Abstract The standard Λ Cold Dark Matter (ΛCDM) cosmological model provides a good
description of a wide range of astrophysical and cosmological data. However, there are a …

The simplest ΛCDM model provides a good fit to a large span of cosmological data but
harbors large areas of phenomenology and ignorance. With the improvement of the number …

Singularities in any physical theory are either remarkable indicators of the unknown
underlying fundamental theory, or indicate a change in the description of the physical reality …

Abstract Recent Baryon Acoustic Oscillation (BAO) measurements released by DESI, when
combined with Cosmic Microwave Background (CMB) data from Planck and two different …

We review in detail a number of approaches that have been adopted to try and explain the
remarkable observation of our accelerating universe. In particular we discuss the arguments …

The universe is smooth on large scales but very inhomogeneous on small scales. Why is the
spacetime on large scales modeled to a good approximation by the Friedmann equations …

We critically examine the state of current constraints on the dark energy (DE) equation of
state (EoS) w. Our study is motivated by the observation that, while broadly consistent with …

In this work we shall investigate the occurrence of future cosmological finite-time
singularities in the dynamical system corresponding to two cosmological theories, namely …

I review the problem of dark energy focussing on cosmological constant as the candidate
and discuss what it tells us regarding the nature of gravity. Section 1 briefly overviews the …

The effective evolution of an inhomogeneous universe model in any theory of gravitation
may be described in terms of spatially averaged variables. In Einstein's theory, restricting …