Primordial black holes from cosmic necklaces

Abstract

Cosmic necklaces are hybrid topological defects consisting of monopoles and strings. We argue that primordial black holes(PBHs) may have formed from loops of the necklaces, if there exist stable winding states, such as coils and cycloops. Unlike the standard scenario of PBH formation from string loops, in which the kinetic energy plays important role when strings collapse into black holes, the PBH formation may occur in our scenario after necklaces have dissipated their kinetic energy. Then, the significant difference appears in the production ratio. In the standard scenario, the production ratio $f$ becomes a tiny fraction $f\sim 10^{-20}$, however it becomes $f\sim 1$ in our case. On the other hand, the typical mass of the PBHs is much smaller than the standard scenario, if they are produced in the same epoch. As the two mechanisms may work at the same time, the necklaces may have more than one channel of the gravitational collapse. Although the result obtained in this paper depends on the evolution of the dimensionless parameter $r$, the existence of the winding state could be a serious problem in some cases. Since the existence of the winding state in brane models is due to the existence of a non-tivial circle in the compactified space, the PBH formation can be used to probe the structure of the compactified space. Black holes produced by this mechanism may have peculiar properties.

22pages, 3 figures, added many comments, +1 figure, accepted for publication in JHEP

References in corpus (9)

• Gravitational radiation from cosmic (super)strings: bursts, stochastic background, and observational windows
• Reheating the Universe after String Theory Inflation
• Reconnection of Non-Abelian Cosmic Strings
• Overproduction of cosmic superstrings
• Holes in the walls: primordial black holes as a solution to the cosmological domain wall problem
• Topological Curvatons
• Brane necklaces and brane coils
• Cycloops: Dark Matter or a Monopole Problem for Brane Inflation?
• Formation of monopoles and domain walls after brane inflation

Cited by in corpus (27)

• New cosmological constraints on primordial black holes
• Constraints on Primordial Black Holes
• Primordial Black Holes as Dark Matter
• Primordial Black Holes
• Primordial black holes as a dark matter candidate are severely constrained by the Galactic Center 511 keV gamma-ray line
• Constraints on Primordial Black Holes with Extended Mass Functions
• From Primordial Black Holes Abundance to Primordial Curvature Power Spectrum (and back)
• Primordial Black Holes as Dark Matter: Converting Constraints from Monochromatic to Extended Mass Distributions
• Novel Constraints on Mixed Dark-Matter Scenarios of Primordial Black Holes and WIMPs
• Lensing of fast radio bursts: future constraints on primordial black hole density with an extended mass function and a new probe of exotic compact fermion and boson stars
• Generating the curvature perturbation with instant preheating
• Elliptic Inflation: Generating the curvature perturbation without slow-roll
• Monopole annihilation in cosmic necklaces
• Brane inflation without slow-roll
• String Necklaces and Primordial Black Holes from Type IIB Strings
• Primordial Black Hole Formation in Non-Standard Post-Inflationary Epochs
• Primordial black holes from monopoles connected by strings
• Dark Stars and Gravitational Waves: Topical Review
• Remote Inflation: Hybrid-like inflation without hybrid-type potential
• Black hole formation from collisions of cosmic fundamental strings
• Spinning Primordial Black Holes from First Order Phase Transition
• Non-topological Cycloops
• A Generalisation of the Nielsen-Olesen Vortex: Non-cylindrical strings in a modified Abelian-Higgs model
• Gravitational Wave Signatures of Primordial Black Hole Reheating in Upcoming Interferometry Missions
• Can Superconducting Cosmic Strings Piercing Seed Black Holes Generate Supermassive Black Holes in the Early Universe?
• Signatures of Compact Halos of Sterile-Neutrino Dark Matter
• Casimir force for cosmological domain walls