Primordial black holes from cosmic domain walls

Abstract

We investigate the formation of primordial black holes (PBHs) from the collapse of spherically symmetric domain wall bubbles, which spontaneously nucleate via quantum tunneling during inflation. Since the tension of domain walls changes with time and so domain walls nucleate in a short time interval, the mass function of PBHs in general has a spike-like structure. In contrast to models in which PBHs produced from overdense regions, our model avoids the uncertainties of PBHs production mechanism. PBHs from domain walls with mass around 10 20 g may constitute all dark matter, those with mass around 10 34 g can explain the merger events of binary black holes detected by LIGO.

Multi-Field versus Single-Field in the Supergravity Models of Inflation and Primordial Black Holes

“…There are several mechanisms that may catalyze the formation of PBH in the early Universe: (i) gravitational instabilities induced by scalar fields [27] in single-field or multi-field inflation, (ii) bubble collisions from first order phase transitions [28][29][30], and (iii) formation of critical topological defects such as cosmic strings [31] and domain walls [32,33]. This paper is devoted to the case (i) only.…”

Primordial black holes from modified supergravity

“…There are several mechanisms that may catalyze the formation of PBHs: (i) gravitational instabilities induced from scalar fields [3] such as axion-like particles or multifield inflation, (ii) bubble-bubble collisions from first order phase transitions (see Refs. [4][5][6] for recent discussions), and (iii) formation of critical topological defects such as cosmic strings [7] and domain walls [8,9] in the early Universe.…”

Scalar induced gravitational waves in inflation with gravitationally enhanced friction

“…The mechanisms of amplifying the small-scale curvature perturbations within the infla- 1 It is worthing pointing out that the scalar induced GWs are gauge independent [26][27][28]. tionary scenario have been extensively studied in recent years [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45]. The most common mechanism is the single-field inflection-point inflation [38][39][40][41][42][43][44][45], which requires that the potential of the inflaton field has an approximate inflection point.…”