Quantum gravity is expected to be necessary in order to understand situations in which
classical general relativity breaks down. In particular in cosmology one has to deal with …

Observations indicate that our universe is characterized by a late-time accelerating phase,
possibly driven by a cosmological constant Λ, with the dimensionless parameter, where …

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 …

Nearly seventy per cent of the energy density in the universe is unclustered and exerts
negative pressure. This conclusion--now supported by numerous observations--poses the …

Recent cosmological observations suggest that nearly seventy per cent of the energy
density in the universe is unclustered and has negative pressure. Several conceptual issues …

We have explicitly demonstrated that scalar coupled Gauss-Bonnet gravity in four
dimensions can have nontrivial effects on the early inflationary stage of our Universe. In …

Kerrr in the title is not a typo. The third “r” stands for regular, in the sense of pathology-free
rotating black hole. We exhibit a long search-for, exact, Kerr-like, solution of the Einstein …

Understanding the emergence of classical behavior from a quantum theory is vital to
establishing the quantum origin for the temperature fluctuations observed in the cosmic …

The numerical consequences of the theory developed in two previous papers are examined
in more detail. In particular, it is shown that the radio source count data can be explained to …

The absence of isotropic singularity in loop quantum cosmology can be understood in an
effective classical description as the Universe exhibiting a big bounce. We show that with a …