Many aspects of the early universe are currently probed through the cosmic microwave background. Due to theoretical developments and an increase in survey sensitivity, these measurements can now be complemented by large-scale structure observations. In this talk, I will advocate the spectrum of baryon acoustic oscillations (BAO) as a new observable for early universe cosmology beyond its use as a standard ruler. I will present the first measurement of the cosmic neutrino background as imprinted in the BAO spectrum of galaxy clustering obtained by the Baryon Oscillation Spectroscopic Survey (BOSS). Moreover, I will discuss a novel search for oscillatory features of the primordial power spectrum in the same observable.
Benjamin Wallisch is currently a postdoctoral member at the Institute for Advanced Study and a postdoctoral scholar at the University of California, San Diego. He obtained his doctorate in theoretical physics at the University of Cambridge (2018) after completing a Bachelor of Science at the Ruprecht-Karls-University Heidelberg (2012) and obtaining Master's degrees at these institutions (2013 and 2014). His research focuses on cosmological probes of fundamental physics, both within the Standard Model and beyond.
More details on Benjamin's research can be found here.