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Related papers: Photon dispersion in causal sets

200 papers

One of the predictions of quantum gravity phenomenology is that, in situations where Planck-scale physics and the notion of a quantum spacetime are relevant, field propagation will be described by a modified set of laws. Descriptions of the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Luca Bombelli , Oliver Winkler

United classification of gamma-ray bursts and their counterparts is established on the basis of measured characteristics: photon energy E and emission duration T. The founded interrelation between the mentioned characteristics of events…

Astrophysics · Physics 2008-11-26 Alexander Kuznetsov

Whatever the ultimate energy source of gamma-ray bursts turns out to be, the resulting sequence of physical events is likely to lead to a fairly generic, almost unavoidable scenario: a relativistic fireball that dissipates its energy after…

Astrophysics · Physics 2016-08-30 P. Meszaros

Fenimore et al. (1995) have recently presented a very tight correlation between the spectral and the temporal structure in Gamma Ray Bursts (hereafter GRBs). In particular, they discovered that the durations of the constituent subpulses…

Astrophysics · Physics 2009-10-30 Demosthenes Kazanas , Lev G. Titarchuk , Xin-Min Hua

Energy spectra of particles accelerated by the first-order Fermi mechanism are investigated at ultrarelativistic shock waves, outside the range of Lorentz factors considered previously. For particle transport near the shock a numerical…

Astrophysics · Physics 2011-05-05 J. Bednarz , M. Ostrowski

The dispersion of fast radio bursts (FRBs) is a measure of the large-scale electron distribution. It enables measurements of cosmological parameters, especially of the expansion rate and the cosmic baryon fraction. The number of events is…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-19 Robert Reischke , Steffen Hagstotz

Both long and short gamma-ray bursts (GRBs) are expected to occur in the dense environments of active galactic nuclei (AGN) accretion disks. As these bursts propagate through the disks they live in, they photoionize the medium causing…

High Energy Astrophysical Phenomena · Physics 2023-03-29 Michael Ray , Davide Lazzati , Rosalba Perna

We calculate the statistical distribution of observed afterglow flux, in some fixed observed frequency band, and at some fixed observer time after the explosion ($t_{obs}$) in two models - one where the explosion takes place in a uniform…

Astrophysics · Physics 2009-10-31 Pawan Kumar

Photon is the fundamental quantum of electromagnetic fields, whose mass, $m_{\gamma}$, should be strictly zero in Maxwell's theory. But not all theories adopt this hypothesis. If the rest mass of the photon is not zero, there will be an…

High Energy Astrophysical Phenomena · Physics 2021-09-01 Huimei Wang , Xueli Miao , Lijing Shao

The paper explores the fundamental physical principles of quantum mechanics (in fact, quantum field theory) which limit the bit rate for long distances. Propagation of photons in optical fibers is modeled using methods of quantum…

Quantum Physics · Physics 2015-06-17 Andrei Khrennikov , Börje Nilsson , Sven Nordebo , Igor Volovich

The `missing baryons' of the near universe are believed to be principally in a partially ionized state. Although passing electromagnetic waves are dispersed by the plasma, the effect has hitherto not been utilized as a means of detection…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Richard Lieu , Lingze Duan , T. W. B. Kibble

We have investigated the time variations in the light curves from a sample of long and short Fermi/GBM Gamma ray bursts (GRBs) using an impartial wavelet analysis. The results indicate that in the source frame, the variability time scales…

High Energy Astrophysical Phenomena · Physics 2015-06-03 G. A. MacLachlan , A. Shenoy , E. Sonbas , K. S. Dhuga , B. Cobb , T. N. Ukwatta , D. C. Morris , A. Eskandarian , L. C. Maximon , W. C. Parke

We investigate the implications of energy-dependence of the speed of photons, one of the candidate effects of quantum-gravity theories that has been most studied recently, from the perspective of observations in different reference frames.…

High Energy Astrophysical Phenomena · Physics 2015-03-14 Uri Jacob , Flavio Mercati , Giovanni Amelino-Camelia , Tsvi Piran

We discuss several constraints on the properties of gamma-ray bursts (GRB) at cosmological distances. First we use the requirement that burst sources must be optically thin to pair production by photon-photon collisions in order to produce…

Astrophysics · Physics 2009-10-28 Eric Woods , Abraham Loeb

Photon counts statistics have recently been proven to provide a sensitive observable for characterizing gamma-ray source populations and for measuring the composition of the gamma-ray sky. In this work, we generalize the use of the standard…

High Energy Astrophysical Phenomena · Physics 2017-02-22 H. -S. Zechlin , A. Cuoco , F. Donato , N. Fornengo , M. Regis

The spatial distribution of sources of gamma-ray bursts (GRB) with known red shifts is analyzed by the conditional density and pairwise distance methods. The sample of GRB is based on data from the Swift mission and contains fluxes,…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-06 S. I. Shirokov , A. A. Raikov , Yu. V. Baryshev

Active galactic nuclei (AGN) with jets seen at small viewing angles are the most luminous and abundant objects in the $\gamma$-ray sky. AGN with jets misaligned along the line-of-sight appear fainter in the sky, but are more numerous than…

High Energy Astrophysical Phenomena · Physics 2015-06-15 M. Di Mauro , F. Calore , F. Donato , M. Ajello , L. Latronico

The number of identified Fast Radio Bursts (FRBs) is increasing rapidly with current and future facilities. Strongly lensed FRBs are expected to be found as well, which can provide precise time delays and thus have rich applications in…

High Energy Astrophysical Phenomena · Physics 2022-08-31 Xinzhong Er , Shude Mao

In this letter a new formula for light deflection is derived using only physically observable concepts. The general result is specialized to cosmological perturbation theory and expressed in terms of gauge--invariant perturbation variables.…

Astrophysics · Physics 2009-10-22 Ruth Durrer

The detection of delayed emission in X-ray, optical and radio wave length, ``afterglow'', following a gamma-ray burst can be described by the emission of a relativistic shell decelerating upon collision with the ISM. We show that the…

Astrophysics · Physics 2009-10-30 Re'em Sari