traditional CCDs, simultaneously keeping excellent energy resolution. A test method for measuring the charge transfer efficiency (CTE) of a prototype SCD has been set up. Studies of the charge transfer inefficiency (CTI) have been performed at a temperature range of operation, with a proton-irradiated SCD.

### AD 775 Pulse of Cosmogenic Radionuclides Production as Imprint of a Galactic Gamma-Ray Burst

We suggest an explanation of a sharp increase in the abundance of cosmogenic radiocarbon found in tree rings dated AD 775. The increase could originate from high-energy irradiation of the atmosphere by a galactic gamma-ray burst. We argue that, unlike a cosmic ray event, a gamma-ray burst does not necessarily result in a substantial increase in long-lived 10Be atmospheric production. At the same time, the 36Cl nuclide would be generated in the amounts detectable in the corresponding ice core samples from Greenland and Antarctica. These peculiar features allow experimental discrimination of nuclide effects caused by gamma-ray bursts and by powerful proton events.

### Mass sensitivity in the radio lateral distribution function

Measuring the mass composition of ultra-high energy cosmic rays is one of the main tasks in the cosmic rays field. Here we are exploring the composition signature in the coherent electromagnetic emission from extensive air showers, detected in the MHz frequency range. One of the experiments that successfully detects radio events in the frequency band of 40-80 MHz is the LOPES experiment at KIT. It is a digital interferometric antenna array and has the important advantage of taking data in coincidence with the particle detector array KASCADE-Grande. A possible method to look at the composition signature in the radio data, predicted by simulations, concerns the radio lateral distribution function, since its slope is strongly correlated with Xmax. Recent comparison between REAS3 simulations and LOPES data showed a significantly improved agreement in the lateral distribution function and for this reason an analysis on a possible LOPES mass signature through the slope method is promising. Trying to reproduce a realistic case, proton and iron showers are simulated with REAS3 using the LOPES selection information as input parameters. The obtained radio lateral distribution slope is analyzed in detail. The lateral slope method to look at the composition signature in the radio data is shown here and a possible signature of mass composition in the LOPES data is discussed.

### Detecting Local Deflection Patterns of Ultra-high Energy Cosmic Rays using the Principal Axes of the Directional Energy Distribution

From deflections in galactic and extragalactic magnetic fields energy dependent structures in the arrival directions of ultra-high energy cosmic rays (UHECR) are expected. We propose to characterize these structures by the strength of collimation of energy along the principal axes in selected regions in the sky. While the strength of collimation are indicators of anisotropy in the arrival distribution of UHECR, the orientation of the principal system holds information about the direction of the deflections of UHECR. We discuss the method and present expected limits on the strength of deflection and density of sources using simulated scenarios of UHECR proton propagation.

### Goldstone modes in the neutron star core [Cross-Listing]

We formulate a theory of Goldstone bosons and their interactions in the superfluid and superconducting phase of dense nucleonic matter at densities of relevance to the neutron star core. For typical neutron star temperatures in the range T = 10^6 to 10^9 K, the Goldstone mode associated with rotational symmetry, called angulons, couple weakly to each other and to electrons. Consequently, these modes have anomalously large mean free paths and can contribute to both diffusive and ballistic transport of heat and momentum. In contrast, the two Goldstone bosons associated with density oscillations of the neutron and electron + proton fluids, called superfluid phonons, mix and couple strongly to electrons. They have shorter mean free paths, and their contribution to transport is negligible. Long-wavelength superfluid phonons and angulons can play a role in neutron star seismology, and lead to interesting phenomenology as angulons couple to magnetic fields and have anisotropic dispersion relations.

### Stochastic Heating, Differential Flow, and the Alpha-to-Proton Temperature Ratio in the Solar Wind

We extend previous theories of stochastic ion heating to account for the motion of ions along the magnetic field. We derive an analytic expression for the ion-to-proton perpendicular temperature ratio in the solar wind for any ion species, assuming that stochastic heating is the dominant ion heating mechanism. This expression describes how this temperature ratio depends upon the average velocity of the ions along the magnetic field direction and the ratio of the parallel proton pressure to the magnetic pressure. We compare our model with previously published measurements of alpha particles and protons from the WIND spacecraft. We find that stochastic heating offers a promising explanation for these measurements when the fractional cross helicity and Alfven ratio at the proton-gyroradius scale have values that are broadly consistent with solar-wind measurements.

