# Constraining Chaplygin models using diffuse supernova neutrino background

## TL;DR

This paper investigates how the diffuse supernova neutrino background can be used to test and constrain different Chaplygin gas cosmological models, highlighting the potential of neutrino flux measurements to distinguish between models.

## Contribution

It introduces a method to use DSNB flux spectra to differentiate and constrain various Chaplygin gas models of the universe.

## Key findings

- DSNB flux spectra are similar to Fermi-Dirac distributions with peaks around 3.80-3.97 MeV.
- The flux spectrum height varies significantly among different CG models.
- Total flux differences can be used to constrain CG model parameters.

## Abstract

In this work, we examine the possibility of using the diffuse supernova neutrino background (DSNB) to test the Chaplygin gas (CG) models of the Universe. With a typical supernova rate $R_{\mathrm{SN}}(z)$ and supernova neutrino spectrum $\mathrm{d} N(E_\nu)/\mathrm{d} E_\nu$, the DSNB flux spectrum $n(E_\nu)$ in three categories of CG models, the generalized CG (GCG), modified CG (MCG) and extended CG (ECG) models, are studied. It is found that generally the flux spectra take a form similar to a Fermi-Dirac distribution with a peak centered around 3.80-3.97 MeV. The spectrum shape and peak positions are primarily determined by $R_{\mathrm{SN}}(z)$ and $\mathrm{d} N(E_\nu)/\mathrm{d} E_\nu$ and only slightly affected by the CG models. However, the height of the spectra in each category of the CG models can vary dramatically for different models, with variances of 13.2%, 23.6% and 14.9% for GCG, MCG and ECG categories respectively. The averaged total flux in each category are also different, with the ECG model average 10.0% and 12.7% higher than that of the GCG and MCG models. These suggest that the DSNB flux spectrum height and total flux can be used to constrain the CG model parameters, and if the measured to a sub-10% accuracy, might be used to rule out some models.