We briefly describe an exact formalism, based on the threshold statistics on the compaction function, for the computation of the abundance of primordial black holes in the presence of local non-Gaussianity (NGs) in the curvature perturbation field with a completely generic functional form. As NGs modify the amplitude of perturbations necessary to produce a given PBH abundance, modeling these...
The gravitational wave (GW) interferometers LISA and ET are expected to be functional in the next decade(s), possibly around the same time. They will operate over different frequency ranges, with similar integrated sensitivities to the amplitude of a stochastic GW background (SGWB). We investigate the synergies between these two detectors, in terms of a multi-band detection of a cosmological...
In this talk, I will review recent developments in the topic of cosmological phase transitions. I will focus on the description of the thermodynamics of the phase transition and the dynamics of bubbles, but I will also explain the implications for the produced gravitational-wave signals and their observability prospects.
I will present numerical results of strong phase transitions using the so-called Higgsless approach and recent theoretical developments to describe the GW production extending the stationary UETC assumption for sound waves to a locally stationary UETC that allows us to describe decaying sources of gravitational waves. The source of GWs corresponding to compressional motion (sound waves in...
We calculate the gravitational wave power spectrum from sound waves in a cosmological first order phase transition in the unexplored regime of large bubbles, by which we mean that the mean bubble spacing $R_*$ is a non-negligible fraction of the Hubble length $\mathcal{H}_*^{-1}$, i.e. $R_*\mathcal{H}_* \lesssim \mathcal{O}(1)$. Since the amplitude of the gravitational wave signal increases...
Cosmological first-order phase transitions may have generated a gravitational wave background observable with LISA, offering a unique probe of beyond-Standard-Model physics. A crucial step in predicting this background is the reliable computation of bubble nucleation rates. In this talk, I will give an overview of recent advancements in perturbative high-temperature nucleation rate...
Among all the possible candidates for Dark Matter, one appealing example is a population of Primordial Black Holes, which could have been borne by various processes in the early stages of the Universe. In this talk, I will investigate the formation of such objects as the result of the collapse of energy density fluctuations originating from supercooled first-order phase transitions. I will...
A gravitational wave background from a first order phase transition at the electroweak scale may be observable with future detectors such as LISA. While the Standard Model does not predict a first order phase transition, these occur in many extended scenarios. Therefore, detecting a stochastic gravitational wave background could point to new physics, while a null detection could constrain or...