### Testing models of new physics with UHE air shower observations

Several air shower observatories have established that the number of muons produced in UHE air showers is significantly larger than that predicted by models. We argue that the only solution to this muon deficit, compatible with the observed Xmax distributions, is to reduce the transfer of energy from the hadronic shower into the EM shower, by reducing the production or decay of pi0s. We present four different models of new physics, each with a theoretical rationale, which can accomplish this. One has a pure proton composition and three have mixed composition. Two entail new particle physics and suppress pi0 production or decay above LHC energies. The other two are less radical but nonetheless require significant modifications to existing hadron production models — in one the changes are only above LHC energies and in the other the changes extend to much lower energies. We show that the models have distinctively different predictions for the correlation between the number of muons at ground and Xmax in hybrid events, so that with future hybrid data it should be possible to discriminate between models of new physics and disentangle the particle physics from composition.

### Rapidity and momentum transfer distributions of coherent $J/\psi$ photoproduction in ultraperipheral pPb collisions at the LHC [Replacement]

Based on accurate calculations of the flux of equivalent photons of the proton and heavy nuclei and the pQCD framework for the gluon distribution in the proton and nuclei, we analyze the rapidity and momentum transfer distributions of coherent $J/\psi$ photoproduction in ultraperipheral proton-Pb collisions at the LHC. We demonstrate that unlike the case of proton-proton UPCs marred by certain theoretical uncertainties and experimental limitations, after a cut excluding the region of small momentum transfers, ultraperipheral proton-Pb collisions offer a clean way to study the gluon distribution in the proton down to $x \approx 10^{-5}$. Our analysis of the momentum transfer distributions shows that an interplay of $J/\psi$ production by low-energy photons on the nucleus and by high-energy photons on the proton in proton-Pb UPCs can result in some excess of events at small $p_t$ in a definite region of the rapidity y.

### Constraints on asymmetric dark matter from asteroseismology [Replacement]

We report recent results on the impact of asymmetric dark matter (DM) particles on low-mass stars. First, we found that the small convective core expected in stars with masses between 1.1 and 1.3 Msun is suppressed due to DM cooling. Moreover, stars with masses below 1 Msun have their central temperatures and densities more strongly influenced by DM than in the solar case. We were able to put limits to the DM mass and spin-dependent DM-proton scattering cross section by comparing the modelling of the nearby star Alpha Cen B with photometric, spectroscopic and asteroseismic observations.

### Constraints on asymmetric dark matter from asteroseismology

We report recent results on the impact of asymmetric dark matter (DM) particles on low-mass stars. First, we found that the small convective core expected in stars with masses between 1.1 and 1.3 Msun is suppressed due to DM cooling. Moreover, stars with masses below 1 Msun have their central temperatures and densities more strongly influenced by DM than in the solar case. We were able to put limits to the DM mass and spin-dependent DM-proton scattering cross section by comparing the modelling of the nearby star Alpha Cen B with photometric, spectroscopic and asteroseismic observations.

### Geomagnetic Backtracing: A comparison of Tsyganenko 1996 and 2005 External Field models with AMS-02 data

We used a backtracing code to reconstruct particle trajectory inside the Earth Magnetosphere during the last solar active period (2011 and 2012) when very high Solar Wind pressure values were measured. We compared our results on AMS-02 proton and electron data with 2 different External Field models, namely Tsyganenko 1996 (T96) and 2005 (T05), both for quiet (defined as the periods when the solar wind pressure is below the average value, set at 2nPa) and active periods. Although T05 has been specifically designed for storm events, at high energy the particle trajectory is similar for the two models. For instance at rigidities larger than 50 GV, the RMS of angular difference between reconstructed asymptotic direction outside the Magnetosphere is of the order of the millirad, while it increases at intermediate energies. We also confirmed, as a function of the pointing direction, the well known East-West effect on the trajectory of primary particles and on the access solid angle on the AMS detector.

