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Brane world models have shown to be promising to understand the late cosmic acceleration, in particular because such acceleration can be naturally derived, mimicking the dark energy behaviour just with a five dimensional geometry. In this paper we present a strong lensing joint analysis using a compilation of early-type galaxies acting as a lenses, united with the power of the well studied strong lensing galaxy cluster Abell 1689. We use the strong lensing constraints to investigate a brane model with variable brane tension as a function of the redshift. In our joint analysis we found a value n = 7. 8 - 0.5 + 0.9 , for the exponent related to the brane tension, showing that n deviates from a Cosmological Constant (CC) scenario (n=6). We obtain a value for the deceleration parameter, q(z) today, q (0) = - 1. 2 - 0.8 + 0.6 , and a transition redshift, z t = 0.60 ± 0.06 (when the Universe change from an decelerated phase to an accelerated one). These results are in contrast with previous work that favors CC scenario, nevertheless our lensing analysis is in agreement with a formerly reported conclusion suggesting that the variable brane tension model is able to source a late cosmic acceleration without an extra fluid as in the standard one. [ABSTRACT FROM AUTHOR]

Inspired by a new compilation of strong-lensing systems, which consist of 204 points in the redshift range 0.0625 < z l < 0.958 for the lens and 0.196 < z s < 3.595 for the source, we constrain three models that generate a late cosmic acceleration: the ω -cold dark matter model, the Chevallier–Polarski–Linder, and the Jassal–Bagla–Padmanabhan parametrizations. Our compilation contains only those systems with early-type galaxies acting as lenses, with spectroscopically measured stellar velocity dispersions, estimated Einstein radius, and both the lens and source redshifts. We assume an axially symmetric mass distribution in the lens equation, using a correction to alleviate differences between the measured velocity dispersion (σ) and the dark matter halo velocity dispersion (σ DM) as well as other systematic errors that may affect the measurements. We have considered different subsamples to constrain the cosmological parameters of each model. Additionally, we generate a mock data of SLS to asses the impact of the chosen mass profile on the accuracy of Einstein radius estimation. Our results show that cosmological constraints are very sensitive to the selected data: Some cases show convergence problems in the estimation of cosmological parameters (e.g. systems with observed distance ratio D obs < 0.5), others show high values for the χ 2 function (e.g. systems with a lens equation D obs > 1 or high velocity dispersion σ > 276 km s−1). However, we obtained a fiduciary sample with 143 systems, which improves the constraints on each tested cosmological model. [ABSTRACT FROM AUTHOR]

Motivated by an updated compilation of observational Hubble data (OHD) that consist of 51 points in the redshift range of 0.07 < z < 2.36, we study an interesting model known as Cardassian that drives the late cosmic acceleration without a dark energy component. Our compilation contains 31 data points measured with the differential age method by Jimenez & Loeb (2002), and 20 data points obtained from clustering of galaxies. We focus on two modified Friedmann equations: the original Cardassian (OC) expansion and the modified polytropic Cardassian (MPC). The dimensionless Hubble, E(z), and the deceleration parameter, q(z), are revisited in order to constrain the OC and MPC free parameters, first with the OHD and then contrasted with recent observations of type Ia supernova (SN Ia) using the compressed and full joint-light-analysis (JLA) samples (Betoule et al.). We also perform a joint analysis using the combination OHD plus compressed JLA. Our results show that the OC and MPCmodels are in agreement with the standard cosmology and naturally introduce a cosmological-constant-like extra term in the canonical Friedmann equation with the capability of accelerating the Universe without dark energy. [ABSTRACT FROM AUTHOR]