The formation of primary galactic nuclei during phase transitions in the early universe

We discuss a new class of solutions to the Einstein equations which describe a primordial black hole (PBH) in a flat Friedmann background. Such solutions arise if a Schwarzschild black hole is patched onto a Friedmann background via a transition region. They are possible providing the black hole event horizon is larger than the cosmological apparent horizon. Such solutions have a number of strange features. In particular, one has to define the black hole and cosmological horizons carefully and one then finds that the mass contained within the black hole event horizon decreases when it is larger than the Friedmann cosmological apparent horizon, although its area always increases. These solutions involve two distinct future null infinities and are interpreted as the conversion of a white hole into a black hole. Although such solutions may not form from gravitational collapse in the same way as standard PBHs, there is nothing unphysical about them, since all energy and causality conditions are satisfied. Their conformal diagram is a natural amalgamation of the Kruskal diagram for the extended Schwarzschild solution and the conformal diagram for a black hole in a flat Friedmann background. In this paper, such solutions are obtained numerically for a spherically symmetric universe containing a massless scalar field, but it is likely that they exist for more general matter fields and less symmetric systems.

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“…[13]. In this scenario, super-horizon PBHs may naturally arise due to the closed domain walls of size exceeding the cosmological horizon.…”

Section: Resultsmentioning

confidence: 99%

Super-horizon primordial black holes

Harada

Carr

2005

Phys. Rev. D

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“…Their existence as fully formed galaxies before 500 Myr is a challenge for the standard ΛCDM model. It is extremely difficult to form such a massive BH so quickly from stellar evolution, and several proposals suggest that they are built up from smaller BHs that act as seeds of the galactic SMBHs [93][94][95][96][97][98].…”

Section: The Seed Of Supermassive Black Holesmentioning

confidence: 99%

Massive primordial black holes from hybrid inflation as dark matter and the seeds of galaxies

2015

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In this paper we present a new scenario where massive primordial black holes (PBHs) are produced from the collapse of large curvature perturbations generated during a mild-waterfall phase of hybrid inflation. We determine the values of the inflaton potential parameters leading to a PBH mass spectrum peaking on planetarylike masses at matter-radiation equality and producing abundances comparable to those of dark matter today, while the matter power spectrum on scales probed by cosmic microwave background (CMB) anisotropies agrees with Planck data. These PBHs could have acquired large stellar masses today, via merging, and the model passes both the constraints from CMB distortions and microlensing. This scenario is supported by Chandra observations of numerous BH candidates in the central region of Andromeda. Moreover, the tail of the PBH mass distribution could be responsible for the seeds of supermassive black holes at the center of galaxies, as well as for ultraluminous x-ray sources. We find that our effective hybrid potential can originate e.g. from D-term inflation with a Fayet-Iliopoulos term of the order of the Planck scale but sub-Planckian values of the inflaton field. Finally, we discuss the implications of quantum diffusion at the instability point of the potential, able to generate a Swiss-cheese-like structure of the Universe, eventually leading to apparent accelerated cosmic expansion.

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“…This mechanism can lead to the formation of primordial black holes of a whatever large mass (up to the mass of active galactic nuclei (AGNs) [123,124], see for latest review Reference [35]). Such black holes appear in the form of primordial black hole clusters, exhibiting fractal distribution in space [114,122,125].…”

Section: Primordial Seeds For Active Galactic Nucleimentioning

confidence: 99%

Cosmological Reflection of Particle Symmetry

Khlopov

2016

Symmetry

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The standard model involves particle symmetry and the mechanism of its breaking. Modern cosmology is based on inflationary models with baryosynthesis and dark matter/energy, which involves physics beyond the standard model. Studies of the physical basis of modern cosmology combine direct searches for new physics at accelerators with its indirect non-accelerator probes, in which cosmological consequences of particle models play an important role. The cosmological reflection of particle symmetry and the mechanisms of its breaking are the subject of the present review.

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The formation of primary galactic nuclei during phase transitions in the early universe

Abstract: Below we will consider a new mechanism describing the early formation of PBHs, which serve as the nucleation centers in the subsequent formation of galaxies. This mechanism may prove to be free from dis-

Cited by 195 publications

References 11 publications

Super-horizon primordial black holes

Super-horizon primordial black holes

Massive primordial black holes from hybrid inflation as dark matter and the seeds of galaxies

Cosmological Reflection of Particle Symmetry

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