### NGC 362: another globular cluster with a split red giant branch

We obtained FLAMES GIRAFFE+UVES spectra for both first and second-generation red giant branch (RGB) stars in the globular cluster (GC) NGC 362 and used them to derive abundances of 21 atomic species for a sample of 92 stars. The surveyed elements include proton-capture (O, Na, Mg, Al, Si), alpha-capture (Ca, Ti), Fe-peak (Sc, V, Mn, Co, Ni, Cu), and neutron-capture elements (Y, Zr, Ba, La, Ce, Nd, Eu, Dy). The analysis is fully consistent with that presented for twenty GCs in previous papers of this series. Stars in NGC 362 seem to be clustered into two discrete groups along the Na-O anti-correlation, with a gap at [O/Na] 0 dex. Na-rich, second generation stars show a trend to be more centrally concentrated, although the level of confidence is not very high. When compared to the classical second-parameter twin NGC 288, with similar metallicity, but different horizontal branch type and much lower total mass, the proton-capture processing in stars of NGC 362 seems to be more extreme, confirming previous analysis. We discovered the presence of a secondary RGB sequence, redder than the bulk of the RGB: a preliminary estimate shows that this sequence comprises about 6% of RGB stars. Our spectroscopic data and literature photometry indicate that this sequence is populated almost exclusively by giants rich in Ba, and probably rich in all s-process elements, as found in other clusters. In this regards, NGC 362 joins previously studied GCs like NGC 1851, NGC 6656 (M 22), and NGC 7089 (M 2).

### UHECR: Signatures and Models

The signatures of Ultra High Energy (E >1 EeV) proton propagation through CMB radiation are pair-production dip and GZK cutoff. The visible characteristics of these two spectral features are ankle, which is intrinsic part of the dip, beginning of GZK cutoff in the differential spectrum and E_{1/2} in integral spectrum. Measured by HiRes and Telescope Array (TA) these characteristics agree with theoretical predictions. However, directly measured mass composition remains a puzzle. While HiRes and TA detectors observe the proton dominated mass composition, the data of Auger detector strongly evidence for nuclei mass composition becoming progressively heavier at energy higher than 4 EeV and reaching Iron at energy about 35 EeV. The models based on the Auger and HiRes/TA data are considered independently and classified using the transition from galactic to extragalactic cosmic rays. The ankle cannot provide this transition. since data of all three detector at energy (1 – 3) EeV agree with pure proton composition (or at least not heavier than Helium). If produced in Galaxy these particles result in too high anisotropy. This argument excludes or strongly disfavours all ankle models with ankle energy E_a > 3 EeV. The calculation of elongation curves, X_{\max}(E), for different ankle models strengthens further this conclusion. Status of other models, the dip, mixed composition and Auger based models are discussed.

### The Pierre Auger Observatory: results on the highest energy particles

The Pierre Auger Observatory has been designed to investigate the most energetic particles known, the ultra high energy cosmic rays. The observatory, covering an area of 3000 km^2, combines two different detection techniques to study the huge particle showers created by the interaction of primary cosmic rays with the atmosphere. The analysis of the showers allows one to extract information on the nature of the primary cosmic rays, as well as their origin. Moreover, the study of the interaction of these particles with the atmosphere offers a unique window to study particle physics at an energy more than one order of magnitude above the current highest energy human-made accelerator. In this contribution selected results are presented, with a focus on the primary mass composition, the determination of the number of muons, which is sensitive to the shower hadronic interactions, and the measurement of the proton-air cross-section at sqrt(s) = 57 TeV. For the last topic, a link with the proton-proton cross-section measurements using accelerators will be made. Results on the cosmic ray energy spectrum and on searches for ultra high energy photons and neutrinos, will also be discussed.

