Title: General Constraints on Primordial Isocurvature from the Cosmic Microwave Background and Pulsar Timing Arrays

Speaker: Professor Peizhi Du (University of Science and Technology of China)

Time: 10:00am, May 19, 2026

Location: 3-402, PMO Xianlin Campus

Abstract: The standard cosmological model (ΛCDM model) assumes adiabatic initial conditions for primordial density perturbations. However, many new physics scenarios can deviate from this assumption and generate isocurvature perturbations across a wide range of scales. In this talk, I will present general constraints on large-scale isocurvature (between 10^-4 Mpc^-1 and 10^-1 Mpc^-1) from observation of the Cosmic Microwave Background. Moreover, Pulsar Timing Arrays set stringent limits on isocurvature around 10^6 Mpc^-1 via isocurvature induced gravitational waves.