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Related papers: The origin of the ankle

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The origin of the accelerated expansion of the universe is still unclear and new physics is needed on cosmological scales. We propose and test a novel interpretation of dark energy as originated by an elastic strain due to a cosmic defect…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 N. Radicella , M. Sereno , A. Tartaglia

Supernova remnants have long been regarded as sources of the Galactic cosmic rays up to petaelectronvolts, but convincing evidence is still lacking. In this work we explore the common origin of the subtle features of the cosmic ray spectra,…

High Energy Astrophysical Phenomena · Physics 2009-07-17 Hong-Bo Hu , Qiang Yuan , Bo Wang , Chao Fan , Jian-Li Zhang , Xiao-Jun Bi

We fit the HiRes ultra-high energy cosmic ray (UHECR) spectrum measurements with broken power laws in order to identify features. These fits find the previously observed feature known as the Ankle at 10**18.5 eV, as well as evidence for a…

Astrophysics · Physics 2019-08-14 D. R. Bergman

We explore the possibility that a new physics interaction can provide an explanation for the knee just above $10^6$ GeV in the cosmic ray spectrum. We model the new physics modifications to the total proton-proton cross section with an…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-19 Aparna Dixit , Pankaj Jain , Douglas W. McKay , Parama Mukherjee

It is shown that the fine stucture of the cosmic ray energy spectrum in the knee region, if explained by the Single Source Model (SSM), can, in principle, be clearly revealed and magnified in the size spectrum of extensive air showers (EAS)…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. D. Erlykin , A. W. Wolfendale

We re-examine the interaction of ultra high energy nuclei with the microwave background radiation. We find that the giant dipole resonance leaves a new signature in the differential energy spectrum of iron sources located around 3 Mpc: A…

Astrophysics · Physics 2009-10-30 L. A. Anchordoqui , M. T. Dova , L. N. Epele , J. D. Swain

At present, there is no consensus on whether the spectral break in the cosmic-ray flux of all elements around 4 PeV is a general characteristic of the Milky Way or is determined by a combination of factors that significantly affect the…

High Energy Astrophysical Phenomena · Physics 2025-07-11 Vladislav Borisov , Vladimir Yurovsky , Alexandra Peryatinskaya , Ilya Kudryashov

Ultra-high-energy cosmic rays (UHECRs) are the most energetic particles known - and yet their origin is still an open question. However, with the precision and accumulated statistics of the Pierre Auger Observatory and the Telescope Array,…

High Energy Astrophysical Phenomena · Physics 2025-11-10 Teresa Bister

The energy spectrum of cosmic rays (CR) exhibits power-like behavior with a very characteristic "knee" structure. We consider a possibility that such a spectrum could be generated by some specific nonstatistical temperature fluctuations in…

High Energy Physics - Phenomenology · Physics 2011-11-28 Grzegorz Wilk , Zbigniew Wlodarczyk

The energy spectrum of cosmic rays in the range 10^15 eV to 6*10^19 eV has been studied using the air Cherenkov light detectors of the Yakutsk array. The total flux of photons produced by relativistic electrons (including positrons as well,…

High Energy Astrophysical Phenomena · Physics 2009-08-05 A. A. Ivanov , S. P. Knurenko , I. Ye. Sleptsov

We suggest a physical mechanism whereby the acceleration time of cosmic rays by shock waves can be significantly reduced. This creates the possibility of particle acceleration beyond the knee energy at ~10^15eV. The acceleration results…

Astrophysics · Physics 2009-11-13 M. A. Malkov , P. H. Diamond

The knee phenomenon of the cosmic ray spectrum, which plays an important role in studying the acceleration mechanism of cosmic rays, is still an unsolved mystery. We try to reconcile the knee spectra measured by ARGO-YBJ and Tibet-III. A…

High Energy Astrophysical Phenomena · Physics 2015-10-22 Yi Zhao , Huan-Yu Jia , Feng-Rong Zhu

A new strong-interaction has been postulated for neutrinos above ~10^{19} eV to explain the production of highest-energy cosmic ray events. We derive a dispersion relation relating the hypothesized high-energy cross-section to the…

High Energy Physics - Phenomenology · Physics 2016-09-06 Haim Goldberg , T. J. Weiler

Stellar limb darkening is the observed variation in brightness of a star between its centre and edge (or limb) when viewed in the plane of the sky. Stellar brightness is maximal at the centre and then decreases radially and monotonically…

Instrumentation and Methods for Astrophysics · Physics 2024-08-21 David Grant , Hannah R. Wakeford

The energy spectrum, composition and arrival directions of ultrahigh energy cosmic rays (UHECRs) with energy above the cosmic ray ankle, measured by the Pierre Auger Observatory, are inconsistent if their origin is assumed to be…

High Energy Astrophysical Phenomena · Physics 2012-02-07 Shlomo Dado , Arnon Dar , A. De Rujula

Recent measurements revealed the presence of several features in the cosmic ray spectrum. In particular, the proton and helium spectra exhibit a spectral hardening at $\approx$ 300 GV and a spectral steeping at $\approx$ 15 TV, followed by…

High Energy Astrophysical Phenomena · Physics 2024-12-04 Sarah Recchia , Stefano Gabici

The energy spectrum of the primary cosmic radiation in the energy range 1 - 100 PeV and the extensive air shower (EAS) characteristics obtained on the basis of the expanded data bank of the GAMMA experiment (Mt. Aragats, Armenia) are…

High Energy Astrophysical Phenomena · Physics 2015-06-03 R. M. Martirosov , A. P. Garyaka , H. S. Vardanyan , A. D. Erlykin , N. M. Nikolskaya , Y. A. Gallant , L. W. Jones , H. A. Babayan

In the last few years several experiments have shown that the cosmic ray spectrum below the knee is not a perfect power-law. In particular, the proton and helium spectra show a spectral hardening by ~ 0.1-0.2 in spectral index at particle…

High Energy Astrophysical Phenomena · Physics 2017-12-27 S. Recchia , S. Gabici

Examples of the power law spectra observations in the Nature are given. It is shown that the observed meteoroid mass spectrum is very similar to the observed cosmic ray energy spectrum. It is concluded that the "knees" observed in both…

Astrophysics · Physics 2007-05-23 Yuri V. Stenkin

In the Coulomb field of nucleus cut off on it size, besides usual atomic states, there are additional ones. These anomalous states are deep (in the range of $10\,MeV$) in the Dirac sea and can exist solely during a macroscopic acceleration…

General Physics · Physics 2024-01-18 B. Ivlev
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