Related papers: Cosmology, Oscillating Physics and Oscilllating Bi…
Using the idea of regularisation of singularities due to the variability of the fundamental constants in cosmology we study the cyclic universe models. We find two models of oscillating and non-singular mass density and pressure…
Axisymmetric disks of eccentric Kepler orbits are vulnerable to an instability which causes orbits to exponentially grow in inclination, decrease in eccentricity, and cluster in their angle of pericenter. Geometrically, the disk expands to…
We study the expansion of the universe at late times in the case that the cosmological constant obeys certain scaling laws motivated by renormalisation group running in quantum theories. The renormalisation scale is identified with the…
We consider the evolution by crystalline curvature of a planar set in a stratified medium, modeled by a periodic forcing term. We characterize the limit evolution law as the period of the oscillations tends to zero. Even if the model is…
This paper describes how the non-gravitational contribution to Galactic Velocity Rotation Curves can be explained in terms of a negative Cosmological Constant ($\Lambda$). It will be shown that the Cosmological Constant leads to a velocity…
In polar oscillations of compact stars dynamical changes in spacetime and matter are in general coupled together. Based on the theory of stellar pulsation proposed by Allen et al. [Phys. Rev. D 58, 124012 (1998)], we establish a feasible…
Measurements of the peculiar velocities of large samples of galaxies enable new tests of the standard cosmological model, including determination of the growth rate of cosmic structure that encodes gravitational physics. With the size of…
The planetary obliquity plays a significant role in determining physical properties of planetary surfaces and climate. As direct detection is constrained due to the present observation accuracy, kinetic theories are helpful to predict the…
In this note we consider a variable $G$ cosmology which is consistent with observation and which had successfully predicted an ever expanding accelerating universe. It is shown that the observed shortening of the orbital periods of binary…
We propose to employ the circular polarization of gravitational waves emitted by core-collapse supernovae as an unequivocal indication of rapid rotation deep in their cores. It has been demonstrated by three dimensional simulations that…
A continuous system such as a galactic disc is shown to be well approximated by an N-ring differentially rotating self-gravitating system. Lowest order (m=1) non-axisymmetric features such as lopsidedness and warps are global in nature and…
Using the precise times of mid-egress of the eclipsing polar HU Aqr, we discovered that this polar is orbited by two or more giant planets. The two planets detected so far have masses of at least 5.9 and 4.5\,M_{Jup}. Their respective…
In standard cosmology, the late Universe is assumed to be statistically homogeneous and isotropic. However, a recent study based on galaxy clusters by Migkas et al. (2021, arXiv:2103.13904) found an apparent spatial variation of…
Quasinormal modes of ultra compact stars with uniform energy density have been calculated. For less compact stars, there is only one very slowly damped polar mode (corresponding to the Kelvin f-mode) for each spherical harmonic index $l$.…
Positive and negative pulsar breaking indices suggest that some fraction of the pulsar spindown torque undergoes a cyclic evolution. The observed strong correlation of `anomalous' breaking indices with pulsar age implies that the…
We present an analysis of structural features of all known galaxies with optical polar rings. We find a clear dichotomy for objects of this peculiar class. Bulge-dominated S0 galaxies possess only short narrow rings, while disk-dominated…
We derive the perturbation equations for relativistic stars in scalar-tensor theories of gravity and study the corresponding oscillation spectrum. We show that the frequency of the emitted gravitational waves is shifted proportionally to…
I critically discuss in a pedagogical and phenomenological way a few crucial tests challenging the claims by Pietronero and collaborators that there is no evidence from available galaxy catalogues that the Universe is actually homogeneous…
In this paper it is shown that dynamics based on a variation of the gravitational constant $G$ with time solves several puzzling and anomalous features observed, for example the rotation curves of galaxies (attributed to as yet undetected…
We have derived the relationship between polarization and intensity fluctuations due to point sources. In the case of a Poisson distribution of a population with uniform evolution properties and constant polarization degree, polarization…