5 papers
Bianchi spacetimes as super-curvature modes around isotropic cosmologies
Thiago S. Pereira, Cyril Pitrou
A powerful result in theoretical cosmology states that a subset of anisotropic Bianchi models can be seen as the homogeneous limit of (standard) linear cosmological perturbations.…
Mitigating cosmic variance in the Hellings-Downs curve: a Cosmic Microwave Background analogy
Cyril Pitrou, Giulia Cusin
The Hellings-Downs (HD) correlation, which characterizes the signature of a stochastic gravitational wave background measured via Pulsar Timing Arrays (PTA), is derived using a har…
Measuring anisotropies in the PTA band with cross-correlations
Giulia Cusin, Cyril Pitrou, Martin Pijnenburg +1
The astrophysical gravitational wave background in the nanohertz (nHz) band is expected to be primarily composed of the superposition of signals from binaries of supermassive black…
Precision big bang nucleosynthesis with improved Helium-4 predictions
Cyril Pitrou, Alain Coc, Jean-Philippe Uzan +1
Primordial nucleosynthesis is one of the three historical evidences for the big bang model, together with the expansion of the universe and the cosmic microwave background. Now tha…
Constraints on primordial lepton asymmetries with full neutrino transport
Julien Froustey, Cyril Pitrou
Primordial neutrino-antineutrino asymmetries can be constrained through big-bang nucleosynthesis (BBN) relic abundances and cosmic microwave background (CMB) anisotropies, both obs…