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Related papers: Photon-ALP conversions inside AGN

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Axion-like particles (ALPs) are a broad class of pseudo-scalar bosons that generically arise from broken symmetries in extensions of the standard model. In many scenarios, ALPs can mix with photons in regions with high magnetic fields.…

High Energy Physics - Phenomenology · Physics 2022-03-10 Sunniva Jacobsen , Tim Linden , Katherine Freese

Magnetic fields in extragalactic space between galaxy clusters may induce conversions between photons and axion-like particles (ALPs), thereby shielding the photons from absorption on the extragalactic background light. For TeV gamma rays,…

High Energy Astrophysical Phenomena · Physics 2017-01-13 A. Kartavtsev , G. Raffelt , H. Vogel

We re-derive the possible dependence of the redshift with very high energy (VHE) $\gamma$-ray photon index. The results suggest that the universe to VHE $\gamma$-rays is becoming more transparent than usually expected. We introduce the…

High Energy Astrophysical Phenomena · Physics 2023-08-02 L. J. Dong , Y. G. Zheng , S. J. Kang

Axion-like particles (ALPs) are a common prediction of certain theories beyond the Standard Model and couple to photons in the presence of external magnetic fields. As a consequence, photon-ALP conversions could lead to an enhancement of…

High Energy Astrophysical Phenomena · Physics 2014-12-09 Manuel Meyer

In the presence of a background magnetic field, axions or axion-like particles (ALPs) can be resonantly converted to photons when their mass is nearly equal to the effective photon mass. In this paper, we propose a novel method to constrain…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-21 Ashu Kushwaha , Rajeev Kumar Jain

Axion-like particles (ALPs), hypothetical extensions of the Standard Model, can convert into photons in an external magnetic field. Two recent studies~\cite{Todarello:2023ptf, Ruz:2024gkl} explored the phenomenology of ALP-photon conversion…

High Energy Physics - Phenomenology · Physics 2025-01-28 Elisa Todarello

In this paper we outline an experiment to detect the conversion of photons to axion-like particles (ALPs) in a strong magnetic field. We show that by modulating the polarization of the light passing through a Fabry-Perot cavity so that it…

High Energy Physics - Phenomenology · Physics 2022-04-13 Richard Creswick , Frank T. Avignone

Very high energy (VHE, energy >~ 100 GeV) {\gamma}-rays originating from extragalactic sources interact with low energy photons of background radiation fields and produce electron-positron pairs. Alternatively, in the presence of ambient…

High Energy Astrophysical Phenomena · Physics 2012-11-28 Manuel Meyer , Dieter Horns , Luca Maccione , Alessandro Mirizzi , Daniele Montanino , Marco Roncadelli

Several extensions of the Standard Model predict the existence of Axion-Like Particles (ALPs), very light spin-zero bosons with a two-photon coupling. ALPs can give rise to observable effects in very-high-energy astrophysics. Above roughly…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Marco Roncadelli , Alessandro De Angelis , Giorgio Galanti

Axion-like particles (ALPs) are hypothetical entities often invoked to solve various problems in particle physics to cosmology. They are one of the most promising candidates to explain the elusive dark matter. A way to search for ALPs is…

High Energy Physics - Phenomenology · Physics 2023-08-29 Rafael Alves Batista , Cristina Viviente , Gaetano Di Marco , Miguel A. Sánchez-Conde

A fraction of AGN producing VHE gamma-rays are located in galaxy clusters. The magnetic field present in the intra-cluster medium would lead to conversions of VHE photons into axion-like particles (ALPs), which are a generic prediction of…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Dieter Horns , Luca Maccione , Manuel Meyer , Alessandro Mirizzi , Daniele Montanino , Marco Roncadelli

We study magnetic conversion of ultra-relativistic axion-like particles (ALPs) into photons in compact-star environments, focusing on the hot, transient conditions of core-collapse supernova (SN) remnants and neutron-star mergers (NSMs). We…

High Energy Physics - Phenomenology · Physics 2026-05-06 Damiano F. G. Fiorillo , Ángel Gil Muyor , Hans-Thomas Janka , Georg G. Raffelt , Edoardo Vitagliano

Decaying axion-like particles (ALP) with masses in the eV range which might occupy dark matter halos of the Milky Way and other galaxies produce a characteristic "bump" feature in the spectrum of extragalactic background light (EBL). This…

High Energy Physics - Phenomenology · Physics 2020-04-20 A. Korochkin , A. Neronov , D. Semikoz

Axion-like particles (ALPs) are light, neutral, pseudo-scalar bosons predicted by several extensions of the Standard Model of particle physics -- such as the String Theory -- and are supposed to interact primarily only with two photons. In…

High Energy Astrophysical Phenomena · Physics 2019-11-22 Giorgio Galanti

The very high energy (VHE, E $>$ $100 \mathrm~{GeV}$) $\gamma$-ray observations offer a possibility of indirectly detecting the presence of axion-like particles (ALPs). The paper focuses on detecting photon-ALP oscillations on $\gamma$-ray…

High Energy Astrophysical Phenomena · Physics 2025-03-03 L. J. Dong , Y. G. Zheng , S. J. Kang , C. Y. Yang

Axion-like particles (ALPs) are hypothetical particles and compelling candidates for cold dark matter. Their existence could be probed through their conversions into photons in the presence of magnetic fields. In this work, we explore the…

High energy gamma-rays propagating in external magnetic fields may convert into axion-like particles (ALPs). In this case, the observed gamma-ray spectra are modified by the resulting energy-dependent conversion probability. In this study,…

High Energy Astrophysical Phenomena · Physics 2023-06-13 Qixin Yu , Dieter Horns

Axion Like Particles (ALPs) are predicted to couple with photons in the presence of magnetic fields. This effect may lead to a significant change in the observed spectra of gamma-ray sources such as AGNs. Here we carry out a detailed study…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-31 M. A. Sanchez-Conde , D. Paneque , E. Bloom , F. Prada , A. Dominguez

D. Wouters and P. Brun in Phys. Rev. D 86, 043005 (2012) claim that an observable effect in the spectra of distant very-high-energy blazars arises as a consequence of oscillations of photons into axion-like particles (ALPs) in the presence…

High Energy Astrophysical Phenomena · Physics 2013-06-27 Giorgio Galanti , Marco Roncadelli

Axion-like particles (ALPs), predicted in theories beyond the Standard Model, can have observational effects on the transparency of the Universe to $\gamma$ rays in the presence of magnetic fields. In this work, we search for effects…

High Energy Astrophysical Phenomena · Physics 2020-10-30 Rolf Buehler , Galo Gallardo , Gernot Maier , Alberto Domínguez , Marcos López , Manuel Meyer