### Observational Test of Stochastic Heating in Low-$\beta$ Fast Solar Wind Streams

Spacecraft measurements show that protons undergo substantial perpendicular heating during their transit from the Sun to the outer heliosphere. In this paper, we use {\em Helios~2} measurements to investigate whether stochastic heating by low-frequency turbulence is capable of explaining this perpendicular heating. We analyze {\em Helios~2} magnetic-field measurements in low-$\beta$ fast-solar-wind streams between heliocentric distances $r=0.29$ AU and $r=0.64$ AU to determine the rms amplitude of the fluctuating magnetic field, $\delta B_{\rm p}$, near the proton gyroradius scale $\rho_{\rm p}$. We then evaluate the stochastic heating rate $Q_{\perp \rm stoch}$ using the measured value of $\delta B_{\rm p}$ and a previously published analytical formula for $Q_{\perp \rm stoch}$. Using {\em Helios} measurements we estimate the empirical’ perpendicular heating rate $Q_{\perp \rm emp} = (k_{\rm B}/m_{\rm p}) B V (d/dr) (T_{\perp \rm p}/B)$ that is needed to explain the $T_{\perp \rm p}$ profile. We find that $Q_{\perp \rm stoch} \sim Q_{\perp \rm emp}$, but only if a key dimensionless constant appearing in the formula for $Q_{\perp \rm stoch}$ lies within a certain range of values. This range is approximately the same throughout the radial interval that we analyze and is consistent with the results of numerical simulations of the stochastic heating of test particles in reduced magnetohydrodynamic turbulence. These results support the hypothesis that stochastic heating accounts for much of the perpendicular proton heating occurring in low-$\beta$ fast-wind streams.

### Bi-Directional Energy Cascades and the Origin of Kinetic Alfv\'enic and Whistler Turbulence in the Solar Wind

The observed sub-proton scale turbulence spectrum in the solar wind raises the question of how that turbulence originates. Observations of keV energetic electrons during solar quite-time suggest them as possible source of free energy to drive the turbulence. Using particle-in-cell simulations, we explore how free energy in energetic electrons, released by an electron two-stream instability drives Weibel-like electromagnetic waves that excite wave-wave interactions. Consequently, both kinetic Alfv\’enic and whistler waves are excited that evolve through inverse and forward magnetic energy cascades.

### A new physical phenomenon in ultra-high energy collisions [Cross-Listing]

We show that combining the published Pierre Auger Observatory measurements of the longitudinal_and_ lateral properties of UHE atmospheric showers, points to an unforeseen change in the nature of particle interactions at ultrahigh energy. A "toy model" of UHE proton-air interactions is presented which provides the first fully consistent description of air shower observations. It demonstrates that the observed energy dependence of the depth-of-shower-maximum distribution may not indicate a transition to a heavier composition, as commonly assumed. While fundamentally phenomenological, the model is based on considerations of how the normal vacuum of QCD might be vaporized and chiral symmetry restored by the extreme energy densities produced in UHE collisions. Whatever its origin, understanding this unexpected phenomenon opens exciting directions in particle physics and may impact Early Universe cosmology.

### Instabilities Driven by the Drift and Temperature Anisotropy of Alpha Particles in the Solar Wind [Replacement]

We investigate the conditions under which parallel-propagating Alfv\’en/ion-cyclotron (A/IC) waves and fast-magnetosonic/whistler (FM/W) waves are driven unstable by the differential flow and temperature anisotropy of alpha particles in the solar wind. We focus on the limit in which $w_{\parallel \alpha} \gtrsim 0.25 v_{\mathrm A}$, where $w_{\parallel \alpha}$ is the parallel alpha-particle thermal speed and $v_{\mathrm A}$ is the Alfv\’en speed. We derive analytic expressions for the instability thresholds of these waves, which show, e.g., how the minimum unstable alpha-particle beam speed depends upon $w_{\parallel \alpha}/v_{\mathrm A}$, the degree of alpha-particle temperature anisotropy, and the alpha-to-proton temperature ratio. We validate our analytical results using numerical solutions to the full hot-plasma dispersion relation. Consistent with previous work, we find that temperature anisotropy allows A/IC waves and FM/W waves to become unstable at significantly lower values of the alpha-particle beam speed $U_\alpha$ than in the isotropic-temperature case. Likewise, differential flow lowers the minimum temperature anisotropy needed to excite A/IC or FM/W waves relative to the case in which $U_\alpha =0$. We discuss the relevance of our results to alpha particles in the solar wind near 1 AU.

