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Related papers: Axion effects on gamma-ray spectral irregularities…

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Prompted by the increasing interest of axion-like particles (ALPs) for very-high-energy (VHE) astrophysics, we have considered a full scenario for the propagation of a VHE photon/ALP beam emitted by a BL Lac and reaching us in the light of…

High Energy Astrophysical Phenomena · Physics 2019-05-02 Giorgio Galanti , Fabrizio Tavecchio , Marco Roncadelli , Carmelo Evoli

An intriguing possibility to partially circumvent extragalactic background light (EBL) absorption in very-high-energy (VHE) observations of blazars is that photons convert into axion-like particles (ALPs) $\gamma \to a$ inside or close to a…

High Energy Astrophysical Phenomena · Physics 2014-09-11 F. Tavecchio , G. Galanti , M. Roncadelli

The LHAASO collaboration recently reported the measurement of the gamma-ray spectra of GRB 221009A, which is the brightest burst ever, covering an energy range from 0.3 $\mathrm{TeV}$ to about 10 $\mathrm{TeV}$. Based on the observation, we…

High Energy Astrophysical Phenomena · Physics 2024-01-17 Lin-Qing Gao , Xiao-Jun Bi , Jun Li , Run-Min Yao , Peng-Fei Yin

The CIBER collaboration released their first observational data of the Cosmic IR background (CIB) radiation, which has significant excesses at around the wavelength $\sim$ 1 $\mu$m compared to theoretically-inferred values. The amount of…

High Energy Physics - Phenomenology · Physics 2017-10-04 Kazunori Kohri , Hideo Kodama

The Extragalactic Background Light (EBL) includes photons with wavelengths from ultraviolet to infrared, which are effective at attenuating gamma rays with energy above ~10 GeV during propagation from sources at cosmological distances. This…

High Energy Astrophysical Phenomena · Physics 2015-05-18 The Fermi LAT , the GBM Collaboration , : , A. A. Abdo

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

We study photon-ALP conversion by resonance effects in the magnetized plasma of galaxy clusters and compare the predicted distortion of the cosmic microwave background spectrum in the direction of such objects to measurements of the thermal…

High Energy Physics - Phenomenology · Physics 2016-02-05 Martin Schlederer , Günter Sigl

The propagation of TeV gamma rays can be strongly modified by B-field induced conversion to axionlike particles (ALPs). We show that, at such high energies, photon dispersion is dominated by background photons - the only example where…

High Energy Astrophysical Phenomena · Physics 2017-06-07 Alexandra Dobrynina , Alexander Kartavtsev , Georg Raffelt

Axion-like particles (ALPs) are hypothetical pseudoscalar bosons, natural in extensions of the Standard Model. Their interactions with ordinary matter and radiation are suppressed, making it challenging to detect them in laboratory…

High Energy Physics - Phenomenology · Physics 2025-03-27 S. V. Troitsky

High-energy neutrino observation from the Seyfert galaxy NGC 1068 offers new insights into the non-thermal processes of active galactic nuclei. Simultaneous gamma-rays emitted by such sources can possibly oscillate into axion-like particles…

High Energy Physics - Phenomenology · Physics 2025-06-18 Ariane Dekker , Gonzalo Herrera , Dimitrios Kantzas

Axions or axion-like particles (ALPs) are well-motivated dark matter (DM) candidates whose coupling to photons induces periodic oscillations in the polarization angle of astrophysical light. This work reports the first search for such a…

High Energy Astrophysical Phenomena · Physics 2025-11-11 Qiu-Ju Huang , Bao Wang , Jun-Jie Wei , Xue-Feng Wu

We perform a linear mode analysis of a uniformly distributed cloud of axion-like particles (ALPs) embedded in a magnetized intergalactic medium, in order to investigate the stability of axion stars under realistic astrophysical conditions.…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-14 Kuldeep J. Purohit , Jitesh R. Bhatt , Subhendra Mohanty , Prashant K. Mehta

Pseudoscalar particles like axion-like particles generically couple to two photons, giving rise to the possibility of oscillations with photons in an external magnetic field. These oscillations could lead to measurable imprints in the…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Denis Wouters , Pierre Brun

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

Axions or axion-like particles (ALPs) are one of the promising dark matter (DM) candidates. A prevalent method to detect axion-like DM is to seek periodic oscillation in the polarization angles (PAs) of linearly polarized light emitted from…

High Energy Astrophysical Phenomena · Physics 2025-04-03 Bao Wang , Xuan Yang , Jun-Jie Wei , Song-Bo Zhang , Xue-Feng Wu

Axion-like particles (ALPs), which are very light neutral spin zero elusive particles primarily interacting with two photons and predicted by superstring and superbrane theories, have come to help by solving two distinct problems about…

High Energy Astrophysical Phenomena · Physics 2023-01-20 Giorgio Galanti , Marco Roncadelli , Fabrizio Tavecchio

We use the first observation of Betelgeuse in hard $X$-rays to perform a novel search for axion-like particles (ALPs). Betelgeuse is not expected to be a standard source of $X$-rays, but light ALPs produced in the stellar core could be…

Axion-like particles (ALPs) can be produced by thermal processes in a stellar interior, escape from the star and, if sufficiently light, be converted into photons in the external Galactic magnetic field. Such a process could produce a…

High Energy Astrophysical Phenomena · Physics 2022-12-27 Mengjiao Xiao , Pierluca Carenza , Maurizio Giannotti , Alessandro Mirizzi , Kerstin M. Perez , Oscar Straniero , Brian W. Grefenstette

The extragalactic background light is comprised of the cumulative radiation from all galaxies across the history of the universe. The angular power spectrum of the anisotropies of such a background at near-infrared (IR) frequencies lacks of…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-20 Andrea Caputo , Andrea Vittino , Nicolao Fornengo , Marco Regis , Marco Taoso