Future questions for cosmology

This review attempts to summarize recent progress in cosmology, and outline some of the main open questions for the forthcoming decade. Following the year-3 WMAP results, the basic ΛCDM model seems better established than ever, with the exciting addition of a rejection of the n = 1 scale-invariant spectrum. It is argued that this alone is insufficient to constitute proof that inflation occurred, and B-mode CMB polarization must continue to be a prime target. Structure formation within the standard model is well understood in principle, but significant open issues remain where the modelling of galaxy formation is concerned. A major item for the future will be attempting to detect dynamical vacuum energy beyond a simple cosmological constant. However, the overall level of the vacuum density remains poorly understood; anthropic reasoning is probably required to make sense of what we see.