Results 81 to 90 of about 38,917 (207)
Primordial black holes as supermassive black hole seeds
Journal of Cosmology and Astroparticle PhysicsAbstract The presence of supermassive black holes (SMBHs, M • ∼ 106-10 M ⊙) in the first cosmic Gyr (z ≳ 6) challenges current models of BH formation and evolution. We propose a novel mechanism for the formation of early SMBH seeds based on primordial black holes (PBHs).
F. Ziparo, S. Gallerani, A. Ferrara
openaire +2 more sources
Spin Distribution of Primordial Black Holes
, 2017 We estimate the spin distribution of primordial black holes based on the recent study of the critical phenomena in the gravitational collapse of a rotating radiation fluid. We find that primordial black holes are mostly slowly rotating.Comment: 12 pages,
Chiba, Takeshi, Yokoyama, Shuichiro
core +1 more source
Non-Primordial Solar Mass Black Holes [PDF]
, 2018 We propose a mechanism that can convert a sizeable fraction of neutron stars into black holes with mass $\sim 1M_\odot$, too light to be produced via standard stellar evolution.
Kouvaris, Chris +2 more
core +2 more sources
Enhancement of Coherence Times of Individual Shallow NV Center due to Ozone Treatment
Advanced Quantum Technologies, Volume 9, Issue 4, April 2026.It has been observed a threefold improvement in T2∗$T_2^*$ by probing the spin properties of the same individual shallow NVs (depth < 20 nm) before and after ozone treatment, and one order of magnitude enhancement in T2${T_2}$, for NVs coated with a layer of isotopically purified 12C${\;^{12}}C$ (depth < 40 nm).
Jéssica Fernanda da Silva Barbosa +8 more
wiley +1 more source
Evolution of a primordial black hole population
Physical Review D, 1998 We reconsider in this work the effects of an energy absorption term in the evolution of primordial black holes (hereafter PBHs) in the several epochs of the Universe. A critical mass is introduced as a boundary between the accreting and evaporating regimes of the PBHs.
Custodio, P. S., Horvath, J. E.
openaire +2 more sources
The Open Journal of AstrophysicsThe formation of supermassive black holes (SMBHs) in the early Universe is a subject of significant debate. In this study, we examine whether non-evaporating primordial black holes (PBHs) can offer a solution.
Jonathan Regan +2 more
doaj +1 more source
Origin of Correlations between Central Black Holes Masses and Galactic Bulge Velocity Dispersions [PDF]
, 2002 We argue that the observed correlations between central black holes masses M_{BH} and galactic bulge velocity dispersions \sigma_e in the form M_{BH}\propto\sigma_e^4 may witness on the pregalactic origin of massive black holes.
Starobinsky A. A. +3 more
core +3 more sources
“It Will Get Crowded, It Will Get Dull!”: Preventive Sensations of Density in Zurich's Future‐Making
City &Society, Volume 38, Issue 1, April 2026.ABSTRACT In Zurich, Switzerland's largest and wealthiest city, future planning around densification has been intensely debated in recent years, spurring referendums and direct democratic votes, and permeating the public discourse through governmental communication, political propaganda, and heightened media coverage.
Sabrina Stallone
wiley +1 more source
PRIMORDIAL BLACK HOLES AND EARLY COSMOLOGY [PDF]
COSMO-97, 1998 We describe the changes to the standard primordial black hole constraints on density perturbations if there are modifications to the standard cosmology between the time of formation and nucleosynthesis.
Liddle, Andrew R, Green, Anne M
openaire +2 more sources
Physical Review ResearchMultiple pulsar-timing-array collaborations have reported strong evidence for the existence of a gravitational-wave background. We study physical implications of this signal for cosmology, assuming that it is attributed to scalar-induced gravitational ...
Sai Wang +3 more
doaj +1 more source