In the past decade, a consensus has emerged regarding the nature of classical Be stars:
They are very rapidly rotating main sequence B stars, which, through a still unknown, but …

This review covers the main aspects of black hole accretion disk theory. We begin with the
view that one of the main goals of the theory is to better understand the nature of black holes …

The astrophysical origin of gravitational wave (GW) events discovered by LIGO/VIRGO
remains an outstanding puzzle. In active galactic nuclei (AGNs), compact-object binaries …

Abstract The Laser Interferometer Gravitational-wave Observatory (LIGO) found direct
evidence for double black hole binaries emitting gravitational waves. Galactic nuclei are …

Black hole (BH) accretion flows and jets are qualitatively affected by the presence of ordered
magnetic fields. We study fully 3D global general relativistic magnetohydrodynamic (MHD) …

Circumstellar disks of planetary debris are now known or suspected to closely orbit
hundreds of white dwarf stars. To date, both data and theory support disks that are entirely …

Context. With the high number of extrasolar planets discovered by now, it has become
possible to use the properties of this planetary population to constrain theoretical formation …

Atmospheric xenon is strongly mass fractionated, the result of a process that apparently
continued through the Archean and perhaps beyond. Previous models that explain Xe …

I review the basics of the disc instability model (DIM) for dwarf novae and soft-X-ray
transients and its most recent developments, as well as the current limitations of the model …

Feedback from energy liberated by gas accretion on to black holes (BHs) is an attractive
mechanism to explain the exponential cut-off at the massive end of the galaxy stellar mass …