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RE: Primordial killers - excluding common dark matter with black holes

in #steemstem5 years ago

@lemouth,

So, gamma-rays are only considered to be a byproduct of WIMP annihilation if they are undetectable, and, therefore, possible to exclude from data?

Forgive me for this possibly mad question. I was very happy with my understanding until I read:

observing a handful of primordial black hole could potentially entirely rule out the WIMP hypothesis, as this would imply the existence of experimentally-excluded gamma rays.

I need some iced-tea now! :P

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Hey Abi! Thanks for passing by (and for this first comment to my post)!

So, gamma-rays are only considered to be a byproduct of WIMP annihilation if they are undetectable, and, therefore, possible to exclude from data?

There are many ways to generate gamma rays in the universe. Dark matter annihilation is one of them.

The point here is that when induced by WIMP annihilation, gamma-ray production has specific properties that could be observed. But we have not observed them. Consequently, such a production mechanism can only occur with a tiny suppressed rate (connected to the y-axis of the last figure).

To rephrase what I said::

  1. Primordial black hole could be dark matter, but under the condition that we have a second dark matter particle.
  2. We assume that this second dark matter particle is a WIMP.
  3. In this case, it has been demonstrated that WIMPs generate many special gamma rays that should have been observed.
  4. We didn't observe those gamma rays.
  5. If WIMP and back hole dark matter coexist, then we have huge constraints on WIMPs as they would generate something unobserved. In other words, the value of the parameter displayed on the y-axis of the last figure has to be small enough to suppress this gamma ray production.

is it clearer?

such a production mechanism can only occur with a tiny suppressed rate (connected to the y-axis of the last figure).

Ok, ok, ok! That’s better.

The numbered list cleared all my doubts and confusion 😃 I got a bit confused today ! Thank you for taking the time to explain things further @lemouth. I truly appreciate it!

Bye for now & happy weekend for the family! ☀️

I am happy this clarified!

Enjoy your week-end as well! Here, it seems fall is starting to really be there... It is coldish (so perfect for construction and gardening) :)