A Simple, Exact Formulation of Number Counts in the Geodesic-Light-Cone Gauge

Abstract

In this article, we compare different formulations of the number count prescription using the convenient formalism of the Geodesic-Light-Cone gauge. We then find a simple, exact, and very general expression of such a prescription which is suitable for generalised applications.

Keywords

• observational cosmology
• covariant averages of astrophysical variables
• light cone gauge