Precision cosmology with a combination of wide and deep Sunyaev-Zeldovich cluster surveys

TL;DR

This paper demonstrates that combining wide and deep Sunyaev-Zel'dovich cluster surveys enhances cosmological parameter constraints by breaking degeneracies and recovering information diluted in single surveys.

Contribution

It introduces a wedding cake survey design that optimally combines wide and deep observations to improve cosmological constraints from cluster surveys.

Findings

Combining wide and deep surveys breaks parameter degeneracies.

Variable depth surveys with fewer clusters match the effectiveness of larger single-depth surveys.

Survey design significantly impacts cosmological parameter estimation.

Abstract

We show the advantages of a wedding cake design for Sunyaev-Zel'dovich cluster surveys. We show that by dividing up a cluster survey into a wide and a deep survey, one can essentially recover the cosmological information that would be diluted in a single survey of the same duration due to the uncertainties in our understanding of cluster physics. The parameter degeneracy directions of the deep and wide surveys are slightly different, and combining them breaks these degeneracies effectively. A variable depth survey with a few thousand clusters is as effective at constraining cosmological parameters as a single depth survey with a much larger cluster sample.