Related papers: The theorem that was none - I. Early history
Normally the issue or question of the time of arrival of light rays at an observer coming from a given source is associated with Fermat's Principle of Least Time which yields paths of extremal time. We here investigate a related but…
There exists a growing body of observational evidence supporting a non-vanishing cosmological constant at the present epoch. We examine the possibility that such a term may arise directly from the potential energy which drove an…
Some of the theoretical challenges posed by the general relativistic description of binary systems of compact objects (neutron stars or black holes) are reviewed. We recall the various ways one can use the theory of the motion, and of the…
A simple and {\it innocent} modification of Poisson's equation leads to a modified Newtonnian theory of gravitation where a localized and {\it positive} energy density of the gravitational field contributes to its own source. The result is…
We contrast the evolution of gravitational binary mergers for the two cases of a black hole and a normal neutron star, and a black hole and a self-bound strange quark matter star. In both cases inspiral continues until the Roche limit is…
An earlier forward and backward in time formalism developed by us to discuss non-relativistic electron diffraction is generalized to the relativistic case and here applied to photons. We show how naturally the zero-point energy emerges in…
An active stage of relativistic astrophysics started in 1963 since in this year, quasars were discovered, Kerr solution has been found and the first Texas Symposium on Relativistic Astrophysics was organized in Dallas. Five years later, in…
Euler's equations of motion are derived exactly for a rigid, triaxial, internally frictionless neutron star spinning down electromagnetically in vacuo. It is shown that the star precesses, but not freely: its regular precession relative to…
The existence of light (a massless U(1) gauge boson) is one of unresolved mysteries in nature. In this paper, we would like to propose that light is originated from certain quantum orders in our vacuum. We will construct quantum models on…
It is shown that a first-order relativistic perturbation theory for the open, flat or closed Friedmann-Lemaitre-Robertson-Walker universe admits one, and only one, gauge-invariant quantity which describes the perturbation to the energy…
I summarize the status of pulsar theory, now 35 years after their discovery. Although progress has been made in understanding the relevant processes involved, there are several widely held misconceptions that are inhibiting further…
On the basis of hypotheses, that a density of weakly interacting particles in the Universe has an order of nuclear matter density or more the Lagrangian is offered, through which one can be obtained a propagator of a vector boson with a…
Inserting a varying Lambda in Einstein's field equations can be made consistent with the Bianchi identities by allowing for torsion, without the need to add scalar field degrees of freedom. In the minimal such theory, Lambda is totally free…
In a gravitational theory with a massless photon the maximum charge-to-mass ratio of black holes approaches the prediction of the Einstein-Maxwell theory as black hole mass increases: $Q_{\rm ext}/M =1+ \alpha/M^2$ for some constant…
In this research-paper, many of the general-relativity-tests such as bending of light near a star and gravitational red/blue shift are explained without general-relativity & even without Newtonian-approach. The authors first raise questions…
An outstanding problem in gravitation theory and relativistic astrophysics today is to understand the final outcome of an endless gravitational collapse. Such a continual collapse would take place when stars more massive than few times the…
The process that leads to the formation and early evolution of low-mass stars is in a broad sense well understood theoretically and carefully traced observationally. The largest uncertainties in this framework reside in the poorly known…
We review recent theoretical results on the formation of the first stars and quasars in the universe, and emphasize related open questions. In particular, we list important differences between the star formation process at high redshifts…
After a brief introduction to gravitational lensing theory, a rough overview of the types of gravitational lensing statistics that have been performed so far will be given. I shall then concentrate on recent results of galaxy-galaxy…
Among the remarkable strides made by JWST is the discovery of the earliest star clusters found to date. These have been proposed as early progenitors of globular clusters, which are known to come from the early stages of star formation in…