English
Related papers

Related papers: A C++ Code to Solve the DGLAP Equations Applied to…

200 papers

We argue that an astrophysical solution to UHECR problem is viable. The pectral features of extragalactic protons interacting with CMB are calculated in model-independent way. Using the power-law generation spectrum $\propto E^{-\gamma_g}$…

High Energy Physics - Phenomenology · Physics 2014-11-17 V. Berezinsky , A. Z. Gazizov , S. I. Grigorieva

Nonlinear differential equations are challenging to solve numerically and are important to understanding the dynamics of many physical systems. Deep neural networks have been applied to help alleviate the computational cost that is…

Numerical Analysis · Mathematics 2020-10-27 Bryce Chudomelka , Youngjoon Hong , Hyunwoo Kim , Jinyoung Park

Dihadron fragmentation functions and their evolution are studied in the process of $e^+e^-$ annihilation. Under the collinear factorization approximation and facilitated by the cut-vertex technique, the two hadron inclusive cross section at…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. Majumder , Xin-Nian Wang

The origin and nature of ultrahigh energy cosmic rays with energies above $10^{20}\,$eV is a puzzle for the physics and astrophysics of cosmic rays which is still unresolved. In this paper, I report on an extensive study on the propagation…

Astrophysics · Physics 2009-10-28 Sangjin Lee

We present a new approach for the identification of ultra-high energy cosmic rays from sources using dynamic graph convolutional neural networks. These networks are designed to handle sparsely arranged objects and to exploit their short-…

High Energy Astrophysical Phenomena · Physics 2020-12-09 Teresa Bister , Martin Erdmann , Jonas Glombitza , Niklas Langner , Josina Schulte , Marcus Wirtz

Fostered by upcoming data from new generation observational campaigns, we are about to enter a new era for the study of how galaxies form and evolve. The unprecedented quantity of data that will be collected, from distances only marginally…

Modern cosmological surveys such as the Hyper Suprime-Cam (HSC) survey produce a huge volume of low-resolution images of both distant galaxies and dim stars in our own galaxy. Being able to automatically classify these images is a…

Instrumentation and Methods for Astrophysics · Physics 2020-10-14 Imène R. Goumiri , Amanda L. Muyskens , Michael D. Schneider , Benjamin W. Priest , Robert E. Armstrong

We analyze the spectrum of the ultrahigh energy (above \approx 10^{9} GeV) cosmic rays. With a maximum likelihood analysis we show that the observed spectrum is consistent with the decay of extragalactic GUT scale particles. The predicted…

High Energy Physics - Phenomenology · Physics 2007-05-23 Z. Fodor , S. D. Katz

We present Sapphire++, an open-source code designed to numerically solve the Vlasov-Fokker-Planck equation for astrophysical applications. Sapphire++ employs a numerical algorithm based on a spherical harmonic expansion of the distribution…

High Energy Astrophysical Phenomena · Physics 2025-01-10 Nils W. Schween , Florian Schulze , Brian Reville

A new general Lie-algebraic approach is proposed to solving evolution tasks in some nonlinear problems of quantum physics with polynomially deformed Lie algebras $su_{pd}(2)$ as their dynamic symmetry algebras. The method makes use of an…

High Energy Physics - Theory · Physics 2009-10-28 Valery P. Karassiov , Andrei B. Klimov

We present a general abstract framework for the systematic numerical approximation of dissipative evolution problems. The approach is based on rewriting the evolution problem in a particular form that complies with an underlying energy or…

Numerical Analysis · Mathematics 2018-04-25 Herbert Egger

The ultra-relativistic Euler equations for an ideal gas are described in terms of the pressure, the spatial part of the dimensionless four-velocity and the particle density. Radially symmetric solutions of these equations are studied in two…

Mathematical Physics · Physics 2024-02-21 Matthias Kunik , Adrian Kolb , Siegfried Müller , Ferdinand Thein

Hypergeometric solutions to the q-Painlev\'e equations are constructed by direct linearization of disrcrete Riccati equations. The decoupling factors are explicitly determined so that the linear systems give rise to q-hypergeometric…

Exactly Solvable and Integrable Systems · Physics 2007-05-23 Kenji Kajiwara , Tetsu Masuda , Masatoshi Noumi , Yasuhiro Ohta , Yasuhiko Yamada

The complex interplay of processes at the Galactic Center is at the heart of numerous past, present, and (likely) future mysteries. We aim at a more complete understanding of how spectra extending to >10 TeV result. We first construct a…

High Energy Astrophysical Phenomena · Physics 2016-11-29 Matthew D. Kistler

We present an updated version of the {\it SimProp} Monte Carlo code to study the propagation of ultra high energy cosmic rays in astrophysical backgrounds computing the cosmogenic neutrino fluxes expected on earth. The study of secondary…

High Energy Astrophysical Phenomena · Physics 2015-08-11 R. Aloisio , D. Boncioli , A. di Matteo , A. F. Grillo , S. Petrera , F. Salamida

We present an analytic solution to diffusion equation for high energy cosmic rays in the expanding universe. The particles are assumed to be ultra-relativistic and they can have energy losses arbitrarily dependent on energy and time. The…

Astrophysics · Physics 2009-11-13 V. Berezinsky , A. Z. Gazizov

In the present paper, we present some numerical methods for computing approximate solutions to some large differential linear matrix equations. In the first part of this work, we deal with differential generalized Sylvester matrix equations…

Numerical Analysis · Computer Science 2018-05-28 M. Hached , K. Jbilou

We present the program EvolFMC v.2 that solves the evolution equations in QCD for the parton momentum distributions by means of the Monte Carlo technique based on the Markovian process. The program solves the DGLAP-type evolution as well as…

High Energy Physics - Phenomenology · Physics 2009-12-04 S. Jadach , W. Placzek , M. Skrzypek , P. Stoklosa

We provide a mathematical framework for studying different versions of discontinuous Galerkin (DG) approaches for solving 2D Riemann-Liouville fractional elliptic problems on a finite domain. The boundedness and stability analysis of the…

Numerical Analysis · Mathematics 2018-04-19 Tarek Aboelenen

The last two decades witnessed the increasing of the interests on the absolute value equations (AVE) of finding $x\in\mathbb{R}^n$ such that $Ax-|x|-b=0$, where $A\in \mathbb{R}^{n\times n}$ and $b\in \mathbb{R}^n$. In this paper, we pay…

Optimization and Control · Mathematics 2022-02-15 Cairong Chen , Dongmei Yu , Deren Han