Liang Dai, Johns Hopkins University, " Conformal Fermi coordinates and the local universe formalism"
KICP Seminar: November 21, 2014 @ 12PM
In an inhomogeneous Universe, the physical effect of long-wavelength perturbation on short distances should be such that short-wavelength perturbations effectively evolve in a modified homogeneous universe. We explicitly construct the so-called conformal Fermi normal coordinates (CFNC) through an expansion around the observer's geodesic, which describe the local spacetime as a quasi-FRW metric and are valid at all times....