Francesco Schiavone (Bari University)
Title: Axion-like particles from primordial black holes shining through the Universe
Abstract: We consider a cosmological scenario in which the very early Universe experienced a transient epoch of matter domination due to the formation of a large population of primordial black holes (PBHs) with masses M 10^9 g, that evaporate before Big Bang nucleosynthesis. In this context, Hawking radiation would be a non-thermal mechanism to produce a cosmic background of axion-like particles (ALPs). We assume the minimal scenario in which these ALPs couple only with photons. In the case of ultralight ALPs (m_a 10^ 9 eV) the cosmic magnetic fields might trigger ALP-photon conversions, while for masses m_a 10 eV spontaneous ALP decay in photon pairs would be effective. We investigate the impact of these mechanisms on the cosmic X-ray background, on the excess in X-ray luminosity in Galaxy Clusters, and on the process of cosmic reionization.
Fecha: Jueves 2 de diciembre de 2021
Hora: 12:10
Lugar: Seminario de Física Teórica
L | M | M | J | V | S | D |
---|---|---|---|---|---|---|
|
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
9
|
10
|
11
|
12
|
13
|
14
|
15
|
16
|
17
|
18
|
19
|
20
|
21
|
22
|
23
|
24
|
25
|
26
|
27
|
28
|
29
|
30
|
|
|
|