scholarly journals Reshaping our understanding on structure formation with the quantum nature of the dark matter

2021 ◽  
Author(s):  
C. R. Argüelles ◽  
E. A. Becerra-Vergara ◽  
A. Krut ◽  
R. Yunis ◽  
J. A. Rueda ◽  
...  
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Structure Formation ◽  
Initial Conditions ◽  
Coarse Grained ◽  
Intermediate Mass ◽  
Open Problems ◽  
Nonlinear Structure ◽  
The Core ◽  
Quantum Nature

We study the nonlinear structure formation in cosmology accounting for the quantum nature of the dark matter (DM) particles in the initial conditions at decoupling, as well as in the relaxation and stability of the DM halos. Different from cosmological N-body simulations, we use a thermodynamic approach for collisionless systems of self-gravitating fermions in general relativity, in which the halos reach the steady state by maximizing a coarse-grained entropy. We show the ability of this approach to provide answers to crucial open problems in cosmology, among others: the mass and nature of the DM particle, the formation and nature of supermassive black holes in the early Universe, the nature of the intermediate mass black holes in small halos, and the core-cusp problem.

scholarly journals On the formation and stability of fermionic dark matter halos in a cosmological framework

2020 ◽  
Author(s):  
Carlos R Argüelles ◽  
Manuel I Díaz ◽  
Andreas Krut ◽  
Rafael Yunis
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Space Distribution ◽  
Coarse Grained ◽  
Dark Matter Halos ◽  
The Core ◽  
The Galaxy ◽  
Gravitating Systems ◽  
The Given ◽  
First Time

Abstract The formation and stability of collisionless self-gravitating systems is a long standing problem, which dates back to the work of D. Lynden-Bell on violent relaxation, and extends to the issue of virialization of dark matter (DM) halos. An important prediction of such a relaxation process is that spherical equilibrium states can be described by a Fermi-Dirac phase-space distribution, when the extremization of a coarse-grained entropy is reached. In the case of DM fermions, the most general solution develops a degenerate compact core surrounded by a diluted halo. As shown recently, the latter is able to explain the galaxy rotation curves while the DM core can mimic the central black hole. A yet open problem is whether this kind of astrophysical core-halo configurations can form at all, and if they remain stable within cosmological timescales. We assess these issues by performing a thermodynamic stability analysis in the microcanonical ensemble for solutions with given particle number at halo virialization in a cosmological framework. For the first time we demonstrate that the above core-halo DM profiles are stable (i.e. maxima of entropy) and extremely long lived. We find the existence of a critical point at the onset of instability of the core-halo solutions, where the fermion-core collapses towards a supermassive black hole. For particle masses in the keV range, the core-collapse can only occur for Mvir ≳ E9M⊙ starting at zvir ≈ 10 in the given cosmological framework. Our results prove that DM halos with a core-halo morphology are a very plausible outcome within nonlinear stages of structure formation.

scholarly journals Dark matter gravity waves at LIGO and LISA

2019 ◽  
Vol 34 (16) ◽  
pp. 1950124
Author(s):  
Paul H. Frampton
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Gravitational Wave ◽  
Gravity Waves ◽  
Gravitational Radiation ◽  
Massive Stars ◽  
Strain Sensitivity ◽  
Intermediate Mass ◽  
To Come ◽  
Merger Rate

We study the merger rate of dark matter PIMBHs (Primordial Intermediate Mass Black Holes). We conclude that the black holes observed by LIGO in GW150914 and later events were probably not dark matter PIMBHs but rather the result of gravitational collapse of very massive stars. To study the PIMBHs by gravitational radiation will require a detector sensitive to frequencies below 10 Hz and otherwise more sensitive than LIGO. The LISA detector, expected to come online in 2034, will be useful at frequencies below 1 Hz but further gravitational wave detectors beyond LISA, sensitive up to 10 Hz, and higher strain sensitivity will be necessary to fully study dark matter.

scholarly journals Dark matter annihilation around intermediate mass black holes: an update

2009 ◽  
Vol 11 (10) ◽  
pp. 105016 ◽  
Author(s):  
Gianfranco Bertone ◽  
Mattia Fornasa ◽  
Marco Taoso ◽  
Andrew R Zentner
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Intermediate Mass ◽  
Dark Matter Annihilation ◽  
Intermediate Mass Black Holes

