Institute for Advanced Study Astrophysics Seminar

I will discuss how sound waves racing through the cosmos during the first million years of the Universe provide a robust method for measuring the low-redshift cosmological distance scale and thereby the properties of dark energy. The distance that the sound can travel can be computed to high precision and creates a signature in the late-time clustering of matter that serves as a standard ruler. Galaxy clustering results from the Sloan Digital Sky Survey and SDSS-III reveal this feature and allow us to measure distances to high accuracy, including a new 1% measurement to z=0.57.