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A stable class of spacetimes with naked singularities

Marcus Kriele (1997)

Banach Center Publications

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

Ismaël Bailleul (2010)

Annales de l'I.H.P. Probabilités et statistiques

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 strong maximum principle for the Paneitz operator and a non-local flow for the Q -curvature

Matthew J. Gursky, Andrea Malchiodi (2015)

Journal of the European Mathematical Society

In this paper we consider Riemannian manifolds ( M n , g ) of dimension n 5 , with semi-positive Q -curvature and non-negative scalar curvature. Under these assumptions we prove (i) the Paneitz operator satisfies a strong maximum principle; (ii) the Paneitz operator is a positive operator; and (iii) its Green’s function is strictly positive. We then introduce a non-local flow whose stationary points are metrics of constant positive Q -curvature. Modifying the test function construction of Esposito-Robert, we show...

A survey of boundary value problems for bundles over complex spaces

Harris, Adam (2002)

Proceedings of the 21st Winter School "Geometry and Physics"

Let X be a reduced n -dimensional complex space, for which the set of singularities consists of finitely many points. If X ' X denotes the set of smooth points, the author considers a holomorphic vector bundle E X ' A , equipped with a Hermitian metric h , where A represents a closed analytic subset of complex codimension at least two. The results, surveyed in this paper, provide criteria for holomorphic extension of E across A , or across the singular points of X if A = . The approach taken here is via the metric...

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