Gravitational waves (GWs) were recently detected for the first time. This revolutionary
discovery opens a new way of learning about particle physics through GWs from first-order …

The first generation of stars, often called Population III (or Pop III), form from metal-free
primordial gas at redshifts z∼ 30 and below. They dominate the cosmic star-formation …

The 15 yr pulsar timing data set collected by the North American Nanohertz Observatory for
Gravitational Waves (NANOGrav) shows positive evidence for the presence of a low …

A number of challenges to the standard Λ CDM model have been emerging during the past
few years as the accuracy of cosmological observations improves. In this review we discuss …

We provide a review on the state-of-the-art of gravitational waves induced by primordial
fluctuations, so-called induced gravitational waves. We present the intuitive physics behind …

Gravitational wave (GW) detection in space probes the GW spectrum that is inaccessible
from the Earth. In addition to the LISA project led by the European Space Agency, and the …

The power-law parametrization for the energy density spectrum of gravitational wave (GW)
background is a useful tool to study its physics and origin. While scalar induced secondary …

We study gravitational waves (GWs) induced by non-Gaussian curvature perturbations. We
calculate the density parameter per logarithmic frequency interval, Ω GW (k), given that the …

70 AIM, UMR 7158, CEA/DRF, CNRS, Université Paris Diderot, Irfu/Service d'Astrophysique,
Centre de Saclay, FR-91191 Gif-sur-Yvette, France

The stochastic signal detected by NANOGrav, PPTA, EPTA, and CPTA can be explained by
the scalar-induced gravitational waves. In order to determine the scalar-induced …