Speaker
Description
In this talk we present "Lukewarm Inflation", a concrete particle physics model with parametrically low reheating temperatures that can naturally generate a parametrically large, broad, nearly-flat enhancement of the primordial curvature power spectrum. In the case of reheating temperatures $T_R\sim5$ TeV, this simultaneously produces planet-mass primordial black holes and scalar-induced gravitational waves consistent with the nanohertz frequency range, possibly within reach of present and future pulsar timing arrays (PTAs). Furthermore, for $T_R\lesssim 1$ GeV, the late-stage inflationary epoch efficiently dilutes primordial relics, opening a viable window for the QCD axion with a GUT-scale decay constant and $\theta_i \sim 1$ to account for part or all of the observed dark matter abundance.