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Related papers: The anomaly in the cosmic-ray positron spectrum

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The AMS experiment onboard the International Space Station has recently provided cosmic ray electron and positron data with unprecedented precision in the range from 0.5 to 350 GeV. The observed rise in the positron fraction at energies…

High Energy Astrophysical Phenomena · Physics 2013-10-29 Lars Bergstrom , Torsten Bringmann , Ilias Cholis , Dan Hooper , Christoph Weniger

Recent observations by the PAMELA and AMS-02 telescopes have uncovered an anomalous rise in the positron fraction at energies above 10~GeV. One possible explanation for this excess is the production of primary electron/positron pairs…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Tim Linden

Cosmic rays at the Earth include a secondary component originating in collisions of primary particles with the diffuse interstellar gas. The secondary cosmic rays are relatively rare but carry important information on the Galactic…

I discuss whether the standard cosmological models fit the WMAP data well enough to justify parameter estimation with standard assumptions. The observed quadrupole is low (but has significant foreground uncertainty) and drives weak evidence…

Astrophysics · Physics 2017-08-23 Antony Lewis

We analyze the data of low-energy cosmic-ray antiproton spectrum, recently published by the BESS Collaboration, in terms of newly calculated fluxes for secondary antiprotons and for a possible contribution of an exotic signal due to…

Astrophysics · Physics 2010-11-30 A. Bottino , F. Donato , N. Fornengo , P. Salati

Using cosmic-ray boron to carbon ratio (B/C) data recently released by the AMS-02 experiment, we find tantalizing indications ({\it decisive evidence}, in Bayesian terms) in favor of a diffusive origin for the broken power-law spectra found…

Recent results by space borne experiments took cosmic ray data to a precision level. These new results are able to challenge the conventional scenario for cosmic ray acceleration and propagation in the Milky Way. In these contributions,…

High Energy Astrophysical Phenomena · Physics 2018-08-23 Manuela Vecchi

The recent observations of the positron fraction in cosmic rays by PAMELA indicate that the fraction of positrons to the total electronic component in cosmic rays initially decreases in the energy region 1-10 GeV and increases thereafter.…

Cosmology and Nongalactic Astrophysics · Physics 2009-06-11 R. Cowsik , B. Burch

Polarization induced by cosmological scalar perturbations leads to a typical anisotropy pattern, which can best be analyzed in Fourier domain. This allows one to unambiguously distinguish cosmological signal of polarization from other…

Astrophysics · Physics 2009-10-28 Uros Seljak

The overabundance of high-energy cosmic positrons, observed by PAMELA and AMS-02, can be considered as the consequence of dark matter decays or annihilations. We show that recent FERMI/LAT measurements of the isotropic diffuse gamma-ray…

High Energy Astrophysical Phenomena · Physics 2016-07-11 Maxim Laletin

The first observations of the cosmic microwave background (CMB) from NASA's \emph{Wilkinson Microwave Anisotropy Probe} (WMAP) led to finding `alignment' anomalies not expected from fluctuations in the isotropic cosmological model. We study…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-03 Sanjeet Kumar Patel , Pavan Kumar Aluri , John P. Ralston

We use absolutely calibrated data between 3 and 90 GHz from the 2006 balloon flight of the ARCADE 2 instrument, along with previous measurements at other frequencies, to constrain models of extragalactic emission. Such emission is a…

Cosmology and Nongalactic Astrophysics · Physics 2009-01-21 M. Seiffert , D. J. Fixsen , A. Kogut , S. M. Levin , M. Limon , P. M. Lubin , P. Mirel , J. Singal , T. Villela , E. Wollack , C. A. Wuensche

Angular anisotropy techniques for cosmic diffuse radiation maps are powerful probes, even for quite small data sets. A popular observable is the angular power spectrum; we present a detailed study applicable to any unbinned source skymap…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Sheldon S. Campbell

The rise in the cosmic-ray positron fraction measured by the PAMELA satellite is likely due to the presence of astrophysical sources of positrons, e.g. pulsars, on the kpc scale around the Earth. Nevertheless, assessing the properties of…

High Energy Astrophysical Phenomena · Physics 2011-07-19 Julien Lavalle

Context: The relation between Galactic cosmic-ray electrons, magnetic fields and synchrotron radiation. Aims: We exploit synchrotron radiation to constrain the low-energy interstellar electron spectrum, using various radio surveys and…

High Energy Astrophysical Phenomena · Physics 2011-10-03 A. W. Strong , E. Orlando , T. R. Jaffe

Recent measurements of the Cosmic Microwave Background Anisotropy have provided evidence for the presence of oscillations in the angular power spectrum. These oscillations are a wonderful confirmation of the standard cosmological scenario…

Astrophysics · Physics 2007-05-23 Alessandro Melchiorri

The results of many experiments on a search of fractionally charged particles in cosmic rays have been reviewed. The registered by ATIC and PAMELA experiments change of the proton energy spectrum at about 250 GeV can be explained if…

High Energy Astrophysical Phenomena · Physics 2016-01-18 George Bashindzhagyan , Natalia Korotkova

The recent Planck data on the power spectrum of temperature anisotropies of the cosmic microwave background marginally support deviations from the $\Lambda$CDM model at several multipoles. With a view towards current and forthcoming…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-27 Spyros Sypsas

This paper presents an introduction to the astrophysics of cosmic rays and diffuse gamma rays and discusses some of the puzzles that have emerged recently due to more precise data and improved propagation models: the excesses in Galactic…

Astrophysics · Physics 2008-11-26 I. V. Moskalenko