Detectability of a phantom-like braneworld model with the integrated Sachs-Wolfe effect

TL;DR

This paper investigates a braneworld cosmological model exhibiting phantom-like behavior caused by large-scale gravity modifications, and demonstrates that the integrated Sachs-Wolfe effect can distinguish it from standard models.

Contribution

It introduces a large-scale modified gravity braneworld model and shows that the integrated Sachs-Wolfe effect can effectively test and differentiate it from other cosmological models.

Findings

Geometrical tests are insufficient to rule out significant gravity modifications.

The integrated Sachs-Wolfe effect can break degeneracies in model parameters.

Large-scale structure formation tests are crucial for model validation.

Abstract

We study a braneworld model in which a phantom-like behaviour occurs with only cold dark matter and a cosmological constant, due to a large distance modification of gravity. With the addition of curvature, the geometrical tests are not strict enough to rule out models in which gravity is modified significantly on large scales. We show that this degeneracy in the parameter space is broken by the structure formation tests, such as the integrated Sachs-Wolfe effect, which can probe general relativity on large scales.