The theory of gravitational lensing is reviewed from a spacetime perspective, without quasi-
Newtonian approximations. More precisely, the review covers all aspects of gravitational …

In this paper, we investigate Pseudo-Z symmetric space-time manifolds. First, we deal with
elementary properties showing that the associated form A k is closed: in the case the Ricci …

This is intended as an introduction to and review of the work of V, Arnold and his
collaborators on the theory of Lagrangian and Legendrian submanifolds and their …

Entanglement temperatures (ET) are a generalization of Unruh temperatures valid for states
reduced to any region of space. They encode in a thermal fashion the high-energy behavior …

We classify singularities of lightlike hypersurfaces in Minkowski 4-space via the contact
invariants for the corresponding spacelike surfaces and lightcones. 1. Introduction. The …

We explore the holographic principle in the context of asymptotically flat space-times by
means of the asymptotic symmetry group of this class of space-times, the so called Bondi …

We consider the singularities of lightlike hypersurfaces along spacelike submanifolds in
Lorentz–Minkowski space of general codimension. As an application of the theory of …

The null surface formulation of general relativity is developed for 2+ 1 dimensional gravity.
The geometrical meaning of the metricity condition is analyzed and two approaches to the …

The images of many distant galaxies are displaced, distorted and often multiplied by the
presence of foreground massive galaxies near the line of sight; the foreground galaxies act …

A study of the lightcone of the Gödel universe is extended to the so-called Gödel-like
spacetimes. This family of highly symmetric 4D Lorentzian spaces is defined by metrics of …