<p>D. Baumann et al., published the article hypothesizing existence of &quot;gravitational atom” black holes (not sure whether those are just stellar ones or also those could be supermassive black holes as well?), which have a cloud of hypothetical ultralight bosons formed around it.
They suggested that existence of  &quot;gravitational atom” black holes could be detected by registering specific quirks in the caption of gravitational waves caused by collision of such &quot;gravitational atom” black hole with another stellar black hole (though the capture of such quirks is not possible now using LIGO, Virgo and KAGRA detectors but will be possible using LISA, the space-based gravitational-wave detector,
which will be available in 2037).
<a href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.128.221102" rel="nofollow noreferrer">https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.128.221102</a></p>
<p>Meanwhile Jessica Lu and Casey Lam from Berkeley announced that they found free floating stellar black hole by detecting (using Hubble) its gravitational microlensing effect.
Lam, Casey &amp; Lu, Jessica &amp; Udalski, Andrzej &amp; Bond, Ian &amp; Bennett, David &amp; Skowron, Jan &amp; Mroz, Przemek &amp; Poleski, Radek &amp; Sumi, Takahiro &amp; Szymanski, Michal &amp; Kozlowski, Szymon &amp; Pietrukowicz, Pawel &amp; Soszynski, Igor &amp; Ulaczyk, Krzysztof &amp; Wyrzykowski, Łukasz &amp; Miyazaki, Shota &amp; Suzuki, Daisuke &amp; Koshimoto, Naoki &amp; Rattenbury, Nicholas &amp; Terry, Sean. (2022). An isolated mass gap black hole or neutron star detected with astrometric microlensing.</p>
<p>Is there any possible difference in the effect of the gravitational microlensing caused by a “gravitational atom” black hole vs gravitational lensing caused by a &quot;regular&quot; black hole, that doesn't have a cloud of hypothetical ultralight bosons formed around it and could such difference be detected?</p>

CC BY-SA 4.0
2022-06-22T00:48:20.597Z
@TimRias - edited. If you agree with my edit, then you could delete (if you wish to do so) your comment...
Alex
CC BY-SA 4.0
2022-06-22T09:46:48.560Z
Sahu et al actually reported this first, and they constrain the mass to be greater than the maximum mass of a neutron star... https://arxiv.org/abs/2201.13296
Daddy Kropotkin
CC BY-SA 4.0
2022-06-29T17:53:47.630Z
@Daddy Kropotkin I presume that both teams used Bayesian inference and Markov Chain Monte Carlo sampling methods?
Alex
CC BY-SA 4.0
2022-07-01T16:34:55.767Z
For what? This isn't a gravitational wave observation. It's from photometric and astrometric data.
Daddy Kropotkin
CC BY-SA 4.0
2022-07-01T18:19:53.693Z
@Daddy Kropotkin Bartolic_-_ScotDIST_conference_talk.pdf 
 
 https://www.researchgate.net/publication/227651814_Fast_and_reliable_Markov_chain_Monte_Carlo_technique_for_cosmological_parameter_estimation
Alex
CC BY-SA 4.0
2022-07-02T12:31:26.760Z
How is that relevant for the papers that you cite in your post above...?
Daddy Kropotkin
CC BY-SA 4.0
2022-07-02T15:12:15.897Z
@Daddy Kropotkin - I think it is relevant to my comment addressed to you where I asked whether Bayesian Inference and Markov Chain  Monte Carlo sample method were (or could be) applied in analysis of the data obtained by Sahu at al and by Jessica Lu at al ... You claim that Bayesian Inference and Markov Chain  Monte Carlo sample method are not applicable for microlensing research... I think that I found counterexamples and I presented those for your kind attention...
Alex
CC BY-SA 4.0
2022-07-04T11:25:20.683Z
The paper you referenced in your previous comment is about cosmological parameter estimation. I don't see how it's about microlensing of black holes. The Sahu and Lu papers were not using Bayesian parameter estimation. Read the Sahu paper, they explain the theory of their computations pretty well.
Daddy Kropotkin
CC BY-SA 4.0
2022-07-04T11:36:57.970Z
@Daddy Kropotkin Did you look in the same comment of mine at the pdf file featuring research titled "Bayesian modelling of gravitational microlensing events"?
Alex
CC BY-SA 4.0
2022-07-05T13:22:29.987Z
No I don't see that comment, I see your comment that links to this article: Fast and reliable Markov chain Monte Carlo technique for cosmological parameter estimation https://www.researchgate.net/publication/227651814_Fast_and_reliable_Markov_chain_Monte_Carlo_technique_for_cosmological_parameter_estimation
Daddy Kropotkin
CC BY-SA 4.0
2022-07-06T00:12:06.710Z
@Daddy Kropotkin Bartolic_-_ScotDIST_conference_talk.pdf
Alex
<observational-astronomy><black-hole><gravitational-lensing><lisa>
Could "gravitational atom” black hole be detected using observation of gravitational microlensing?
Alex
# Could "gravitational atom” black hole be detected using observation of gravitational microlensing?

