We study the primordial spectra and the gravitational-wave background (GWB) of three
models of semi-classical, quantum or string gravity where the big bang is replaced by a …

A bstract We explore a dual scenario of generalized inflation and bounce cosmologies,
producing a scale-invariant curvature perturbation spectrum. Bayesian analysis with pulsar …

A bstract We discuss the possibility of entanglement islands in cosmological spacetimes with
a general perfect fluid with an equation of state w. We find that flat universes with time …

Popular wisdom suggests that measuring the tensor to scalar ratio r on CMB scales is a"
proof of inflation" since one generic prediction is a scale-invariant tensor spectrum while …

We consider the Multiverse as an ensemble of universes. Using standard statistical physics
analysis we get that the Cosmological Constant (CC) is exponentially small. The small and …

These lecture notes introduce the reader to the hot big bang model, cosmological
perturbations, gravitational waves, the cosmic microwave background, inflation, the …

We introduce a set of generic conditions for the slow contracting Universe and for a
narrowed-down category of models called fast-roll models. We present general conditions …

We study the primordial spectra and the gravitational-wave background (GWB) of three
models of semi-classical, quantum or string gravity where the big bang is replaced by a …