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Observations of cosmic rays are a sensitive probe of dark matter annihilation in our Galaxy. In this article we present an analysis of the AMS-02 antiproton data, reducing cosmic-ray propagation uncertainties by fitting at the same time…

High Energy Astrophysical Phenomena · Physics 2018-04-23 Alessandro Cuoco , Jan Heisig , Michael Korsmeier , Michael Krämer

Galaxy clusters are dominated by dark matter, and may have a larger proportion of surviving substructure than, e.g, field galaxies. Due to the presence of galaxy clusters in relative proximity and their high dark matter content, they are…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-01 Douglas Quincy Adams , Lars Bergstrom , Douglas Spolyar

For the first time, the Fermi-LAT measured the angular power spectrum (APS) of anisotropies in the diffuse gamma-ray background. The data is found to be broadly compatible with a model with contributions from the point sources in the 1-year…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Mattia Fornasa , Jesus Zavala , Miguel A. Sanchez-Conde , Francisco Prada , Mark Vogelsberger

Dark matter (DM) annihilations have been widely studied as a possible explanation of excess gamma rays from the galactic center seen by Fermi/LAT. However most such models are in conflict with constraints from dwarf spheroidals. Motivated…

High Energy Physics - Phenomenology · Physics 2016-07-22 Jeremie Choquette , James M. Cline , Jonathan M. Cornell

Employing Fermi-LAT gamma ray observations, several independent groups have found excess extended gamma ray emission at the Galactic center (GC). Both, annihilating dark matter (DM) or a population of $\sim 10^3$ unresolved millisecond…

High Energy Astrophysical Phenomena · Physics 2013-12-12 Chris Gordon , Oscar Macias

Annihilating dark matter particles in nearby subhalos could generate potentially observable fluxes of gamma rays, unaccompanied by emission at other wavelengths. Furthermore, this gamma-ray emission is expected to be spatially extended,…

High Energy Physics - Phenomenology · Physics 2017-09-26 Ti-Lin Chou , Dimitrios Tanoglidis , Dan Hooper

The region around the Galactic center (GC) is now well established to be brighter at energies of a few GeV than expected from conventional models of diffuse gamma-ray emission and catalogs of known gamma-ray sources. We study the GeV excess…

High Energy Astrophysical Phenomena · Physics 2017-06-27 LAT Collaboration

Utilizing data from the ELVIS and Via Lactea-II simulations, we characterize the local dark matter subhalo population, and use this information to refine the predictions for the gamma-ray fluxes arising from annihilating dark matter in this…

High Energy Astrophysical Phenomena · Physics 2017-04-19 Dan Hooper , Samuel J. Witte

We examine the possibility that the dark matter (DM) interpretation of the GeV scale Fermi gamma-ray excess at the Galactic Center can be realized in a specific framework - secluded singlet fermionic dark matter model with small mixing…

High Energy Physics - Phenomenology · Physics 2016-06-29 Yeong Gyun Kim , Kang Young Lee , Chan Beom Park , Seodong Shin

We analyze the cosmic-ray signatures of decaying gravitino dark matter in a model independent way based on an operator analysis. Thermal leptogenesis and universal boundary conditions at the GUT scale restrict the gravitino mass to be below…

High Energy Physics - Phenomenology · Physics 2009-09-16 Wilfried Buchmüller , Alejandro Ibarra , Tetsuo Shindou , Fumihiro Takayama , David Tran

The apparent excess of gamma rays in an extended region in the direction of the galactic center has a spatial distribution and amplitude that are suggestive of dark matter annihilations. If this excess is indeed due to dark matter…

High Energy Physics - Phenomenology · Physics 2014-11-19 Adam Martin , Jessie Shelton , James Unwin

PAMELA's observation that the cosmic ray positron fraction increases rapidly with energy implies the presence of primary sources of energetic electron-positron pairs. Of particular interest is the possibility that dark matter annihilations…

High Energy Physics - Phenomenology · Physics 2014-11-20 Dan Hooper , Kathryn M. Zurek

Dwarf galaxies represent a powerful probe of annihilating dark matter particle models, with gamma-ray data setting some of the best bounds available. A major issue in improving over existing constraints consists in the limited knowledge of…

High Energy Astrophysical Phenomena · Physics 2018-11-14 Francesca Calore , Pasquale D. Serpico , Bryan Zaldivar

We provide conservative bounds on the dark matter cross-section and lifetime from final state radiation produced by annihilation or decay into charged leptons, either directly or via an intermediate particle $\phi$. Our analysis utilizes…

High Energy Physics - Phenomenology · Physics 2009-09-04 Rouven Essig , Neelima Sehgal , Louis E. Strigari

A number of papers attempt to explain the positron anomaly in cosmic rays, observed by PAMELA and AMS-02, in terms of dark matter (DM) decays or annihilations. However, the recent progress in cosmic gamma-ray studies challenges these…

High Energy Astrophysical Phenomena · Physics 2017-01-12 Konstantin Belotsky , Ruslan Budaev , Alexander Kirillov , Maxim Laletin

We determine upper limits on the dark matter (DM) self-annihilation cross section for scenarios in which annihilation leads to the production of electron--positron pairs. In the Galactic centre (GC), relativistic electrons and positrons…

High Energy Physics - Phenomenology · Physics 2014-11-20 Roland M. Crocker , Nicole F. Bell , Csaba Balázs , David I. Jones

The bulk of the extragalactic background between 10 keV and 10 GeV is likely to be explained by the emission of Seyfert galaxies, type Ia supernovae, and blazars. However, as revealed by the INTEGRAL satellite, the bulge of our galaxy is an…

A number of theories, spanning a wide range of mass scales, predict dark matter candidates that have lifetimes much longer than the age of the universe, yet may produce a significant flux of gamma rays in their decays today. We constrain…

Astrophysics · Physics 2008-11-26 Hasan Yuksel , Matthew D. Kistler

The contribution of unresolved sources to the diffuse gamma-ray background could produce anisotropies in this emission on small angular scales. Recent studies have considered the angular power spectrum and other anisotropy metrics as tools…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Jennifer M. Siegal-Gaskins

Annihilating dark matter particles produce roughly as much power in electrons and positrons as in gamma ray photons. The charged particles lose essentially all of their energy to inverse Compton and synchrotron processes in the galactic…

Astrophysics · Physics 2009-11-10 E. A. Baltz , L. Wai