In the inflation without inflaton scenario (IWI) there are no free parameters as the energy scale for inflation is determined by the observed value of the initial scalar perturbations by the cosmic microwave background. In this talk we will describe the scenario and show new advances in the computation of observational signals like non-gaussianity
Motivated by many interesting features present in braneworld cosmology and higher-dimensional gravity, we reexamine foundational concepts and processes that have previously been studied in this framework, such as gravitational collapse, black hole accretion and Hawking emission. In this talk we delve into these processes in a cosmological context and into the possibility of the totality of...
Gravitational-wave astronomy has entered a mature observational era, with the latest Gravitational-Wave Transient Catalog (GWTC-4) reporting nearly a hundred new compact binary coalescences. These results rely critically on accurate waveform models to infer source properties and test general relativity. I will begin by reviewing how waveform models underpin current gravitational-wave analyses...
Gravitational waves (GWs) provide a unique probe of the early universe, as they can travel almost freely from their generation to the present. I will discuss two cosmological GW sources: primordial GWs from quantum fluctuations during inflation and scalar-induced GWs (SIGWs) produced by curvature perturbations at horizon reentry. Both can reveal the universe’s thermal history. In particular, I...
