Constraining the EoR model parameters with the 21cm bispectrum

TL;DR

This paper uses Fisher analysis to show that including the 21cm bispectrum significantly improves constraints on Epoch of Reionization parameters over the power spectrum alone, especially when combined.

Contribution

It demonstrates that the 21cm bispectrum provides tighter constraints and breaks parameter degeneracies in EoR models compared to using the power spectrum alone.

Findings

Bispectrum constrains EoR parameters more tightly than power spectrum.

Combining bispectrum with power spectrum breaks parameter degeneracies.

Assuming perfect foreground removal, bispectrum enhances EoR parameter estimation.

Abstract

We perform a Fisher analysis to estimate the expected constraints on the Epoch of Reionization (EoR) model parameters (i.e., minimum virial temperature, the ionizing efficiency and the mean free path of ionizing photons) taking into account the thermal noise of the exisitting telescopes, MWA and LOFAR. We consider how the inclusion of the 21cm bispectrum improves the constraints compared to using the power spectrum alone. Assuming that we perfectly remove the foreground, we found that the bispectrum, which is calculated by the 21cmFAST code, can constrain the EoR model parameters more tightly than the power spectrum since the bispectrum is more sensitive to the EoR model parameters than the power spectrum. We also found that degeneracy between the EoR model parameters can be broken by combining the bispectrum with the power spectrum.