Re:Is dark matter made of primordial black holes?
by Semirhage on Saturday April 21, 2018 @01:25PM
(#16892296)
It isn’t totally discredited, but the constraints on it make it exceedingly unlikely. Against it:
No gamma ray signals as hoped/expected from evaporating PBH’s.
LIGO is not seeing PBH mergers at a rate that would support the numbers required.
Micro lensing studies don’t support it.
Is it’s possible, but it’s much less likely than other theories which allow for less fine tuning of parameters.
There’s a very good graphic that shows what I’m talking about. https://astrobites.org/wp-content/uploads/2017/08/constraint...
From: https://astrobites.org/2017/08/31/could-dark-matter-be-black...
Re:Is dark matter made of primordial black holes?
by perl4ever on Saturday April 21, 2018 @05:21PM
(#16893511)
The articles I read about LIGO detecting collisions between black holes said they were medium sized, meaning several solar masses. I kind of assumed that they wouldn't be able to detect anything orders of magnitude less than solar mass. Is that not correct?
As a non-astrophysicist, just scanning the wikipedia entry [1] it appears to me that gravitational microlensing studies must be fiendishly difficult, you probably need massive amounts of data and of compute power to get to highly confident conclusions. Is my impression accurate?
If that is so, than the MACHO theory should not be discredited that quickly. It is after all the only theory that does not require any new physics in order to explain the missing mass.
[1] https://en.m.wikipedia.org/wiki/Gravitational_microlensing