Cosmological parameters are dressed

TL;DR

This paper explores how the inhomogeneous geometry of the Universe affects the interpretation of cosmological parameters, distinguishing between 'bare' parameters and 'dressed' parameters influenced by spatial averaging.

Contribution

It introduces a framework to interpret cosmological parameters by accounting for the inhomogeneous geometry, bridging the gap between theoretical models and observationally biased parameters.

Findings

Clarifies the distinction between 'bare' and 'dressed' cosmological parameters.

Provides a method to interpret observational parameters considering inhomogeneities.

Enhances understanding of the averaging problem in relativistic cosmology.

Abstract

In the context of the averaging problem in relativistic cosmology, we provide a key to the interpretation of cosmological parameters by taking into account the actual inhomogeneous geometry of the Universe. We discuss the relation between `bare' cosmological parameters determining the cosmological model, and the parameters interpreted by observers with a ``Friedmannian bias'', which are `dressed' by the smoothed-out geometrical inhomogeneities of the surveyed spatial region.