Large scale structure and ISW effect in decaying vacuum cosmology

TL;DR

This paper investigates large scale structure formation and the ISW effect within decaying vacuum cosmologies, highlighting subtle differences from standard models that could be tested with future observations.

Contribution

It provides a detailed analysis of the gravitational potential evolution and CMB-LSS cross-correlation in $ ext{"Lambda(t)}$CDM models, including baryonic effects previously neglected.

Findings

Both models agree with current data

Decaying vacuum model predicts a slightly higher ISW signal

Future data could distinguish between models

Abstract

The concordance particle creation model - a class of $\Lambda(t)$CDM cosmologies - is studied using large scale structure (LSS) formation, with particular attention to the integrated Sachs-Wolfe (ISW) effect. The evolution of the gravitational potential and the amplitude of the cross-correlation of the cosmic microwave background (CMB) signal with LSS surveys are calculated in detail. We properly include in our analysis the peculiarities involving the baryonic dynamics of the $\Lambda(t)$CDM model which were not included in previous works. Although both the $\Lambda(t)$CDM and the standard cosmology are in agreement with available data for the CMB-LSS correlation, the former presents a slightly higher signal which can be identified with future data.