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Jean Baptiste Patenou

Publications and source records attributed to Jean Baptiste Patenou.

2 recordsLinked to original sources

Conformal Scale Geometry of Spacetime -- A lower bound for a total mass

We devise a new approach for the analysis of issues of geometric pathologies and black holes of a spacetime, based on a new mass function defined on an ideal un-physical spacetime which models time-flow or time dilation. The mass function is interpreted as an "extra" local energy density that encodes the rate at which time comes to a "stop" (hardly visible) or it measures how quickly the (illusory) Event horizon forms. This latter is defined on the manifold with corners resulting from an appropriate conformal compactification of the original physical space-time, the concrete choice of compactification being tied to the geometric structure of collapsing spacetimes. We define the (illusory) Event horizon as the set of zero-mass function and provide conditions for which it stands as a "black hole's event horizon". As a first main result owing to the new definitions here, we establish the existence of a lower bound for the "total mass", provided some conditions on the extrinsic curvature of the space-time are satisfied. The proof builds on geometric flow techniques. Namely, by flowing the "black hole's event horizon", one is able to derive via a Lagrangian formulation, a Minimization Problem for the "total mass" and which is addressed under Iso-perimetric constraints' perspective. Prior to this main result, we first provide hypotheses which assure the trapped surface's formation in this context.

math.AP↗

Cauchy problem on two characteristic hypersurfaces for the Einstein-Vlasov-Scalar field equations in temporal gauge

In this paper, we consider the initial value problem for the Einstein-Vlasov-Scalar field equations in temporal gauge, where the initial data are prescribed on two characteristic smooth intersecting hypersurfaces. From a suitable choice of some free data, the initial data constraints's problem is solved globally, then the evolution problem relative to the deduced initial data is solved locally in time.

math-ph↗