Speaker
Description
We study whether short-time-scale physics in the early universe can leave visible imprints on later structure formation. In particular, we focus on oscillatory or localized features in the primordial matter power spectrum and ask how they affect the halo mass function. Using excursion set theory with different smoothing window functions, we find that these features can survive as oscillatory or localized changes in halo abundance. This is different from the nonlinear matter power spectrum, where such oscillations are usually smeared by mode mixing. The most promising observational connection is through low-mass halos and high-redshift galaxy probes such as the UV luminosity function. However, the interpretation is still limited by the uncertain mapping between halo mass and galaxy luminosity, as well as by constraints from the CMB and large-scale structure.