TY - JOUR
T1 - Revisiting string-inspired running-vacuum models under the lens of light primordial black holes
AU - Mavromatos, Nikolaos
N1 - Publisher Copyright:
© 2024 American Physical Society.
PY - 2024/6/26
Y1 - 2024/6/26
N2 - Light primordial black holes (PBHs) with masses MPBH<109 g can interestingly dominate the Universe's energy budget and give rise to early matter-dominated (eMD) eras before big bang nucleosyntesis (BBN). During this eMD era, one is met with an abundant production of induced gravitational waves (GWs) serving as a portal to constrain the underlying theory of gravity. In this work, we study this type of induced GWs within the context of string-inspired running-vaccuum models (StRVMs), which, when expanded around de Sitter backgrounds, include logarithmic corrections of the space-time curvature. In particular, we discuss in detail the effects of StRVMs on the source as well as on the propagation of these PBH-induced GWs. Remarkably, under the assumption that the logarithmic terms represent quantum gravity corrections in the PBH era, we show that GW overproduction can be avoided if one assumes a coefficient of these logarithmic corrections that is much larger than the square of the reduced Planck mass. The latter cannot characterize quantum gravity corrections, though, prompting the need for revision of the quantization of StRVMs in different than de Sitter backgrounds, such as those characterizing PBH-driven eMD eras. This nontrivial result suggests the importance of light PBHs as probes of new physics.
AB - Light primordial black holes (PBHs) with masses MPBH<109 g can interestingly dominate the Universe's energy budget and give rise to early matter-dominated (eMD) eras before big bang nucleosyntesis (BBN). During this eMD era, one is met with an abundant production of induced gravitational waves (GWs) serving as a portal to constrain the underlying theory of gravity. In this work, we study this type of induced GWs within the context of string-inspired running-vaccuum models (StRVMs), which, when expanded around de Sitter backgrounds, include logarithmic corrections of the space-time curvature. In particular, we discuss in detail the effects of StRVMs on the source as well as on the propagation of these PBH-induced GWs. Remarkably, under the assumption that the logarithmic terms represent quantum gravity corrections in the PBH era, we show that GW overproduction can be avoided if one assumes a coefficient of these logarithmic corrections that is much larger than the square of the reduced Planck mass. The latter cannot characterize quantum gravity corrections, though, prompting the need for revision of the quantization of StRVMs in different than de Sitter backgrounds, such as those characterizing PBH-driven eMD eras. This nontrivial result suggests the importance of light PBHs as probes of new physics.
UR - http://www.scopus.com/inward/record.url?scp=85199564311&partnerID=8YFLogxK
U2 - 10.1103/PhysRevD.110.024055
DO - 10.1103/PhysRevD.110.024055
M3 - Article
SN - 2470-0029
VL - 110
JO - Physical Review D
JF - Physical Review D
IS - 2
M1 - 024055
ER -