A note on distributional semi-Riemannian geometry.
A note on noncommutative and false noncommutative spaces.
A note on proper conformal vector fields in Bianchi type I space-times.
A principle involving the variation of the metric tensor in a stationary space-time of general relativity
A propos de la conjecture de la balle liquide en relativité générale
A review of procedures for summing Kapteyn series in mathematical physics.
A scalar geodesic deviation equation and a phase theorem.
A singular lagrangian model for N-body relativistic interactions
A space-time theorem in the de Sitter-world. (Ein Raum-Zeit-Satz für die de Sitter-Welt.)
A speculative approach to quantum gravity.
A stable class of spacetimes with naked singularities
We present a stable class of spacetimes which satisfy the conditions of the singularity theorem of Hawking & Penrose (1970), and which contain naked singularities. This offers counterexamples to a geometric version of the strong cosmic censorship hypothesis.
A stochastic approach to relativistic diffusions
A new class of relativistic diffusions encompassing all the previously studied examples has recently been introduced in the article of C. Chevalier and F. Debbasch (J. Math. Phys. 49 (2008) 043303), both in a heuristic and analytic way. A stochastic approach of these processes is proposed here, in the general framework of lorentzian geometry. In considering the dynamics of the random motion in strongly causal spacetimes, we are able to give a simple definition of the one-particle distribution function...
A unified model of phantom energy and dark matter.
A xylophone detector in space
We discuss spacecraft Doppler tracking for detecting gravitational waves in which Doppler data recorded on the ground are linearly combined with Doppler measurements made on board a spacecraft. By using the four-link radio system first proposed by Vessot and Levine [1] we derive a new method for removing from the combined data the frequency fluctuations due to the Earth troposphere, ionosphere, and mechanical vibrations of the antenna on the ground. This method also reduces the frequency fluctuations...
Accelerated Lyra's cosmology driven by electromagnetic field in inhomogeneous universe.
Algebro-geometric approach to the Ernst equation I. Mathematical Preliminaries
1. Introduction. It is well known that methods of algebraic geometry and, in particular, Riemann surface techniques are well suited for the solution of nonlinear integrable equations. For instance, for nonlinear evolution equations, so called 'finite gap' solutions have been found by the help of these methods. In 1989 Korotkin [9] succeeded in applying these techniques to the Ernst equation, which is equivalent to Einstein's vacuum equation for axisymmetric stationary fields. But, the Ernst equation...
An almost-Robertson-Walker universe model and the equivalence classes of perturbations : nonbarotropic perfect fluids
An application of the special Reissner-Nordström space-time to description of the universe in the neighbourhood of the Planck era
The description of the special Reissner-Nordström space-time in the Planck era is presented and its comparison with the Robertson-Walker space-time is given.
An explicit determination of the non-self-adjoint wave equations on curved space-time that satisfy Huygens' principle. Part I : Petrov type N background space-times
An explicit determination of the Petrov type D spacetimes on which Weyl's neutrino equation and Maxwell's equations satisfy Huygens' principle