Conveners
Early Universe
- Mar Bastero Gil (University of Granada)
Early Universe
- Mar Bastero Gil (University of Granada)
A possible way to generate primordial black holes as candidates for the entirety of dark matter is a large power spectrum of inflationary curvature fluctuations. Recently, questions have been raised regarding the validity of perturbation theory in this context. We compute the one-loop power spectrum in ultra-slow roll inflation, including all relevant interactions for such analysis, along with...
Nowadays, the search for primordial gravitational waves is mainly focused on the parity-odd polarization pattern in the CMB - the B-modes. A correct interpretation of B-mode measurements strongly relies on understanding their production mechanism. One intriguing scenario is gravitational waves generation by gauge fields. The tachyonic amplification of the gauge fields modes during inflation...
Fundamental scale invariance has been proposed as a new theoretical principle beyond renormalizability. Besides its highly predictive power, a scale-invariant formulation of gravity could provide a natural explanation for the long-standing hierarchy problem and interesting applications in cosmology.
We present a globally scale-invariant model of quadratic gravity and study its solutions in a...
Slow first-order phase transitions generate large inhomogeneities that can lead to the formation of primordial black holes (PBHs). We show that the gravitational wave (GW) spectrum then consists of a primary component sourced by bubble collisions and a secondary one induced by large perturbations. The latter gives the dominant peak if $\beta/H_0 < 10$, impacting, in particular, the...
In standard leptogenesis models, the baryon asymmetry is initially produced as a lepton asymmetry via the out of equilibrium decays of the lightest right handed neutrino (RHN).
There are however constraints on the RHN mass that are in tension; the naturalness constraint on the Higgs mass from RHN loop corrections, i.e. the Vissani bound, puts a limit on the RHN mass which is lower than is...
We introduce a novel approach to investigate sectors solely gravitationally coupled, characterized by significant anisotropies. These anisotropies undergo damping through gravitational interactions with the baryon-photon fluid, inducing heating in the process. The resultant injected heat leads to observable distortions in the cosmic microwave background spectrum. We provide analytic estimates...
