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 …

Recent cosmological observations suggest the existence of a positive cosmological constant
Λ with the magnitude Λ (Gℏ/c3)≈ 10− 123. This review discusses several aspects of the …

General relativity (GR) was proven via the direct detection of gravitational waves from the
mergers of the binary black holes and binary neutron stars by the advanced LIGO and …

The universe is magnetized on all scales probed so far. On the largest scales, galaxies and
galaxy clusters host magnetic fields at the micro Gauss level coherent on scales up to ten …

Multiwavelength observations indicate that some starburst galaxies show a dominant
nonthermal contribution from their central region. These active galactic nuclei (AGN) …

We study the rate at which gas accretes on to galaxies and haloes and investigate whether
the accreted gas was shocked to high temperatures before reaching a galaxy. For this …

Supermassive black hole binaries (SMBHBs) in galactic nuclei are thought to be a common
by-product of major galaxy mergers. We use simple disk models for the circumbinary gas …

Current cosmological observations show a strong signature of the existence of a dark
energy component with negative pressure. The most obvious candidate for this dark energy …

The formation of large-scale structure is independent of the nature of the cold dark matter
(CDM), however the fate of very small-scale inhomogeneities depends on the microphysics …

Context. Supermassive stars and quasi-stars (massive stars with a central black hole) are
both considered as potential progenitors for the formation of supermassive black holes. They …