Observational Constraints with Recent Data on the DGP Modified Gravity

摘要: We study one of the simplest covariant modified-gravity models based on Dvali-Gabadadze-Porrati (DGP) brane cosmology, a self-accelerating universe. In this model gravitational leakage into extra dimensions is responsible late-time acceleration. mainly focus effects parameters geometry and age Also we investigate evolution matter density perturbations in modified gravity model, obtain an analytical expression for growth index, f. show that increasing \(\Omega_{r_{c}}\) leads to less contrast δ, also decreases index. give fitting formula index at present time indicate dominant term verifies well-known approximation relation f≃Ωmγ. As observational test, new Supernova Type Ia (SNIa) Gold sample Legacy Survey (SNLS) data, size baryonic acoustic peak from Sloan Digital Sky (SDSS), position CMB observations Cluster Baryon Gas Mass Fraction (gas) are used constrain DGP model. combine previous results with large scale structure formation (LSS) 2dFGRS survey. Finally check consistency compare old cosmological objects universe