The Integrated Bispectrum in Modified Gravity Theories

TL;DR

This paper explores the use of the Integrated Bispectrum as a probe for modified gravity theories, incorporating redshift-space distortions and advanced statistical tools to analyze large-scale structure data.

Contribution

It extends previous IB studies by including redshift-space distortions and develops new methods for analyzing non-Gaussianity in modified gravity models.

Findings

Derived contributions of redshift-space distortions to IB in MG theories

Presented results using Zel'dovich Approximation and projected surveys

Generalized cumulant correlators for halos of different masses

Abstract

Gravity-induced non-Gaussianity can provide important clues to Modified Gravity (MG) Theories. Several recent studies have suggested using the {\it Integrated Bispectrum} (IB) as a probe for squeezed configuration of bispectrum. Extending previous studies on the IB, we include redshift-space distortions to study a class of (parametrised) MG theories that include the string-inspired Dvali, Gabadadze \& Porrati (DGP) model. Various contributions from redshift-space distortions are derived in a transparent manner, and squeezed contributions from these terms are derived separately. Results are obtained using the Zel'dovich Approximation (ZA). Results are also presented for projected surveys (2D). We use the Press-Schechter (PS) and Sheth-Torman (ST) mass functions to compute the IB for collapsed objects that can readily be extended to peak-theory based approaches. The {\em cumulant correlators} (CCs) generalise the ordinary {\em cumulants} and are known to probe collapsed configurations of higher order correlation functions. We generalise the concept of CCs to halos of different masses. We also introduce a generating function based approach to analyse more general non-local biasing models. The Fourier representations of the CCs, the skew-spectrum, or the kurt-spctra are discussed in this context. The results are relevant for the study of the Minkowski Functionals (MF) of collapsed tracers in redshift-space.} \keywords {Cosmology, Large Scale Structure, Modified Theories of Gravity