X iv : g r - qc / 9 90 60 44 v 1 1 4 Ju n 19 99 Trieste - DSM - QM 450 May 1999 Eigenvalues as Dynamical Variables 1 Giovanni Landi

ar X iv : g r - qc / 9 90 61 19 v 1 2 9 Ju n 19 99 Gravitational memory of natural wormholes

A traversable wormhole solution of general scalar–tensor field equations is presented. We have shown, after a numerical analysis for the behavior of the scalar field of Brans-Dicke theory, that the solution is completely singularity– free. Furthermore, the analysis of more general scalar field dependent coupling constants indicates that the gravitational memory phenomenon may play an important ...

ar X iv : g r - qc / 9 70 80 41 v 2 1 2 Fe b 19 98 Gravity from Dirac Eigenvalues ∗

We study a formulation of euclidean general relativity in which the dynamical variables are given by a sequence of real numbers λn, representing the eigenvalues of the Dirac operator on the curved spacetime. These quantities are diffeomorphisminvariant functions of the metric and they form an infinite set of “physical observables” for general relativity. Recent work of Connes and Chamseddine su...

ar X iv : g r - qc / 9 80 70 11 v 1 6 J ul 1 99 8 Constraints on spacetime manifold in Euclidean supergravity in terms of Dirac eigenvalues

We generalize previous work on Dirac eigenvalues as dynamical variables of Euclidean supergravity. The most general set of constraints on the curvatures of the tangent bundle and on the spinor bundle of the spacetime manifold, under which spacetime addmits Dirac eigenvalues as observables, are derived. Typeset using REVTEX

ar X iv : n uc l - th / 9 90 60 29 v 3 1 5 Ju l 1 99 9 1 Quark Matter ’ 99 — Theoretical Summary : What Next ?

ar X iv : g r - qc / 9 90 70 47 v 1 1 3 Ju l 1 99 9 Dynamics of Bianchi IX universe with massive scalar field

The dynamics of the Bianchi IX cosmological model with minimally coupled massive real scalar field is studied. The possibility of non-singular transition from contraction to expansion is shown. A set of initial conditions that lead to non-singular solutions is studied numerically.