A 3D hydrodynamic simulation of a black hole outflow in a dwarf spheroidal galaxy

2018 ◽  
Vol 14 (S344) ◽  
pp. 296-300
Author(s):  
Gustavo A. Lanfranchi ◽  
Anderson Caproni ◽  
Roberto Hazenfratz
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Initial Velocity ◽  
Initial Conditions ◽  
Three Dimensional ◽  
Homogeneous Medium ◽  
Intermediate Mass ◽  
Hydrodynamic Simulation ◽  
Dwarf Spheroidal Galaxies ◽  
The Galaxy

AbstractWe present results from a non-cosmological, three-dimensional hydrodynamic simulation of an outflow from an intermediate-mass black hole in Dwarf Spheroidal Galaxies. Assuming an initial baryonic-to-dark-matter ratio derived from the CMB radiation and a cored, static dark matter potential, we evolved the galactic gas distribution over 3 Gyr, taking into account the outflow of a black hole. Our results indicate that in a homogeneous medium the outflow propagates freely in both directions with the same velocity and its capable of removing a fraction of the gas from the galaxy (it depends on the initial conditions of the outflow). When the SNe are taken into account, the effect of the outflow is substantially reduced. It is necessary an initial velocity around 1000 km/s and a density larger than 0.003 particles.cm−3 for the outflow to propagate. In these conditions, the removal of gas from the galaxy is almost negligible at the end of the 3 Gyr of the simulation.

scholarly journals Primordial intermediate mass black holes as dark matter

2020 ◽  
Vol 35 (36) ◽  
pp. 2044028
Author(s):  
Paul H. Frampton
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Magellanic Clouds ◽  
Experimental Confirmation ◽  
Particle Theory ◽  
Intermediate Mass ◽  
Intermediate Mass Black Holes

Among particle theory candidates for the dark matter constituents. Axions and WIMPs are the most popular. In this paper, we discuss these then focus on our preferred astrophysical candidate, the Primordial Intermediate Mass Black Holes in the acronym DM[Formula: see text]=[Formula: see text]PIMBHs. The earliest experimental confirmation may come from microlensing of the Magellanic Clouds at the LSST 8 m telescope in the mid-2020s, or possibly a few years earlier in 2021 from work being pursued, using DECam data from the smaller Blanco 4 m telescope, at LLNL.

scholarly journals Origins of Stellar Mass Neutron Black Holes, Supermassive Dark Matter Black Holes and Universe Evolution

2021 ◽  
Author(s):  
Jae-Kwang Hwang
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Dark Matter ◽  
Big Bang ◽  
Stellar Mass ◽  
Intermediate Mass ◽  
Milky Way Galaxy ◽  
Dark Matters ◽  
The Big Bang ◽  
Universe Evolution

The origins of the stellar mass neutron black holes and supermassive dark matter black holes without the singularities are reported based on the 4-D Euclidean space. The neutron black holes with the mass of mBH = 5 – 15 msun are made by the 6-quark merged states (N6q) of two neutrons with the mass (m(N6q) = 10 m(n)) of 9.4 GeV/c2 that gives the black hole mass gap of mBH = 3 – 5 msun. Also, the supermassive black holes with the mass of mSMBH = 106 – 1011 msun are made by the merged 3-D states (J(B1B2B3)3 particles) of the dark matters. The supermassive black hole at the center of the Milky way galaxy has the mass of mSMBH = 4.1 106 msun that is consistent with mSMBH = 2.08 - 6.23 106 msun calculated from the 3-D states (J(B1B2B3)3 particles) of the dark matters with the mass of m(J) = 1.95 1015 eV/c2. In other words, this supports the existence of the B1, B2 and B3 dark matters with the proposed masses. The first dark matter black hole (primary black hole) was created at the big bang. This first dark matter black hole decayed to the supermassive dark matter black holes through the secondary dark matter black holes that are explained by the merged states of the J(B1B2B3)3 particles. The universe evolution is closely connected to the decaying process of the dark matter black holes since the big bang. The dark matter cloud states are proposed at the intermediate mass black hole range of mIMBH = 102 – 105 msun. This can explain why the dark matter black holes are not observed at the intermediate mass black hole range of mIMBH = 102 – 105 msun.

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