Related papers: An application of the tensor virial theorem to hol…
According to the Virial Theorem, all gravitational systems in equilibrium sit on a plane in the 3D parameter space defined by their mass, size and second moment of the velocity tensor. While these quantities cannot be directly observed,…
A general theory of homeoidally striated density profiles where no divergence occurs, is adapted to cuspy density profiles, with a suitable choice of the scaling density and the scaling radius. A general formulation of some physical…
The single vortex problem in a strongly correlated bosonic system is investigated self-consistently within the mean-field theory of the Bose-Hubbard model. Near the superfluid-Mott transition, the vortex core has a tendency toward the…
We summarise a selection of results on the inviscid limit of the stochastic Burgers equation emphasising geometric properties of the caustic, Maxwell set and Hamilton-Jacobi level surfaces and relating these results to a discussion of…
Vector-tensor theories beyond General Relativity have widely been studied in the context of ultraviolet completion of gravity, endowing a mass to the graviton and explaining dark energy phenomena. We here construct rotating black hole…
Turbulent convection models are thought to be good tools to deal with the convective overshooting in the stellar interior. However, they are too complex to be applied in calculations of stellar structure and evolution. In order to…
We argue that the velocity dispersions and masses of galactic bulges and spheroids are byproducts of the feedback that regulates rapid black hole growth in protogalaxies. We suggest that the feedback energy liberated by accretion must pass…
In massive objects, such as galaxy clusters, the turbulent velocity dispersion, $\sigma_\mathrm{turb}$, is tightly correlated to both the object mass, $M$, and the thermal energy. Here, we investigate whether these scaling laws extend to…
The mass of the Galactic bulge, $M_B$, is estimated from the tensor virial theorem. By including the effects of a barred stellar distribution and figure rotation (81 \kms kpc $^{-1}$) and by assuming that the bar is oriented at $\theta$ $=$…
Recently, a new class of modified gravity theories formulated via an additional scalar and vector field on top of the standard tensor field has been proposed. The direct implications of these theories are expected to be relevant for…
The use of the tensor virial theorem (TVT) as a diagnostic of anisotropic velocity distributions in galaxies is revisited. The TVT provides a rigorous global link between velocity anisotropy, rotation and shape, but the quantities appearing…
We present a novel explanation of the well known $M_{\bullet}-\sigma$ relation. In a triaxial potential binaries with chaotic orbits within a sphere that encompass $\sim100$ times the mass of the super-massive black-hole (SMBH) have a…
The paper is studying the dynamics of twisted vortex bundles, which were detected in experimental investigations of superfluid turbulence in superfluid 3He-B. The analysis shows that a linear torsion oscillation of a vortex bundle is a…
We test the evolution of the correlation between black hole mass and bulge velocity dispersion (M$_{\rm BH}-\sigma$), using a carefully selected sample of 14 Seyfert 1 galaxies at $z=0.36\pm0.01$. We measure velocity dispersion from stellar…
Scalar Tensor Vector Gravity (STVG) is an alternative theory of gravitation that has successfully explained the rotation curves of nearby galaxies, the dynamics of galactic clusters, and cosmological data without dark matter, but has hardly…
An evolution of a spherical region, subjected to uniform buoyancy force, is investigated. Incompressibility and axial symmetry are assumed, together with a buoyancy discontinuity at the boundary. The boundary turns into a vortex sheet and…
This paper addresses the question of existence of (not necessarily self-similar) solutions to the 4-vortex problem that lead to total or partial collision. We begin by showing that energy considerations alone imply that, for the general…
A version of the virial theorem, which takes into account the effects of the non-compact extra-dimensions, is derived in the framework of the brane world models. In the braneworld scenario, the four dimensional effective Einstein equation…
This thesis details an effort to generate astrophysically interesting solutions to the two-body problem in General Relativity. The thesis consists of two main parts. The first part presents an analytical variational principle for describing…
The observed Tully-Fisher and Faber-Jackson laws between the baryonic mass of galaxies and the velocity of motion of stars at the edge of galaxies are explained within the framework of the model of accretion of galaxies around supermassive…