LIGO/Virgo BH spins limit dark matter
- notFritzArgelander
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LIGO/Virgo BH spins limit dark matter
Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
- AntennaGuy
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Re: LIGO/Virgo BH spins limit dark matter
Interesting. But it looks like it only excludes a very narrow range of possible masses. "The black holes' existence rules out the existence of ultralight bosons with masses between 1.3x10^-13 electronvolts and 2.7x10^-13 electronvolts."
* Meade 323 refractor on a manual equatorial mount.
* Celestron C6 SCT on a Twilight 1 Alt-Az mount
Prof. Barnhardt to Klaatu in The Day the Earth Stood Still: "There are several thousand questions I'd like to ask you.”
* Celestron C6 SCT on a Twilight 1 Alt-Az mount
Prof. Barnhardt to Klaatu in The Day the Earth Stood Still: "There are several thousand questions I'd like to ask you.”
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Re: LIGO/Virgo BH spins limit dark matter
Quite true and the paper abstract is much more modest than the article:AntennaGuy wrote: ↑Wed Apr 14, 2021 9:03 pm Interesting. But it looks like it only excludes a very narrow range of possible masses. "The black holes' existence rules out the existence of ultralight bosons with masses between 1.3x10^-13 electronvolts and 2.7x10^-13 electronvolts."
https://arxiv.org/abs/1908.02312
The bold emphasis is mine.Ultralight bosons can form clouds around rotating black holes if their Compton wavelength is comparable to the black hole size. The boson cloud spins down the black hole through a process called superradiance, lowering the black hole spin to a characteristic value. It has been suggested that spin measurements of the black holes detected by ground-based gravitational-wave detectors can be used to constrain the mass of ultralight bosons. Unfortunately, a measurement of the individual black hole spins is often uncertain, resulting in inconclusive results. Instead, we use hierarchical Bayesian inference to combine information from multiple gravitational-wave sources and obtain stronger constraints. We show that hundreds of high signal-to-noise ratio gravitational-wave detections are enough to exclude (confirm) the existence of non-interacting bosons in the mass range [10−13,3×10−12] eV ([10−13,10−12] eV). The precise number depends on the distribution of black hole spins at formation and the mass of the boson. From the few uninformative spin measurements of binary black hole mergers detected by LIGO and Virgo in their first two observing runs, we cannot draw statistically significant conclusions.
The problem with this method is that the Compton wavelength needs to be of the order of the event horizon. Since the masses of merging BHs are in a small range only a small range can be excluded. As an antenna person, you know how that works, the relationship between simple antennas and wavelength....
Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
- AntennaGuy
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Re: LIGO/Virgo BH spins limit dark matter
Re: "PS How's the VMC working out?"
Believe it or not, I still haven't actually set it up to use it yet! Hoping to get some time & opportunity sooner rather than later.
Believe it or not, I still haven't actually set it up to use it yet! Hoping to get some time & opportunity sooner rather than later.
* Meade 323 refractor on a manual equatorial mount.
* Celestron C6 SCT on a Twilight 1 Alt-Az mount
Prof. Barnhardt to Klaatu in The Day the Earth Stood Still: "There are several thousand questions I'd like to ask you.”
* Celestron C6 SCT on a Twilight 1 Alt-Az mount
Prof. Barnhardt to Klaatu in The Day the Earth Stood Still: "There are several thousand questions I'd like to ask you.”
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