(Asked by: username_0 on 2022-06-21)

D. Baumann et al., published the article hypothesizing existence of "gravitational atom” black holes (not sure whether those are just stellar ones or also those could be supermassive black holes as well?), which have a cloud of hypothetical ultralight bosons formed around it.
They suggested that existence of "gravitational atom” black holes could be detected by registering specific quirks in the caption of gravitational waves caused by collision of such "gravitational atom” black hole with another stellar black hole (though the capture of such quirks is not possible now using LIGO, Virgo and KAGRA detectors but will be possible using LISA, the space-based gravitational-wave detector,
which will be available in 2037).
<https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.128.221102>

Meanwhile Jessica Lu and Casey Lam from Berkeley announced that they found free floating stellar black hole by detecting (using Hubble) its gravitational microlensing effect.
Lam, Casey & Lu, Jessica & Udalski, Andrzej & Bond, Ian & Bennett, David & Skowron, Jan & Mroz, Przemek & Poleski, Radek & Sumi, Takahiro & Szymanski, Michal & Kozlowski, Szymon & Pietrukowicz, Pawel & Soszynski, Igor & Ulaczyk, Krzysztof & Wyrzykowski, Łukasz & Miyazaki, Shota & Suzuki, Daisuke & Koshimoto, Naoki & Rattenbury, Nicholas & Terry, Sean. (2022). An isolated mass gap black hole or neutron star detected with astrometric microlensing.

Is there any possible difference in the effect of the gravitational microlensing caused by a “gravitational atom” black hole vs gravitational lensing caused by a "regular" black hole, that doesn't have a cloud of hypothetical ultralight bosons formed around it and could such difference be detected?

**Tags:** observational-astronomy, black-hole, gravitational-lensing, lisa

> **Comments:**
> **username_0**: @TimRias - edited. If you agree with my edit, then you could delete (if you wish to do so) your comment...  
> **username_1**: Sahu et al actually reported this first, and they constrain the mass to be greater than the maximum mass of a neutron star... https://arxiv.org/abs/2201.13296  
> **username_0**: @username_1 I presume that both teams used Bayesian inference and Markov Chain Monte Carlo sampling methods?  
> **username_1**: For what? This isn't a gravitational wave observation. It's from photometric and astrometric data.  
> **username_0**: @username_1 Bartolic_-_ScotDIST_conference_talk.pdf     https://www.researchgate.net/publication/227651814_Fast_and_reliable_Markov_chain_Monte_Carlo_technique_for_cosmological_parameter_estimation  
> **username_1**: How is that relevant for the papers that you cite in your post above...?  
> **username_0**: @username_1 - I think it is relevant to my comment addressed to you where I asked whether Bayesian Inference and Markov Chain  Monte Carlo sample method were (or could be) applied in analysis of the data obtained by Sahu at al and by Jessica Lu at al ... You claim that Bayesian Inference and Markov Chain  Monte Carlo sample method are not applicable for microlensing research... I think that I found counterexamples and I presented those for your kind attention...  
> **username_1**: The paper you referenced in your previous comment is about cosmological parameter estimation. I don't see how it's about microlensing of black holes. The Sahu and Lu papers were not using Bayesian parameter estimation. Read the Sahu paper, they explain the theory of their computations pretty well.  
> **username_0**: @username_1 Did you look in the same comment of mine at the pdf file featuring research titled "Bayesian modelling of gravitational microlensing events"?  
> **username_1**: No I don't see that comment, I see your comment that links to this article: Fast and reliable Markov chain Monte Carlo technique for cosmological parameter estimation https://www.researchgate.net/publication/227651814_Fast_and_reliable_Markov_chain_Monte_Carlo_technique_for_cosmological_parameter_estimation  
> **username_0**: @username_1 Bartolic_-_ScotDIST_conference_talk.pdf  

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## 0 answers

