Related papers: Decoupling between gravitationally bounded systems…
A positive observational proof suggests that most galaxies contain a central supermassive black hole (SMBH) with mass in the range of $10^6M_\odot$ $-$ $10^{10}M_\odot$. It is suggested that the mass of SMBHs is proportionally related to…
The current expansion of the Universe has been observed to be accelerating, and the widely accepted spatially-flat concordance model of general relativistic cosmology attributes this phenomenon to a constant dark energy, a cosmological…
The accelerated expansion of the Universe is impressively well described by a cosmological constant. However, the observed value of the cosmological constant is much smaller than expected based on quantum field theories. Recent efforts to…
The observed super-massive black hole (SMBH) mass -- galaxy velocity dispersion ($M_{\rm cmo} - \sigma$) correlation, and the similar correlation for nuclear star clusters, may be established when winds/outflows from the CMO ("central…
Most elliptical galaxies contain central black holes, whose masses scale proportionally to the observed central velocity dispersions of the host galaxies according to the so-called Mbh-sigma relation. Here we discuss some consequences that…
Observations of massive galaxies at low redshift have revealed approximately linear scaling relations between the mass of a supermassive black hole (SMBH) and properties of its host galaxy. How these scaling relations evolve with redshift…
Many observed globular clusters (GCs) seem to show a central overabundance of mass whose nature has not yet fully understood. Indeed, it is not clear whether it is due to a central intermediate mass black hole (IMBH) or to a massive stellar…
Supermassive black holes (SMBHs) are tiny in comparison to the galaxies they inhabit, yet they manage to influence and coevolve along with their hosts. Evidence of this mutual development is observed in the structure and dynamics of…
The last decade has witnessed significant progress in our understanding of the growth of super-massive black holes (SMBHs). It is now clear that an Active Galactic Nucleus (AGN: the observed manifestation of a growing SMBH) is an "event"…
Time evolution of a black hole lattice universe is simulated. The vacuum Einstein equations in a cubic box with a black hole at the origin are numerically solved with periodic boundary conditions on all pairs of opposite faces. Defining…
Motivated by the question of how generic inflation is, I study the time-evolution of topological surfaces in an inhomogeneous cosmology with positive cosmological constant $\Lambda$. If matter fields satisfy the Weak Energy Condition,…
The exactly solvable scalar hairy black hole model (originated from the modern high-energy theory) is proposed. It turns out that the existence of black holes (BH) is strongly correlated to global scalar field, in a sense that they mutually…
A scalar field non-minimally coupled to certain geometric [or matter] invariants which are sourced by [electro]vacuum black holes (BHs) may spontaneously grow around the latter, due to a tachyonic instability. This process is expected to…
The Eddington ratio ($\lambda_{\rm Edd}$) of supermassive black holes (SMBHs) is a fundamental parameter that governs the cosmic growth of SMBHs. Although gas mass accretion onto SMBHs is sustained when they are surrounded by large amounts…
The new dynamical theory of space is further confirmed by showing that the black hole masses M_BH in 19 spherical star systems, from globular clusters to galaxies with masses M, satisfy the prediction that M_BH=(alpha/2)M, where alpha is…
The center of our Galaxy is known to host a massive compact object, Sgr A$^*$, which is commonly considered as a super-massive black hole of $\sim 4\times 10^6$ M$_\odot$. It is surrounded by a dense and massive nuclear star cluster, with a…
The cosmological evolution of primordial black holes (PBHs) is considered. A comprehensive view of the accretion and evaporation histories of PBHs across the entire cosmic history is presented, with focus on the critical mass holes. The…
The accelerated expansion of the universe is a rather established fact in cosmology and many different models have been proposed as a viable explanation. Many of these models are based on the standard general relativistic framework of…
The discovery of accelerated cosmic expansion implies that, in addition to the attractive gravity of matter, there exists in our universe some other form of energy (dark energy or cosmological constant) producing a repulsive force. The…
The growth of black holes (BHs) in disk galaxies lacking classical bulges, which implies an absence of significant mergers, appears to be driven by secular processes. Short bars of sub-kiloparsec radius have been hypothesized to be an…