Testing the DGP model with gravitational lensing statistics

TL;DR

This paper tests the DGP braneworld gravity model against gravitational lensing data, finding it compatible with observations and constraining its parameters, but not conclusively ruling out different curvature scenarios.

Contribution

It provides observational constraints on the DGP model using gravitational lensing statistics, highlighting its viability across a range of parameters.

Findings

Large parameter space of DGP model agrees with lensing data.

Maximum likelihood at .30 for \u03a9_m in flat universe.

Likelihood peaks near .29, .12 when curvature is relaxed.

Abstract

The self-accelerating braneworld model (DGP) seems to provide a simple alternative to the the standard $\Lambda$CDM cosmology to explain the current cosmic acceleration, which is strongly indicated by measurements of Type Ia supernovae, as well as other concordant observations. In this work, we investigate observational constraints on this scenario from gravitational lensing statistics using the Cosmic Lens All-Sky Survey (CLASS) lensing sample. We show that a large parameter space of the DGP model is in good agreement with this radio source gravitational lensing sample. In the flat case, $\Omega_\mathrm{K}=0$, the likelihood is maximized, ${\cal L}={\cal L_\mathrm{max}}$, for $\1 = 0.30_{-0.11}^{+0.19}$. If we relax the prior on $\Omega_\mathrm{K}$, the likelihood peaks at $\{\1,\2 \} \simeq \{0.29, 0.12\}$, just slightly in the region of open models. However the confidence contours are pretty elongated so that we can not discard either close or flat or open models