English
Related papers

Related papers: LQG-modified dispersion relations and the problem …

200 papers

Our present contribution sets out to investigate a scenario based on the effects of the Loop Quantum Gravity (LQG) on the electromagnetic sector of the Standard Model of Fundamental Interactions and Particle Physics (SM). Starting then from…

High Energy Physics - Theory · Physics 2025-11-18 P. A. L. Mourão , G. L. L. W. Levy , J. A. Helayël-Neto

Lorentz invariance violation~(LIV) can change the threshold behavior predicted by special relativity and cause threshold anomalies which affect the propagation of cosmic photons. In this work, we focus on the threshold anomaly effect on…

High Energy Astrophysical Phenomena · Physics 2023-03-07 Hao Li , Bo-Qiang Ma

Lorentz violation (LV) is predicted by some quantum gravity (QG) candidates, wherein the canonical energy-momentum dispersion relation, $E^2=p^2+m^2$, is modified. Consequently, new phenomenons beyond the standard model are predicted.…

High Energy Physics - Phenomenology · Physics 2010-12-07 Lijing Shao , Bo-Qiang Ma

From special relativity, photon annihilation process \HepProcess{{\Pgg}{\Pgg}{\to}{\Pep}{\Pem}} prevents cosmic photons with energies above a threshold to propagate a long distance in cosmic space due to their annihilation with low energy…

High Energy Physics - Phenomenology · Physics 2021-09-15 Hao Li , Bo-Qiang Ma

In quantum theory of gravity, we expect the Lorentz Invariance Violation (LIV) and the modification of the dispersion relation between energy and momentum for photons. The effect of the energy-dependent velocity due to the modified…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-24 Yu Pan , Yungui Gong , Shuo Cao , He Gao , Zong-Hong Zhu

In this paper, we consider the impact of Lorentz Invariance Violation (LIV) on the $\gamma-\gamma$ opacity of the Universe to VHE-gamma rays, compared to the effect of local under-densities (voids) of the Extragalactic Background Light, and…

High Energy Astrophysical Phenomena · Physics 2018-10-09 Hassan Abdalla , Markus Boettcher

We investigate the effects of Lorentz invariance violation (LIV) on photon interactions, considering both intergalactic propagation (Breit-Wheeler process) and atmospheric interactions (Bethe-Heitler process). By incorporating LIV into the…

High Energy Astrophysical Phenomena · Physics 2025-09-19 Denise Boncioli , Valdir Barbosa Bezerra , Matteo Giammarco , Iarley Pereira Lobo , Pedro Morais , Francesco Salamida

Evidence on the violation of Lorentz symmetry arises from the observation of cosmic rays with energies beyond the GZK cutoff, $E_{GZK} \simeq 4 \times 10^{19} eV$, from the apparent transparency of the Universe to the propagation of high…

High Energy Physics - Phenomenology · Physics 2015-06-25 Orfeu Bertolami

Lorentz Invariance Violation introduced as a generic modification to particle dispersion relations is used to study high energy cosmic ray attenuation processes. It is shown to reproduce the same physical effects for vacuum Cherenkov…

High Energy Astrophysical Phenomena · Physics 2017-03-09 H. Martínez-Huerta , A. Pérez-Lorenzana

In this work, we use Lorentz invariance violation (LIV) introduced as a generic modification to particle dispersion relations to study some consequences of single photon emission, known as vacuum Cherenkov radiation, and photon decay…

High Energy Astrophysical Phenomena · Physics 2017-09-27 H. Martínez-Huerta , A. Pérez-Lorenzana

Lorentz invariance violation (LIV) introduced as a generic modification to particle dispersion relations can change the photon energy threshold of pair-production, which modifies the expected gamma-ray flux from astrophysical sources. In…

High Energy Astrophysical Phenomena · Physics 2019-01-11 Humberto Martínez-Huerta , Rodrigo G. Lang , Vitor de Souza

Since the early reports of events beyond the Greisen-Zatsepin-Kuzmin (GZK) cutoff, the investigation of ultrahigh-energy cosmic rays has emerged as a fundamental method for testing Lorentz Invariance violation (LV) effects. Recent advances…

High Energy Astrophysical Phenomena · Physics 2025-03-06 Ping He , Bo-Qiang Ma

In this contribution, our efforts consist in presenting and discussing the status of a paper in progress we are working on to investigate how non-linear electromagnetic effects couple to the parameters that signal Lorentz-symmetry violation…

High Energy Physics - Phenomenology · Physics 2022-07-13 P. Gaete , J. A. Helayël-Neto

Recent work has shown that dispersion relations with Planck scale Lorentz violation can produce observable effects at energies many orders of magnitude below the Planck energy M. This opens a window on physics that may reveal quantum…

High Energy Physics - Phenomenology · Physics 2009-11-07 T. Jacobson , S. Liberati , D. Mattingly

Some Quantum Gravity (QG) theories allow for a violation of Lorentz invariance (LIV), manifesting as a dependence of the velocity of light in vacuum on its energy. If such a dependence exists, then photons of different energies emitted…

The efforts in this contribution consist in reassessing a modified Dirac equation that incorporates a $\gamma^0 \gamma_5$-Lorentz-symmetry violating (LSV) term induced as a Loop Quantum Gravity (LQG) effect. Originally, this equation has…

High Energy Physics - Theory · Physics 2024-09-19 João Paulo S. Melo , Mario J. Neves , Jefferson M. A. Paixão , José A. Helayël-Neto

The tiny modification of dispersion relation induced by Lorentz violation (LV) is an essential issue in quantum gravity (QG) theories, which can be magnified into significant effects when dealing with astrophysical observations at high…

High Energy Astrophysical Phenomena · Physics 2021-10-01 Liang Chen , Zheng Xiong , Cong Li , SongZhan Chen , HuiHai He

Present models describing the interaction of quantum Maxwell and gravitational fields predict a breakdown of Lorentz invariance and a non standard dispersion relation in the semiclassical approximation. Comparison with observational data…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Reinaldo J. Gleiser , Carlos N. Kozameh , Florencia Parisi

Modified dispersion relations(MDRs) as a manifestation of Lorentz invariance violation, have been appeared in alternative approaches to quantum gravity problem. Loop quantum gravity is one of these approaches which evidently requires…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Kourosh Nozari , S. Davood Sadatian

Lorentz violation (LV) is predicted by some quantum gravity theories, where photon dispersion relation is modified, and the speed of light becomes energy-dependent. Consequently, it results in a tiny time delay between high energy photons…

High Energy Physics - Phenomenology · Physics 2010-05-28 Lijing Shao , Zhi Xiao , Bo-Qiang Ma
‹ Prev 1 2 3 10 Next ›