scholarly journals Limits on primordial black holes from μ distortions in cosmic microwave background

2018 ◽  
Vol 97 (4) ◽  
Author(s):  
Tomohiro Nakama ◽  
Bernard Carr ◽  
Joseph Silk
Keyword(s):  
Black Holes ◽  
Cosmic Microwave Background ◽  
Primordial Black Holes ◽  
Microwave Background

scholarly journals Searching for dark matter constituents with many solar masses

2016 ◽  
Vol 31 (16) ◽  
pp. 1650093 ◽  
Author(s):  
Paul H. Frampton
Keyword(s):  
Black Holes ◽  
Dark Matter ◽  
Cosmic Microwave Background ◽  
Massive Particle ◽  
Search Strategies ◽  
Observational Constraints ◽  
Primordial Black Holes ◽  
Microwave Background ◽  
Weak Scale ◽  
Weakly Interacting

Searches for dark matter (DM) constituents are presently mainly focused on axions and weakly interacting massive particle (WIMPs) despite the fact that far higher mass constituents are viable. We discuss and dispute whether axions exist and those arguments for WIMPs which arise from weak scale supersymmetry. We focus on the highest possible masses and argue that, since if they constitute all DM, they cannot be baryonic, they must uniquely be primordial black holes. Observational constraints require them to be of intermediate masses mostly between ten and a hundred thousand solar masses. Known search strategies for such PIMBHs include wide binaries, cosmic microwave background (CMB) distortion and, most promisingly, extended microlensing experiments.

scholarly journals Maximum PBH mass and primordiality

2018 ◽  
Vol 33 (31) ◽  
pp. 1850176
Author(s):  
Paul H. Frampton
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Cosmic Microwave Background ◽  
Observational Data ◽  
Supermassive Black Holes ◽  
Primordial Black Holes ◽  
Black Hole Mass ◽  
Microwave Background

In order to avoid unacceptable [Formula: see text]-distortions inconsistent with observational data on the Cosmic Microwave Background, Primordial Black Holes (PBHs) must be less massive than [Formula: see text], quite closely above the highest black hole mass yet observed. This comparableness leads us to posit that all supermassive black holes originate as PBHs.

scholarly journals Are Cosmic Isotropy Limits from Analyses of the Cosmic Microwave Background Credible?

2020 ◽  
Author(s):  
Michael J. Longo
Keyword(s):  
Angular Momentum ◽  
Cosmic Microwave Background ◽  
Parity Violation ◽  
Large Scale ◽  
Magnetic Moments ◽  
Primordial Black Holes ◽  
Spin Angular Momentum ◽  
Microwave Background ◽  
Fundamental Symmetry ◽  
The Universe

Recent analyses of cosmic microwave background (CMB) maps have been interpreted as demonstrating that the Universe was born without an initial rotation. However, these analyses are based on unrealistic models and do not contain essential ingredients such as quantum effects, the strong, weak and gravitational interactions between the components, their intrinsic spins and magnetic moments, as well as primordial black holes. If the Universe was born spinning these effects would distribute the initial spin angular momentum among its components long before the CMB forms at recombination. A primordial spin would now appear as a nonzero total angular momentum of its components along the direction of the original spin, and a primordial large-scale rotation would no longer be apparent. The existence of a special axis or direction would break a fundamental symmetry assumed in general relativity, cosmic isotropy, and a net angular momentum implies a cosmic parity violation.

scholarly journals GW200105 and GW200115 are compatible with a scenario of primordial black hole binary coalescences

2022 ◽  
Vol 82 (1) ◽  
Author(s):  
Sai Wang ◽  
Zhi-Chao Zhao
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Cold Dark Matter ◽  
Primordial Black Hole ◽  
Primordial Black Holes ◽  
Microwave Background ◽  
Black Hole Binaries ◽  
Upper Limits ◽  
Merger Rate ◽  
The One

AbstractTwo gravitational wave events, i.e. GW200105 and GW200115, were observed by the Advanced LIGO and Virgo detectors recently. In this work, we show that they can be explained by a scenario of primordial black hole binaries that are formed in the early Universe. The merger rate predicted by such a scenario could be consistent with the one estimated from LIGO and Virgo, even if primordial black holes constitute a fraction of cold dark matter. The required abundance of primordial black holes is compatible with the existing upper limits from microlensing, caustic crossing and cosmic microwave background observations.

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