Executive Summary : | The inhomogeneous universe, as probed by Cosmic Microwave Background (CMB) radiation or surveys of Large-scale structure (Lss), offers a valuable window into the physics of the early universe. The power spectrum of primordial curvature perturbations, seeds of observed CMB anisotropies, is constrained by precise cosmological observations. However, constraints on the primordial power spectrum over smaller scales are weaker, leading to the generation of Primordial Black Holes (PBHs). These scalar perturbations are associated with the generation of induced Gravitational Waves (GWs) at second order in perturbation theory. Over the next two years, researchers plan to explore the origin of induced GWs from various inflation models and their detection. They also aim to reconstruct possible models of inflation from the power spectrum, constrained by the observations of PBHs and induced GWs. They plan to explore more general and diverse models, compute the spectra of sGWB, and reconstruct two field models using various approximation methods. They also plan to modify the Generalised slow Roll approximation technique to calculate the power spectrum and investigate the possibility of constraining single field inflationary models. |