Self-consistent spherical accretion simulations show cooling-enhanced growth of PBHs with radiative efficiency ~10^{-2} in the bremsstrahlung regime, yielding a critical seed mass of ~10^{-16} M_sun to consume a solar-mass star in a Hubble time.
hub Mixed citations
New cosmological constraints on primordial black holes
Mixed citation behavior. Most common role is background (67%).
abstract
We update the constraints on the fraction of the Universe going into primordial black holes in the mass range 10^9--10^17 g associated with the effects of their evaporations on big bang nucleosynthesis and the extragalactic photon background. We include for the first time all the effects of quark and gluon emission by black holes on these constraints and account for the latest observational developments. We then discuss the other constraints in this mass range and show that these are weaker than the nucleosynthesis and photon background limits, apart from a small range 10^13--10^14 g, where the damping of cosmic microwave background anisotropies dominates. Finally we review the gravitational and astrophysical effects of nonevaporating primordial black holes, updating constraints over the broader mass range 1--10^50 g.
hub tools
citation-role summary
citation-polarity summary
representative citing papers
Non-singular gravity with regulator ℓ induces a PBH mass gap ~c²ℓ/G and a stronger Carr criterion δ_H > 2GM_gap/R_H - 1 when R_H ~ ℓ.
Accounting for the minimal mass spread of primordial black holes from gravitational collapse suppresses the Poltergeist GW background to the level of generic scalar-induced signals and reopens ultra-light PBH parameter space.
Stupendously large black holes cast shadows on the CMB that rule out masses above 10^17 solar masses within the last scattering surface and limit their density parameter to below 10^-5 for masses 10^15 to 10^18 solar masses.
In the ADD extra-dimension model, microscopic primordial black holes undergo runaway accretion and grow to macroscopic scales, allowing them to comprise all dark matter with initial abundances as low as 10^{-44}.
Incorporating the general-relativity mass tail df_PBH/d ln M ∝ M^3.78 smooths PBH evaporation, suppresses the scalar-induced GW signal by orders of magnitude, and reopens the ultra-light PBH window for the hot Big Bang.
Tensor perturbations from first-order phase transitions and domain wall annihilation induce curvature fluctuations at second order that form primordial black holes, allowing asteroid-mass PBHs to comprise all dark matter for specific parameter ranges with associated gravitational wave peaks in LISA,
Primordial black holes generate up to 30% amplitude VAO wiggles in 21 cm signals from the Dark Ages at redshifts 20-40 even at dark matter fractions as low as 10^-13.
Hotspots around light primordial black holes cool faster in an expanding universe following T_plt ∝ t^{-11/15} and vanish completely in finite time, unlike everlasting hotspots in flat spacetime.
PBH masses near 10^3 kg allow Hawking evaporation to reheat the universe while Planckian remnants comprise all present-day DM without fine-tuning initial abundance, yielding testable GW signals.
Calculations indicate AMEGO-X could detect PBH transits within 0.1 AU while HAWC and LHAASO could observe explosions out to 0.1-0.5 pc, with future events at ~1000 AU potentially producing measurable electromagnetic signals unlike the 2023 KM3NeT neutrino candidate.
In excursion set theory with colored noises, the low-mass tail of the PBH mass function differs from Carr's formula because correlated noises end the degeneracy of formation probabilities, though Carr's formula remains practical near the characteristic mass for smooth Fourier-space window functions.
Combining regular black hole metrics with memory burden suppresses evaporation and opens a 10^6-10^8 g PBH mass window that can comprise all dark matter.
Inflationary magnetic fields induce curvature perturbations that form ultralight PBHs, generating a stochastic GW background with model-specific features.
Deformed alpha-attractor T-models with a Gaussian feature near the minimum yield more smaller shorter-lived oscillons during self-resonance preheating, suppressing energy in oscillons and altering the high-frequency gravitational wave tail while leaving low frequencies unchanged.
Galactic synchrotron emissions above 20 MHz can set tighter upper limits on the abundance of primordial black holes with masses above 10^16 grams than previous cosmic-ray electron data.
Thermal bath corrections derived via thermofield dynamics enhance the evaporation rate of primordial black holes, shortening their lifetimes relative to zero-temperature calculations.
Regular primordial black holes can evaporate completely like singular ones and yield the observed dark matter density under modified cosmological constraints.
For ultra-light PBHs with extended mass distributions, new CMB-derived 95% exclusion bounds on f_PBH are obtained by jointly varying ΛCDM parameters, yielding f_PBH < 1.6 × 10^{-5} for a uniform distribution between 10^{15} and 10^{17} g.
Purely quadratic non-Gaussianity from tachyonic instability allows narrow curvature spectra to exponentially suppress primordial black hole overproduction via correlation coefficient ρ approaching -1 while retaining sizable scalar-induced gravitational waves.
Memory-burden backreaction deforms the Hawking spectrum to suppress its high-energy tail, lowering total luminosity and neutrino flux by a factor set by a single suppression parameter and thereby relaxing IceCube bounds on primordial black hole dark matter.
Explores SKAO detection of scalar-induced GW backgrounds as probes of primordial non-Gaussianity and parity violation, with LSS cross-correlation to improve SNR.
PBH-triggered SN Ia models across metallicities match some observed light curves and remnants, constrain the explosion channel fraction via chemical evolution modeling, and indicate PBHs as a potentially major early-universe SN Ia source.
Accretion on primordial black holes prolongs matter domination and shifts reheating constraints from isocurvature gravitational waves and mergers toward smaller formation masses and initial abundances.
citing papers explorer
-
Evaporation of Primordial Black Holes in a Thermal Universe: A Thermofield Dynamics Approach
Thermal bath corrections derived via thermofield dynamics enhance the evaporation rate of primordial black holes, shortening their lifetimes relative to zero-temperature calculations.