Cosmology with Strong Lensing Systems

Understand

In this paper, we assemble a catalog of 118 strong gravitational lensing systems from SLACS, BELLS, LSD and SL2S surveys and use them to constrain the cosmic equation of state.

• In particular we consider two cases of dark energy phenomenology: $XCDM$ model where dark energy is modeled by a fluid with constant $w$ equation of state parameter and in Chevalier - Polarski - Linder (CPL) parametrization where $w$ is allowed to evolve with redshift: $w(z) = w_0 + w_1 \frac{z}{1+z}$.
• We assume spherically symmetric mass distribution in lensing galaxies, but relax the rigid assumption of SIS model in favor to more general power-law index $\gamma$, also allowing it to evolve with redshifts $\gamma(z)$.
• Our results for the $XCDM$ cosmology show the agreement with values (concerning both $w$ and $\gamma$ parameters) obtained by other authors.