Primordial Black Holes and Cosmological Phase Transitions Report ...

PBHs and Cosmological Phase Transitions 104
cs 2
0.3
0.25
0.2
0.15
b
a
0.25 0.5 0.75 1 1.25 1.5 1.75 2
T MeV
Figure 42: The sound speed c2 s (T ) during the electron–positron annihilation
with Tc = 1 MeV and: (a) ∆T =0.115Tc (reduction of 20%), (b) ∆T =0.276Tc
(reduction of 10%).
cs 2
0.3
0.25
0.2
0.15
b
a
-0.25 0 0.25 0.5 0.75 1 1.25 1.5
Log 10t1s
Figure 43: The sound speed c2 s (t) during the electron–positron annihilation with
Tc = 1 MeV and: (a) ∆T =0.115Tc (reduction of 20%), (b) ∆T =0.276Tc
(reduction of 10%).