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Related papers: Dark Matter Annihilations in the Causal Diamond

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In hidden sector models, dark matter does not directly couple to the particle content of the Standard Model, strongly suppressing rates at direct detection experiments, while still allowing for large signals from annihilation. In this…

High Energy Physics - Phenomenology · Physics 2020-08-25 Dan Hooper , Rebecca K. Leane , Yu-Dai Tsai , Shalma Wegsman , Samuel J. Witte

We propose an alternative scenario for the dark matter generation from an evolving cosmological constant which interacts with the dominant background in certain intermediate phase of the universe, and relaxes to the observed small value at…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-01 Murli Manohar Verma

The direct measurements of the cosmic electron-positron spectrum around 1 TeV made by DAMPE have induced many theoretical speculations about possible excesses in the data above the standard astrophysical predictions that might have the dark…

High Energy Astrophysical Phenomena · Physics 2019-07-01 Konstantin Belotsky , Airat Kamaletdinov , Maxim Laletin , Maxim Solovyov

A novel fractal structure for the cosmological horizon, inspired by COVID-19 geometry, which results in a modified area entropy, is applied to cosmology in order to serve dark energy. The constraints based on a complete set of observational…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-18 Mariusz P. Dabrowski , Vincenzo Salzano

Annihilating dark matter (DM) has been discussed as a possible source of gamma-rays from the galactic center (GC) and contributing to the extragalactic gamma-ray background (EGB). Assuming universality of the density profile of DM halos, we…

Astrophysics · Physics 2007-05-23 Shin'ichiro Ando

The center of the Milky Way is predicted to be the brightest region of gamma-rays generated by self-annihilating dark matter particles. Excess emission about the Galactic center above predictions made for standard astrophysical processes…

High Energy Physics - Phenomenology · Physics 2017-05-10 Christopher Karwin , Simona Murgia , Tim M. P. Tait , Troy A. Porter , Philip Tanedo

The relic abundance of thermal dark matter particles is generally assumed to be inversely proportional to their annihilation rate, which is therefore constrained by the present matter density, <sigma v> ~ 10^{-26} Omega_{dm}^{-1} cm^3…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-07 Leonid Chuzhoy

A period of early matter domination can give rise to the correct dark matter abundance for a broad range of dark matter annihilation rate $\langle \sigma_{\rm ann} v \rangle_{\rm f}$. Here, we examine this scenario for situations where…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-29 Rouzbeh Allahverdi , Koushik Dutta , Anshuman Maharana

In this paper a new theory of Dark Matter is proposed. Experimental analysis of several Galaxies show how the non-gravitational contribution to galactic Velocity Rotation Curves can be interpreted as that due to the Cosmological Constant…

Astrophysics · Physics 2007-05-23 G. V. Kraniotis , S. B. Whitehouse

Decaying or annihilating dark matter particles could be detected through gamma-ray emission from the species they decay or annihilate into. This is usually done by modelling the flux from specific dark matter-rich objects such as the Milky…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-01 Deaglan J. Bartlett , Andrija Kostić , Harry Desmond , Jens Jasche , Guilhem Lavaux

We analyze the annihilation cross section of dark matter which interacts with the standard model sector over the scalar unparticle propagator. We observe that the annihilation cross section of dark matter pair is sensitive to the dark…

High Energy Physics - Phenomenology · Physics 2015-06-05 E. O. Iltan

We study the gamma rays observed by the Fermi Gamma Ray Space Telescope from the direction of the Galactic Center and find that their angular distribution and energy spectrum are well described by a dark matter annihilation scenario. In…

High Energy Physics - Phenomenology · Physics 2009-11-11 Lisa Goodenough , Dan Hooper

A number of groups have employed radio observations of the Galactic center to derive stringent constraints on the annihilation cross section of weakly interacting dark matter. In this paper, we show that electron energy losses in this…

High Energy Astrophysical Phenomena · Physics 2016-02-09 Ilias Cholis , Dan Hooper , Tim Linden

The first stars in the universe form inside $\sim 10^6 M_\odot$ dark matter (DM) haloes whose initial density profiles are laid down by gravitational collapse in hierarchical structure formation scenarios. During the formation of the first…

Astrophysics · Physics 2011-02-11 Katherine Freese , Paolo Gondolo , J. A. Sellwood , Douglas Spolyar

We investigate reversible and irreversible thermodynamic processes in cosmology and their impact on the Hubble tension. Gravitationally induced adiabatic matter creation/annihilation is treated as irreversible, while energy exchange between…

General Relativity and Quantum Cosmology · Physics 2026-03-12 Hussain Gohar

Dark matter (DM) can give observable effects decaying or annihilating with production of electrons or/and photons. Such probability was widely researched for our Galaxy. Here we consider one aspect of similar effect for Andromeda galaxy. We…

High Energy Astrophysical Phenomena · Physics 2020-11-11 K. M. Belotsky , E. S. Shlepkina , M. L. Soloviev

Decaying Dark Energy models modify the background evolution of the most common observables, such as the Hubble function, the luminosity distance and the Cosmic Microwave Background temperature-redshift scaling relation. We use the most…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-05 Ivan de Martino

Using the upper bound on the inelastic reaction cross-section implied by S-matrix unitarity, we derive the thermally averaged maximum dark matter (DM) annihilation rate for general $k \rightarrow 2$ number-changing reactions, with $k \geq…

High Energy Physics - Phenomenology · Physics 2021-03-17 Disha Bhatia , Satyanarayan Mukhopadhyay

Limits on the dark matter fraction of small mass primordial black holes from Hawking radiation are predominantly derived from the assumption of a Schwarzschild black hole evaporating. However, astrophysical black holes are usually much more…

General Relativity and Quantum Cosmology · Physics 2026-04-03 Sebastian Schuster , Jessica Santiago , Justin Feng , Matt Visser

CMSSM boundary conditions are usually used when calculating cosmological dark matter densities. In this paper we calculate the cosmological density of dark matter in the MSSM using minimal $SO_{10}$ soft SUSY breaking boundary conditions.…

High Energy Physics - Phenomenology · Physics 2011-03-23 R. Dermisek , S. Raby , L. Roszkowski , R. Ruiz de Austri