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The Universe's early thermal history is poorly constrained, and it is possible that it underwent a period of early matter domination driven by a heavy particle or an oscillating scalar field that decayed into radiation before the onset of…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-06 M. Sten Delos , Tim Linden , Adrienne L. Erickcek

We study the equilibrium structures of white dwarfs with dark matter cores formed by non-self-annihilating dark matter DM particles with mass ranging from 1 GeV to 100 GeV, which are assumed to form an ideal degenerate Fermi gas inside the…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-18 S. -C. Leung , M. -C. Chu , L. -M. Lin , K. -W. Wong

Warm Dark Matter (WDM) models have recently been resurrected to resolve apparent conflicts of Cold Dark Matter (DM) models with observations. Endowing the DM particles with non-negligible velocities causes free-streaming, which suppresses…

Astrophysics · Physics 2009-11-06 Zoltan Haiman , Rennan Barkana , Jeremiah P. Ostriker

An ultra-light bosonic particle of mass around $10^{-22}\,\mathrm{eV}/c^2$ is of special interest as a dark matter candidate, as it both has particle physics motivations, and may give rise to notable differences in the structures on highly…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-18 Simon May , Volker Springel

A huge amount of good quality astrophysical data converges towards the picture of a spatially flat universe undergoing the today observed phase of accelerated expansion. This new observational trend is commonly addressed as Precision…

Astrophysics · Physics 2009-06-23 S. Capozziello

Elucidating the particle physics nature of dark matter (DM) is one of the great challenges in modern science. The current lack of any direct DM detections in the laboratory heightens the need for astrophysical constraints, extending the…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-07 James M. Sullivan , Shingo Hirano , Volker Bromm

Gravitational positivity bounds provide consistency conditions for effective field theories with gravity. They turn out to be phenomenologically useful by providing lower bounds in parameters of new physics beyond the Standard Models (BSM).…

High Energy Physics - Phenomenology · Physics 2025-01-24 Suro Kim , Pyungwon Ko

We consider a cosmological model in which a fraction $f$ of the Dark Matter (DM) is allowed to decay in an invisible relativistic component, and compute the resulting constraints on both the decay width (or inverse lifetime) $\Gamma$ and…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-31 Vivian Poulin , Pasquale D. Serpico , Julien Lesgourgues

Light dark photons are subject to various plasma effects, such as Debye screening and resonant oscillations, which can lead to a more complex cosmological evolution than is experienced by conventional cold dark matter candidates.…

High Energy Physics - Phenomenology · Physics 2020-04-01 Samuel D. McDermott , Samuel J. Witte

Many independent high resolution simulations have indicated that the standard collisionless cold dark matter model does not reproduce the structure of observed present day galaxies well. Several possible solutions in the form of…

Astrophysics · Physics 2007-05-23 Steen Hannestad

The Galactic dwarf spheroidal galaxies (dSphs) provide valuable insight into dark matter (DM) properties and its role in galaxy formation. Their close proximity enables the measurement of line-of-sight velocities for resolved stars, which…

In some scenarios for the early universe, non-relativistic thermal dark matter chemically decouples from the thermal environment once the temperature drops well below the dark matter mass. The value at which the energy density freezes out…

High Energy Physics - Phenomenology · Physics 2025-01-09 Simone Biondini , Nora Brambilla , Andrii Dashko , Gramos Qerimi , Antonio Vairo

It is well-known that Einstein's equations constrain only the total energy-momentum tensor of the cosmic substratum, without specifying the characteristics of its individual constituents. Consequently, cosmological models featuring distinct…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-20 Dinorah Barbosa , Rodrigo von Marttens , Javier Gonzalez , Jailson Alcaniz

The negative pressure accompanying gravitationally-induced particle creation can lead to a cold dark matter (CDM) dominated, accelerating Universe (Lima et al. 1996) without requiring the presence of dark energy or a cosmological constant.…

Astrophysics · Physics 2009-07-22 G. Steigman , R. C. Santos , J. A. S. Lima

Dark matter (DM) could be a relic of freeze-in through a light mediator, where the DM is produced by extremely feeble, IR-dominated processes in the thermal Standard Model plasma. In the simplest viable models with the DM mass below the MeV…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-15 Cora Dvorkin , Tongyan Lin , Katelin Schutz

Quantum degeneracy pressure (QDP) underscores the stability of matter and is arguably the most ubiquitous many-body effect. The associated Fermi surface (FS) has broad implications for physical phenomena, ranging from electromagnetic…

Strongly Correlated Electrons · Physics 2020-08-26 Sen Mu , Ching Hua Lee , Linhu Li , Jiangbin Gong

If dark matter (DM) has non-zero direct or transition, electric or magnetic dipole moment then it can scatter nucleons electromagnetically in direct detection experiments. Using the results from experiments like XENON, CDMS, DAMA and COGENT…

High Energy Physics - Phenomenology · Physics 2009-09-02 Eduard Masso , Subhendra Mohanty , Soumya Rao

In this work we consider how the appearance of gradients of pseudoscalar condensates in dense systems may possibly influence the transport properties of photons in such a medium as well as other thermodynamic characteristics. We adopt the…

High Energy Physics - Phenomenology · Physics 2016-04-20 A. A. Andrianov , V. A. Andrianov , D. Espriu , S. S. Kolevatov

We present a model independent analysis of dark matter (DM) both decoupling ultra relativistic (UR) and non-relativistic (NR) based in the phase-space density D = rho_{DM}/sigma^3_{DM}. We derive explicit formulas for the DM particle mass m…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-07 H. J. de Vega , N. G. Sanchez

In the cold dark matter scenario, galactic dark matter halos are populated with a large number of smaller subhalos. Previous work has shown that dark matter annihilations in subhalos can generate a distinctive, non-Poisson signal in the…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-24 Jack Runburg , Eric J. Baxter , Jason Kumar