Related papers: Observational Constraints on the Common Envelope P…
The shaping of the nebula is currently one of the outstanding unsolved problems in planetary nebula (PN) research. Several mechanisms have been proposed, most of which require a binary companion. However, direct evidence for a binary…
The discrepancy between abundances computed using optical recombination lines (ORLs) and collisionally excited lines (CELs) is a major unresolved problem in nebular astrophysics. We show here that the largest abundance discrepancies are…
The discovery of a giant planet candidate orbiting the white dwarf WD 1856+534 with an orbital period of 1.4 d poses the questions of how the planet reached its current position. We here reconstruct the evolutionary history of the system…
Recent discoveries of gravitational wave sources have advanced our knowledge about the formation of compact object binaries. At present, many questions about the stellar origins of binary neutron stars remain open. We explore the evolution…
I will review some results of observational cosmology which critically cast doubt upon the foundations of the standard cosmology: 1) The redshifts of the galaxies are due to the expansion of the Universe; 2) The cosmic microwave background…
Generalized uncertainty principle and breakdown of the spacetime continuum certainly represent two important results derived of various approaches related to quantum gravity and black hole physics near the well-known Planck scale. The…
The phase diagram of a system constituted of neutrons and $\Lambda$-hyperons in thermal equilibrium is evaluated in the mean-field approximation. It is shown that this simple system exhibits a complex phase diagram with first and second…
We present a new mechanism for the ejection of a common envelope in a massive binary, where the energy source is nuclear energy rather than orbital energy. This can occur during the slow merger of a massive primary with a secondary of 1-3…
Understanding the galaxy in which we live is one of the great intellectual challenges facing modern science. With the advent of high quality observational data, the chemical evolution modeling of our galaxy has been the subject of numerous…
A light bullet is an extremely compressed in space and time wave packet of a few optical cycles, which is formed in the bulk transparent dielectric during femtosecond filamentation under anomalous group velocity dispersion. The effect of a…
Close, compact, hierarchical, multiple stellar systems, i.e., multiples having an outer orbital period from months to a few years, comprise a small, but continuously growing group of the triple and multiple star zoo. Many of them consist of…
Inspired by the recent Kepler discoveries of circumbinary planets orbiting nine close binary stars, we explore the fate of the former as the latter evolve off the main sequence. We combine binary star evolution models with dynamical…
Binary neutron stars (BNSs) are among the most interesting sources for multimessenger studies. A number of recently discovered BNSs in the Milky Way by radio telescopes have added new information to the parameter distribution of the…
Massive stars are usually found in binaries, and binaries with periods less than 10 days may have a preference for near equal component masses. In this paper we investigate the evolution of these binaries all the way to contact and the…
The "Scenario Machine" (a computer code designed for studies of the evolution of close binaries) was used to carry out a population synthesis for a wide range of merging astrophysical objects: main-sequence stars with main-sequence stars;…
The ringdown phase of a black hole formed from the merger of two orbiting black holes is described by means of the close-limit (CL) approximation starting from second-post-Newtonian (2PN) initial conditions. The 2PN metric of point-particle…
Common envelope evolution is a critical but still poorly understood phase in binary evolution. It plays a key role in forming close binaries such as hot subdwarfs, double white dwarfs, X-ray binaries, and double neutron stars. However, its…
We consider the interference of two overlapping ideal Bose-Einstein condensates. The usual description of this phenomenon involves the introduction of a so-called condensate wave functions having a definite phase. We investigate the origin…
We study the merging of massive stars inside a common envelope for binary systems consisting of a red supergiant with a mass of 15-20 Msun and a main-sequence companion of 1-5 Msun. We are particularly interested in the stage when the…
The pattern of isentropes in the vicinity of a first-order phase transition is proposed as a key for a sub-classification. While the confinement--deconfinement transition, conjectured to set in beyond a critical end point in the QCD phase…