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Cosmic ray air showers are known to emit pulsed radio emission at frequencies around a few tens of MHz. Accompanying the experimental efforts of the LOPES project, situated at the KASCADE-Grande site of the Forschungszentrum Karlsruhe, we…

Astrophysics · Physics 2007-05-23 Tim Huege , Heino Falcke

Three theoretical criteria for gravitational theories beyond general relativity are considered: obtaining the cosmological constant as an integration constant, deriving the energy conservation law as a consequence of the field equations,…

General Relativity and Quantum Cosmology · Physics 2023-08-17 Junpei Harada

On their way through the heliosphere, Galactic Cosmic Rays (GCRs) are modulated by various effects before they can be detected at Earth. This process can be described by the Parker equation, which calculates the phase space distribution of…

Space Physics · Physics 2017-11-28 Jan Gieseler , Bernd Heber , Konstantin Herbst

A numerical method for integrating the equations describing a dynamically coupled system made of a fluid and cosmic-rays is developed. In smooth flows the effect of CR pressure is accounted for by modification of the characteristic…

Astrophysics · Physics 2008-11-26 Francesco Miniati

We represent the method of dynamic diffusion for the approximate solution of Shroedinger equation with decoherence. Decoherence shows as the divergency of exact solution from the dynamics of diffusion swarm, which arises when the total…

Quantum Physics · Physics 2011-05-04 V. Kukushkin , Y. I. Ozhigov

We investigate the evolution of the linear cosmological perturbations in f(R) gravity, an alternative to dark energy for explaining the late-time cosmic acceleration. We numerically calculate the early-time evolution with an approximation…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-16 Je-An Gu , Tse-Chun Wang , Yen-Ting Wu , Pisin Chen , W-Y. Pauchy Hwang

I describe a new approach (developed in collaboration with D.E. Holz) to calculating the statistical distributions for magnification, shear, and rotation of images of cosmological sources due to gravitational lensing by mass inhomogeneities…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Robert M. Wald

We analyze isothermal aging of a four dimensional Edwards-Anderson model in detail by Monte Carlo simulations. We analyze the data in the view of an extended version of the droplet theory proposed recently (cond-mat/0202110) which is based…

Disordered Systems and Neural Networks · Physics 2009-11-07 Hajime Yoshino , Koji Hukushima , Hajime Takayama

We construct a class of generalized non-local gravity (GNLG) model which is the modified theory of general relativity (GR) obtained by adding a term $m^{2n-2} R\Box^{-n}R$ to the Einstein-Hilbert action. Concretely, we not only study the…

General Relativity and Quantum Cosmology · Physics 2016-11-23 Xue Zhang , Ya-Bo Wu , Song Li , Yu-Chen Liu , Bo-Hai Chen , Yun-Tian Chai , Shuang Shu

The formation and chemical evolution of the Milky Way Galaxy is numerically simulated by developing a Monte Carlo approach to predict the elemental abundance gradients and other galactic features using the revised solar abundance. The…

Astrophysics of Galaxies · Physics 2018-10-10 Sandeep Sahijpal , Tejpreet Kaur

One of the methods for studying the highest energy cosmic rays is to measure the fluorescence light emitted by the extensive air showers induced by them. To reconstruct a shower cascade curve from measurements of the number of photons…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Maria Giller , Andrzej Smialkowski

A scalar, preferred-frame theory of gravitation is summarized. Space-time is endowed with both a flat metric and a curved, "physical" metric. Motion is governed by a natural extension of Newton's second law, which implies geodesic motion…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Mayeul Arminjon

Two different ways of generalizing Einstein's general theory of relativity with a cosmological constant to Brans-Dicke type scalar-tensor theories are investigated in the linearized field approximation. In the first case a cosmological…

General Relativity and Quantum Cosmology · Physics 2018-02-07 Hatice Özer , Özgür Delice

The physics content of the QGSJET-III Monte Carlo model of high energy hadronic interactions is briefly described. The predictions of the model for extensive air shower characteristics are presented in comparison to the corresponding…

High Energy Physics - Phenomenology · Physics 2024-11-06 Sergey Ostapchenko

We present a solution to the apparent discrepancy between the radial gradient in the diffuse Galactic gamma-ray emissivity and the distribution of supernova remnants, believed to be the sources of cosmic rays. Recent determinations of the…

Astrophysics · Physics 2009-11-10 A. W. Strong , I. V. Moskalenko , O. Reimer , S. Digel , R. Diehl

The work is devoted to the critical analysis of theoretical prediction and astronomical observation of GR effects, first of all, the Mercury's perihelion advance. In the first part, the methodological issues of observations are discussed…

General Physics · Physics 2010-08-12 Anatoli A. Vankov

The path length distribution of Galactic cosmic rays (GCRs) is the fundamental ingredient for modeling the propagation process of GCRs based on the so-called weighted slab method. We try to derive this distribution numerically by taking…

High Energy Astrophysical Phenomena · Physics 2015-01-14 S. Miyake , H. Muraishi , S. Yanagita

Gravitation might make a preferred frame appear, and with it a clear space/time separation--the latter being, a priori, needed by quantum mechanics (QM) in curved space-time. Several models of gravitation with an ether are discussed: they…

General Relativity and Quantum Cosmology · Physics 2008-04-07 Mayeul Arminjon

The Galileon model is a modified gravity theory that may provide an explanation for the accelerated expansion of the Universe. This model does not suffer from instabilities or ghost problems (normally associated with higher-order derivative…

General Relativity and Quantum Cosmology · Physics 2013-07-02 J. Neveu , V. Ruhlmann-Kleider , A. Conley , N. Palanque-Delabrouille , P. Astier , J. Guy , E. Babichev

We discuss the galaxy clustering based on thermodynamics and statistical mechanics in the expanding universe in a modified theory of gravity. The modified general relativity (MGR) is developed using the regular line element field to…

General Physics · Physics 2023-02-15 Abdul W. Khanday , Sudhaker Upadhyay , Prince A. Ganai