### Instabilities Driven by the Drift and Temperature Anisotropy of Alpha Particles in the Solar Wind [Cross-Listing]

We investigate the conditions under which parallel-propagating Alfv\’en/ion-cyclotron (A/IC) waves and fast-magnetosonic/whistler (FM/W) waves are driven unstable by the differential flow and temperature anisotropy of alpha particles in the solar wind. We focus on the limit in which $w_{\parallel \alpha} \gtrsim 0.25 v_{\mathrm A}$, where $w_{\parallel \alpha}$ is the parallel alpha-particle thermal speed and $v_{\mathrm A}$ is the Alfv\’en speed. We derive analytic expressions for the instability thresholds of these waves, which show, e.g., how the minimum unstable alpha-particle beam speed depends upon $w_{\parallel \alpha}/v_{\mathrm A}$, the degree of alpha-particle temperature anisotropy, and the alpha-to-proton temperature ratio. We validate our analytical results using numerical solutions to the full hot-plasma dispersion relation. Consistent with previous work, we find that temperature anisotropy allows A/IC waves and FM/W waves to become unstable at significantly lower values of the alpha-particle beam speed $U_\alpha$ than in the isotropic-temperature case. Likewise, differential flow lowers the minimum temperature anisotropy needed to excite A/IC or FM/W waves relative to the case in which $U_\alpha =0$. We discuss the relevance of our results to alpha particles in the solar wind near 1 AU.

### Isospin-Violating Dark Matter Benchmarks for Snowmass 2013 [Replacement]

Isospin-violating dark matter (IVDM) generalizes the standard spin-independent scattering parameter space by introducing one additional parameter, the neutron-to-proton coupling ratio f_n/f_p. In IVDM the implications of direct detection experiments can be altered significantly. We review the motivations for considering IVDM and present benchmark models that illustrate some of the qualitatively different possibilities. IVDM strongly motivates the use of a variety of target nuclei in direct detection experiments.

### Isospin-Violating Dark Matter Benchmarks for Snowmass 2013 [Cross-Listing]

Isospin-violating dark matter (IVDM) generalizes the standard spin-independent scattering parameter space by introducing one additional parameter, the neutron-to-proton coupling ratio f_n/f_p. In IVDM the implications of direct detection experiments can be altered significantly. We review the motivations for considering IVDM and present benchmark models that illustrate some of the qualitatively different possibilities. IVDM strongly motivates the use of a variety of target nuclei in direct detection experiments.

### The Space-Based Gamma-Ray Telescope GAMMA-400 and Its Scientific Goals

The design of the new space-based gamma-ray telescope GAMMA-400 is presented. GAMMA-400 is optimized for the energy 100 GeV with the best parameters: the angular resolution ~0.01 deg, the energy resolution ~1%, and the proton rejection factor ~10E6, but is able to measure gamma-ray and electron + positron fluxes in the energy range from 100 MeV to 10 TeV. GAMMA-400 is aimed to a broad range of science topics, such as search for signatures of dark matter, studies of Galactic and extragalactic gamma-ray sources, Galactic and extragalactic diffuse emission, gamma-ray bursts, as well as high-precision measurements of spectra of cosmic-ray electrons + positrons, and nuclei.

