Exploring Dark Energy with Next-Generation Photometric Redshift Surveys

TL;DR

Next-generation photometric redshift surveys will significantly advance dark energy research by providing high-precision, multiwavelength data to address cosmic acceleration, despite challenges in controlling systematics.

Contribution

This paper discusses the potential of wide-deep multiwavelength photometric surveys for dark energy studies and provides quantitative predictions for a large-scale Stage 4 survey.

Findings

High statistical power of upcoming surveys enhances dark energy constraints

Accurate understanding of observables and systematics is crucial

Quantitative predictions for a 20000 sq. deg. survey are presented

Abstract

The coming decade will be an exciting period for dark energy research, during which astronomers will address the question of what drives the accelerated cosmic expansion as first revealed by type Ia supernova (SN) distances, and confirmed by later observations. The mystery of dark energy poses a challenge of such magnitude that, as stated by the Dark Energy Task Force (DETF), "nothing short of a revolution in our understanding of fundamental physics will be required to achieve a full understanding of the cosmic acceleration." The lack of multiple complementary precision observations is a major obstacle in developing lines of attack for dark energy theory. This lack is precisely what next-generation surveys will address via the powerful techniques of weak lensing (WL) and baryon acoustic oscillations (BAO) -- galaxy correlations more generally -- in addition to SNe, cluster counts, and other probes of geometry and growth of structure. Because of their unprecedented statistical power, these surveys demand an accurate understanding of the observables and tight control of systematics. This white paper highlights the opportunities, approaches, prospects, and challenges relevant to dark energy studies with wide-deep multiwavelength photometric redshift surveys. Quantitative predictions are presented for a 20000 sq. deg. ground-based 6-band (ugrizy) survey with 5-sigma depth of r~27.5, i.e., a Stage 4 survey as defined by the DETF.