A Concise Introduction to Perturbation Theory in Cosmology
arXiv:0804.3276 · doi:10.1088/0264-9381/25/19/193001
Abstract
We give a concise, self-contained introduction to perturbation theory in cosmology at linear and second order, striking a balance between mathematical rigour and usability. In particular we discuss gauge issues and the active and passive approach to calculating gauge transformations. We also construct gauge-invariant variables, including the second order tensor perturbation on uniform curvature hypersurfaces.
revtex4, 16 pages, 3 figures; v2: minor changes, typos corrected, reference added, version accepted by CQG