Related papers: General relativistic density perturbations
We study the dynamical effect of relative velocities between dark matter and baryonic fluids, which remained supersonic after the epoch of recombination. The impact of this supersonic motion on the formation of cosmological structures was…
Long-wavelength matter inhomogeneities contain cleaner information on the nature of primordial perturbations as well as the physics of the early universe. The large-scale coherent overdensity and tidal force, not directly observable for a…
In this work, one examines how the presence of a non-minimal coupling between the spacetime curvature and matter affects the evolution of cosmological perturbations around a homogeneous and isotropic Universe and hence the formation of…
Tilted two fluids cosmological models with variable G and {\Lambda} In General Relativity are presented. Here one fluid is matter field modelling material content of the universe and another fluid is radiation field modelling the cosmic…
Modified gravity theories with a nonminimal coupling between curvature and matter offer a compelling alternative to dark energy and dark matter by introducing an explicit interaction between matter and curvature invariants. Two of the main…
We investigate decoherence of quantum superpositions induced by gravitational time dilation and spontaneous emission between two atomic levels. It has been shown that gravitational time dilation can be an universal decoherence source. Here,…
If the Universe's energy density was dominated by a fast-rolling scalar field while the radiation bath was hot enough to thermally produce dark matter, then dark matter with larger-than-canonical annihilation cross sections can generate the…
Global topological defects produce nonzero stress-energy throughout spacetime, and as a result can have observable gravitational influence on surrounding matter. Gravitational effects of global strings are used to place bounds on their…
Supersymmetry predicts multiple flat directions, some of which carry a net baryon or lepton number. Condensates in such directions form during inflation and later fragment into Q-balls, which can become the building blocks of primordial…
Motivated by their potential role as dark matter, we study the cosmological evolution of light scalar and vector fields non-minimally coupled to gravity. Our focus is on a situation where the dominant contribution to the energy density…
Continued star formation over the lifetime of a galaxy suggests that low metalicity gas is steadily flowing in from the circumgalactic medium. Also, cosmological simulations of large-scale structure formation imply that gas is accreted onto…
We propose a simple scenario which explains the observed matter-antimatter imbalance and the origin of dark matter in the Universe. We use the Einstein-Cartan-Sciama-Kibble theory of gravity which naturally extends general relativity to…
Recent work has demonstrated that exoplanetary system properties correlate strongly with ambient stellar clustering in six-dimensional stellar position-velocity phase space, quantified by dividing planetary systems into sub-samples with…
Quantum gravity may shed light on the prehistory of the universe. Quantum corrections to gravity affect the dynamics of the expansion of the universe. Their influence is studied on the example of the exactly solvable quantum model. The…
Detached circumplanetary disks are unstable to tilting as a result of the stellar tidal potential. We examine how a tilted circumplanetary disk affects the evolution of the spin axis of an oblate planet. The disk is evolved using…
Gravitational-collapse-based explanations of the cosmic web lead to problems in estimating the total mass in the universe. A first-principles several-scales model is developed here for the structural organisation of cosmic matter in a flat…
If general relativity (GR) describes the expansion of the Universe, the observed cosmic acceleration implies the existence of a `dark energy'. However, while the Universe is on average homogeneous on large scales, it is inhomogeneous on…
This is a review of recent progress concerning generic spacelike singularities in general relativity. For brevity the main focus is on singularities in vacuum spacetimes, although the connection with, and the role of, matter for generic…
The importance of angular momentum in regulating the sizes of galactic disks and by this their star formation history is highlighted. Tidal torques and accretion of satellites in principle provide enough angular momentum to form disks with…
General relativistic corrections to the expansion rate of the Universe arise when the Einstein equations are averaged over a spatial volume in a locally inhomogeneous cosmology. It has been suggested that they may contribute to the observed…