Why is Universe so dark ?

Abstract

In this presentation prepared for a general audience, we briefly mention the shortcomings of standard model of universe. We then focus on the late time inconsistency of the model dubbed age crisis whose resolution requires the presence of a repulsive effect that could be sourced either by dark energy or by a large scale modification of gravity. By and large, our description is based upon Newtonian cosmology which is simple and elegant despite of its limitations. On heuristic grounds, we explain how a tiny mass of graviton could account for late time cosmic acceleration. We also include a brief discussion on the underlying physics of Type Ia supernovae explosion and the direct confirmation of late time acceleration of Universe by the related observations.

16 pages and 7 figures, expanded version of Vaidya-Roychoudhury endowment award lecture delivered at Shree Shivaji Science College, Nagpur

References in corpus (7)

• Dynamics of dark energy
• Dark energy cosmology: the equivalent description via different theoretical models and cosmography tests
• Dark Energy and the Accelerating Universe
• Resummation of Massive Gravity
• Observational Probes of Cosmic Acceleration
• Approaches to Understanding Cosmic Acceleration
• Mapping the Cosmological Expansion

Cited by in corpus (4)

• Constraints on cosmological parameters in power-law cosmology
• Cosmic acceleration from coupling of baryonic and dark matter components: Analysis and diagnostics
• Cosmic acceleration sourced by modification of gravity without extra degrees of freedom
• Cosmological parametrizations and their scalar field descendents