Constraining Chaplygin models using diffuse supernova neutrino
  background
  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.