### Proton Radiation Damage Experiment on P-Channel CCD for an X-ray CCD camera onboard the Astro-H satellite

We report on a proton radiation damage experiment on P-channel CCD newly developed for an X-ray CCD camera onboard the Astro-H satellite. The device was exposed up to 10^9 protons cm^{-2} at 6.7 MeV. The charge transfer inefficiency (CTI) was measured as a function of radiation dose. In comparison with the CTI currently measured in the CCD camera onboard the Suzaku satellite for 6 years, we confirmed that the new type of P-channel CCD is radiation tolerant enough for space use. We also confirmed that a charge-injection technique and lowering the operating temperature efficiently work to reduce the CTI for our device. A comparison with other P-channel CCD experiments is also discussed.


text:
# Exact Poisson CI

#### katxt

##### Well-Known Member

Hi. This is given as the "exact" CI for a Poisson rate in many places. k is the observed number, mu is the true rate. My problem is the different df at each end. When alpha gets large and tends to 100% you would expect the limits to converge on k. They don't.
Is there a real "exact" CI for which you can put in large values of alpha and have it work?

Last edited:

#### hlsmith

##### Less is more. Stay pure. Stay poor.
Not looking at the equation, philosophically I always wondered when younger what is the true population size and how would the function know that since we never have knowledge of the truth and the truth is always changing given all data can't be collected simultaneously and there always seems to be epistemological error. You could simulate but the error comes into play, so hey simulate it deterministically, well that converges prior to having the full sample (likely).

It seems many precision bounds are exact in small sample setting and asymptotic in larger settings. The +2 seems like one of those sample estimate things with d's that has never clicked in my head kind of like prediction intervals.

#### katxt

##### Well-Known Member
Thanks. I'm not much further on, but I appreciate your deep philosophical thoughts about truth, the meaning of life and the pursuit of happiness. kat

#### Dason

Can you provide a link to any source listing that as "exact"?

#### katxt

##### Well-Known Member
Here's the background. I want a way of generating a range of plausible mu's when k = 1 for a monte carlo analysis. I hoped to use the exact CI equation with alpha uniform on 0-1 but that doesn't work.
I have tried using the Poisson likelihood function for k = 1 but the values I get for 95% CI don't match the "exact" formula. I have also tries approximating the Poisson for k = 1 with the binomial for a very large number but that doesn't match either.
Any suggestions?

#### Dason

Could use the posterior distribution you'd get from a bayesian analysis for that I would think.

#### katxt

##### Well-Known Member
Thanks. Good thought. I'm not too hot on Bayesian stuff, but a uniform prior seems to give (I think) more or less the same results as the likelihood function.

#### Dason

As it should. But simulating from the likelihood isn't really defensible from a frequentist perspective. I'm being pedantic but if that's what you want to do it really makes the most sense to at least acknowledge you're taking a bayesian approach.

Last edited:

#### katxt

##### Well-Known Member
OK. I just thought it was common sense. Perhaps I'm a closet Bayesian.

#### katxt

##### Well-Known Member
Just in case anyone is following this, I was looking for a function to generate Monte Carlo Poisson rates given an observation k.
Given the "exact" CI expression I used mu = 1/2*CHIINV(k,2*(n+k)), where u is Uniform(0,1). This gives about 2k df for small values of u, and 2k+2 df for large u. It seems to work well enough but any further suggestions appreciated. kat

Last edited:


text:
# Error: [file_contents,C:\HaxeToolkit\haxe\lib\lime/.current]

i instaledl openfl the latest version ,But when i tried to update it i get this error

Error: [file_contents,C:\HaxeToolkit\haxe\lib\lime/.current]

What that means is that it called a function named file_contents(), with “C:\HaxeToolkit\haxe\lib\lime/.current” as the one argument.

In other words, it tried to get the contents of this “.current” file, and it couldn’t. Are you sure the file is there? If not, run haxelib set lime [version].


text:
# Question about the start of a cosine fourier series

1. May 2, 2012

### deckoff9

Question about the "start" of a cosine fourier series

Hey. I was just looking through Paul's Online Notes http://tutorial.math.lamar.edu/Classes/DE/FourierCosineSeries.aspx to teach myself Fourier Series and I had a question about the a$_{0}$ term of the cosine series.

In the online lesson, it says assume an even function has the series f(x) = $\Sigma$a$_{n}$cos(n$\pi$x/L) where -L≤x≤L. The series starts at 0, and the way Paul gave a prove of it was to multiply the series by cos(m$\pi$x/L) and then integrated and used the fact that cos(m$\pi$x/L) and cos(n$\pi$x/L) were orthogonal if m!=n.

