Primordial Black Holes and Cosmological Phase Transitions Report ...

PBHs and Cosmological Phase Transitions 191
log 10Βtk
0
-20
-40
-60
-80
n1.48, log 10t1s4
-8 -6 -4 -2
log10 tk
1 s
Figure 104: The fraction of the universe going into PBHs in a universe with a
running–tilt power spectrum when n+ =1.48 and t+ = 10 −4 s. The dark curve
represents the radiation contribution and the maroon line the observational
constraints. The other curves represent the contribution from the QCD phase
transition: Crossover (green), Lattice Fit (magenta) and Bag Model (blue). The
latter two models for the QCD transition are excluded, due to observational
constraints.
log 10Βtk
0
-2.5
-5
-7.5
-10
-12.5
-15
-17.5
n1.52, log 10t1s3
-7 -6 -5 -4 -3 -2 -1 0
log10 tk
1 s
Figure 105: The fraction of the universe going into PBHs in a universe with a
running–tilt power spectrum when n+ =1.52 and t+ = 10 −3 s (see Figure 104
for more details). Whatever the model adopted for the QCD transition this case
must be excluded, due to observational constraints.