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We revise general relativity (GR) from the perspective of calculus for moving surfaces (CMS). While GR is intrinsically constructed in pseudo-Riemannian geometry, a complete understanding of moving manifolds requires embedding in a higher…

General Relativity and Quantum Cosmology · Physics 2024-06-13 David V. Svintradze

A Monte Carlo generator of high energy cosmic ray interactions, relying on a very basic and transparent theoretical formalism, in the framework of the Reggeon Field Theory, is presented. The main motivation for our work is to provide a new…

High Energy Physics - Phenomenology · Physics 2026-03-16 Sergey Ostapchenko , Tanguy Pierog , Günter Sigl

This paper presents an introduction to the astrophysics of cosmic rays and diffuse gamma rays and discusses some of the puzzles that have emerged recently due to more precise data and improved propagation models: the excesses in Galactic…

Astrophysics · Physics 2008-11-26 I. V. Moskalenko

In recent years, the freely available Monte Carlo code REAS for modelling radio emission from cosmic ray air showers has evolved to include the full complexity of air shower physics. However, it turned out that in REAS2 and all other…

High Energy Astrophysical Phenomena · Physics 2010-10-27 Marianne Ludwig , Tim Huege

Most studies of GeV Galactic Cosmic Rays (GCR) nuclei assume a steady state/continuous distribution for the sources of cosmic rays, but this distribution is actually discrete in time and in space. The current progress in our understanding…

We present the temporal changes of the diffusion coefficient K of galactic cosmic rays (GCRs) at the Earth orbit calculated based on the experimental data using two different methods. The first approach is based on the Parker…

Space Physics · Physics 2015-02-04 Renata Modzelewska

Over the past years, the freely available Monte Carlo-code REAS which simulates radio emission from air showers based on the geosynchrotron model, was used regularly for comparisons with data. However, it emerged that in the previous…

High Energy Astrophysical Phenomena · Physics 2010-09-13 Marianne Ludwig , Tim Huege

The task of Monte Carlo simulation of the evolution of the parton distributions in QCD and of constructing new parton shower Monte Carlo algorithms requires new way of organizing solutions of the QCD evolution equations, in which…

High Energy Physics - Phenomenology · Physics 2010-03-25 S. Jadach , M. Skrzypek , Z. Was

Variations in the flux of Galactic Cosmic Rays (GCR) at Earth during the last 4.6 billion years are constructed from information about the Star Formation Rate (SFR) in the Milky Way and the evolution of solar activity. The variations of GCR…

Space Physics · Physics 2007-05-23 Henrik Svensmark

Ultra-high energy cosmic rays can be measured through the detection of radio-frequency radiation from air showers. The radio-frequency emission originates from deflections of the air-shower particles in the geomagnetic field and from a…

High Energy Astrophysical Phenomena · Physics 2018-10-01 Christian Glaser , Sijbrand de Jong , Martin Erdmann , Jörg R. Hörandel

An extensive program for the calculation of galactic cosmic-ray propagation has been developed. This is a continuation of the work described in Strong & Youssefi (1995). The main motivation for developing this code is the prediction of…

Astrophysics · Physics 2009-10-30 A. W. Strong , I. V. Moskalenko

We present an introductory lecture on general features of cosmic rays, for non-experts, and some recent developments concerning cascade equations for air shower developments.

Astrophysics · Physics 2007-05-23 K. Werner , V. Chernatkin , R. Engel , N. N. Kalmykov , S. Ostapchenko , T. Pierog

The study of Gamma Ray Bursts (GRBs) has the potential to improve our understanding of high energy astrophysical phenomena. In order to reliably use GRBs to this end, we first need to have a well-developed grasp of the mechanism that…

High Energy Astrophysical Phenomena · Physics 2021-10-26 Tyler Parsotan , Davide Lazzati

We develop a novel Monte Carlo parton branching algorithm based on the Gribov-Levin-Ryskin (GLR) equation. The formulations of both forward evolution and backward evolution for the GLR equation are presented. The results from the Monte…

High Energy Physics - Phenomenology · Physics 2023-02-08 Yu Shi , Shu-Yi Wei , Jian Zhou

Traditional approaches to the study of the dynamics of spacetime curvature in a very real sense hide the intricacies of the nonlinear regime. Whether it be huge formulae, or mountains of numerical data, standard methods of presentation make…

General Relativity and Quantum Cosmology · Physics 2013-05-30 Kayll Lake

We review some of the recent progress in our knowledge about high-energy cosmic rays, with an emphasis on the interpretation of the different observational results. We discuss the effects that are relevant to shape the cosmic ray spectrum…

High Energy Astrophysical Phenomena · Physics 2017-12-05 Silvia Mollerach , Esteban Roulet

The actual accelerated expansion of the universe continues being a mystery in physics. Some models had been proposed for this explanations, among them the dark energy, which however has problems of experimental character as well as…

General Relativity and Quantum Cosmology · Physics 2012-11-13 Alejandro Guarnizo

This perspective provides a succinct history of Fermi's golden rule (FGR), overview of its derivation, assumptions, and representative forms. Major applications of FGR, mostly in the field of chemical physics, are reviewed. These illustrate…

Chemical Physics · Physics 2026-04-13 Seogjoo J. Jang , Goun Kim , Young Min Rhee

We use a new method of analysis to determine parameters of cosmological gamma-ray bursts (GRBs), assuming that their distribution follows the star-formation history of the universe. Spectral evolution is calculated from an external shock…

Astrophysics · Physics 2015-06-24 M. Boettcher , C. D. Dermer

Modified General Relativity (MGR) is the natural extension of General Relativity (GR). MGR explicitly uses the smooth regular line element vector field $(\bm{X},-\bm{X}) $, which exists in all Lorentzian spacetimes, to construct a…

General Relativity and Quantum Cosmology · Physics 2026-01-27 Gary Nash