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Related papers: Dissipation of dark matter

200 papers

Numerical hydrodynamic simulation of inviscid and viscous flows have shown that significant outflows could be produced from the CENtrifugal pressure supported BOundary Layer or CENBOL of an advective disk. However, this barrier is weakened…

High Energy Astrophysical Phenomena · Physics 2016-07-19 Shreeram Nagarkoti , Sandip K. Chakrabarti

Matter in the universe has become ``dark'' or ``missing'' through misconceptions about the fluid mechanics of gravitational structure formation. Gravitational condensation occurs on non-acoustic density nuclei at the largest Schwarz length…

Astrophysics · Physics 2007-05-23 Carl H. Gibson

The bulk viscosity of cold, dense three-flavor quark matter is studied as a function of temperature and the amplitude of density oscillations. The study is also extended to the case of two different types of anharmonic oscillations of…

Nuclear Theory · Physics 2015-03-17 Igor A. Shovkovy , Xinyang Wang

We investigate the cosmological perturbation dynamics for a universe consisting of pressureless baryonic matter and a viscous fluid, the latter representing a unified model of the dark sector. In the homogeneous and isotropic background the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-21 W. S. Hipólito-Ricaldi , H. E. S. Velten , W. Zimdahl

We provide a new constraint on the small-scale density fluctuations, evaluating the diffuse background free-free emission from dark matter halos in the dark ages. If there exists a large amplitude of the matter density fluctuations on small…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-12 Katsuya T. Abe , Teppei Minoda , Hiroyuki Tashiro

In the standard cosmological model, dark matter drives the structure formation and constructs potential wells within which galaxies may form. The baryon fraction in dark halos can reach the universal value (15.7%) in massive clusters and…

Astrophysics of Galaxies · Physics 2019-12-05 Qi Guo , Huijie Hu , Zheng Zheng , Shihong Liao , Wei Du , Shude Mao , Linhua Jiang , Jing Wang , Yingjie Peng , Liang Gao , Jie Wang , Hong Wu

We explore the cosmological implications at effective level of matter creation effects in a dissipative fluid for a FLRW geometry; we also perform a statistical analysis for this kind of model. By considering an inhomogeneous Ansatz for the…

General Relativity and Quantum Cosmology · Physics 2021-01-01 Víctor H. Cárdenas , Miguel Cruz , Samuel Lepe

Extremely light bosonic wave dark matter ($\psi$DM) is an emerging dark matter candidate contesting the conventional cold dark matter paradigm and a model subject to intense scrutiny of late. This work for the first time reports testable…

Astrophysics of Galaxies · Physics 2020-09-16 James H. H. Chan , Hsi-Yu Schive , Shing-Kwong Wong , Tzihong Chiueh , Tom Broadhurst

We analyze gravitational waves propagating in an isotropic cosmic fluid endowed with a bulk viscosity $\zeta$ and a shear viscosity $\eta$, assuming these coefficients to vary with fluid density $\rho$ as $\rho^\lambda$, with $\lambda=1/2$…

General Relativity and Quantum Cosmology · Physics 2019-07-16 Iver Brevik , Shin'ichi Nojiri

It is a well-known fact that the gravitational effect of dark matter in galaxies is only noticeable when the orbital accelerations drop below $a_0 \simeq 2\times 10^{-8}$ cm s$^{-1}$ (Milgrom's Law). This peculiarity of the dynamic…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-08 L. Acedo

Gravitational potential fluctuations driven by bursty star formation can kinematically 'heat up' dark matter at the centres of dwarf galaxies. A key prediction of such models is that, at a fixed dark matter halo mass, dwarfs with a higher…

Astrophysics of Galaxies · Physics 2019-04-15 J. I. Read , M. G. Walker , P. Steger

We demonstrate a novel mechanism for producing dark compact objects and black holes through a dark sector, where all the dark matter can be dissipative. Heavy dark sector particles with masses above $10^4$ GeV can come to dominate the…

High Energy Physics - Phenomenology · Physics 2024-08-29 Joseph Bramante , Christopher V. Cappiello , Melissa D. Diamond , J. Leo Kim , Qinrui Liu , Aaron C. Vincent

In cold dark matter cosmological models, structures form and grow by merging of smaller units. Numerical simulations have shown that such merging is incomplete; the inner cores of halos survive and orbit as "subhalos" within their hosts.…

Astrophysics · Physics 2010-04-06 J. Diemand , M. Kuhlen , P. Madau , M. Zemp , B. Moore , D. Potter , J. Stadel

The large gap between a galactic dark matter subhalo's velocity and its own gravitational binding velocity creates the situation that small subhalos can be evaporated before dark matter thermalize with baryons due to the low binding…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-20 Xiao-jun Bi , Yu Gao , Mingjie Jin , Yugen Lin , Qian-Fei Xiang

We compute the properties of dark matter halos with mass $10^{6.5}-10^9\msun$ at redshift $z=6-11$ in the standard cold dark matter cosmological model, utilizing a very high resolution N-body simulation. We find that dark matter halos in…

Astrophysics · Physics 2007-05-23 Renyue Cen , Feng Dong , Paul Bode , Jeremiah P. Ostriker

The mass and composition of dark matter (DM) particles and the shape and damping scales of the power spectrum of density perturbations can be estimated from recent observations of the DM dominated relaxed objects -- dwarf galaxies and…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-22 M. Demianski , A. Doroshkevich

The Universe is modeled as consisting of pressureless baryonic matter and a bulk viscous fluid which is supposed to represent a unified description of the dark sector. In the homogeneous and isotropic background the \textit{total} energy…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-22 W. Zimdahl , H. E. S. Velten , W. S. Hipólito-Ricaldi

We examine linear perturbation theory to evaluate the contribution of viscosity coefficient in the growing of dark matter perturbations in the context of the bulk viscous dark energy model inspired by thermodynamical dissipative phenomena…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-12 B. Mostaghel , H. Moshafi , S. M. S. Movahed

We discuss a cosmology in which cold dark matter begins to decay into relativistic particles at a recent epoch (z < 1). We show that the large entropy production and associated bulk viscosity from such decays leads to an accelerating…

Astrophysics · Physics 2008-11-26 G. J. Mathews , N. Q. Lan , C. Kolda

The dark matter distribution in dwarf galaxies holds a wealth of information on the fundamental properties and interactions of the dark matter particle. In this paper, we study whether ultralight bosonic dark matter is consistent with the…

Astrophysics of Galaxies · Physics 2023-01-26 Isabelle S. Goldstein , Savvas M. Koushiappas , Matthew G. Walker