So that for example, for the fourier series of x$^{2}$, he got a$_{0}$ = L$^{2}$/3, where -L≤x≤L.

However, my question is, why do we need to start at n = 0? The proof using orthogonality would work just as well if n were to start at 1 or 100, and the formula for the coefficients would remain the same. In addition, I'm not sure convergence explains it, since the beginning terms of a infinite series have no effect on the convergence of an infinite series. So I was hoping someone could clear this up for me.

2. May 2, 2012

### HallsofIvy

Staff Emeritus
Re: Question about the "start" of a cosine fourier series

Changing or deleting a finite number of terms will not change whether or not the series converges but it surely changes what it converge to!

3. May 2, 2012

Re: Question about the "start" of a cosine fourier series

You're making use of the fact that the set of ${ \cos \frac{n \pi x}{L} }$ for all integers n serves as a complete basis for even functions on the interval L. Without the $n = 0$ term, you don't have a complete basis and thus can't span the space of even continuous on this interval (in reality, the space this set spans is a little bigger than just continuous even functions, but for brevity of the conversation, I've cut it down).

At its heart the fourier expansion is based in applications of linear algebra, hence why my explanation is based in linear algebra terms. If you struggle with the explanation, you should look into some basic linear algebra concepts and definitions. These expansions are one of my favorite examples of "hidden" linear algebra.

4. May 2, 2012

### deckoff9

Re: Question about the "start" of a cosine fourier series

Thanks for the answers guys! It helped clear up my confusion a lot.


text:
LaTeX forum ⇒ Text Formatting ⇒ Same Alignment for Text as for Heading Topic is solved

Information and discussion about LaTeX's general text formatting features (e.g. bold, italic, enumerations, ...)
Lalitp
Posts: 6
Joined: Sat Apr 06, 2013 8:25 am

Same Alignment for Text as for Heading  Topic is solved

Here you can see that "Quality Control/Inspection" is at left side in generated PDF, and other content is displaced by some space.
\documentclass[12pt]{article} \begin{document}   \tableofcontents    \section{Advantages}    \subsubsection{Application Areas}Quality Control / Inspection Comparison of actual data with nominal data  Mold and Toolmaking Tool reconstruction Scan data for generation of milling tool paths Documentation of actual 3D data at tool release \end{document}

I want all contents same as "Quality Control/Inspection" position.

So, what modification is necessary in script?
Last edited by localghost on Sun Apr 07, 2013 9:53 am, edited 2 times in total.
Reason: Source code has to be tagged as such to keep a post clear and legible (see Board Rules).

Tags:

localghost
Site Moderator
Posts: 9204
Joined: Fri Feb 02, 2007 12:06 pm
An identical problem has already been discussed in one of your other questions.

Thorsten
LaTeX Community Moderator

¹ System: openSUSE 42.2 (Linux 4.4.52), TeX Live 2016 (vanilla), TeXworks 0.6.1

Stefan Kottwitz
Posts: 9504
Joined: Mon Mar 10, 2008 9:44 pm
It appreciate that you posted a compilable example. Also very good that you added tags, even if not perfectly matching, I changed them. Tags help to get the forum sorted.

To your problem, which is actually similar to the earlier question, perhaps the intention may be a bit different. If you want to change the alignment of those lines, which is the paragraph indentation, you can switch it off by

\setlength{\parindent}{0pt}

in your preamble. Then all those lines are left aligned with the headings. However, paragraph indentation helps to see where a paragraph ended and a new one started. So, either change those lines to headings, such as with \subsection, \subsubsection or \paragraph, or insert \noindent before such pseudo-headings, or change the paragraph indentation mode to vertical paragraph skips by

\usepackage{parskip}


text:
# Hermite (physicist) polynomial at negative argument

The following formula holds: $$H_n(-x)=(-1)^n H_n(x),$$ where $H_n$ denotes a physicist's Hermite polynomial.