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48 results for vacuum extensions

Existence proved for static vacuum extensions near Schwarzschild spheres.

problem Proving existence of static vacuum extensions near Schwarzschild spheres.
method Existence and local uniqueness of static vacuum extensions for Bartnik data on a sphere near a Schwarzschild sphere.
result Existence of static vacuum extensions near Schwarzschild spheres.

Extends static vacuum metrics with specific boundary conditions.

problem Proving the existence of static vacuum metrics with prescribed boundary data.
method Introducing static regular types (I) and (II), showing local well-posedness, and confirming Bartnik's conjecture.
result Confirms Bartnik's static vacuum extension conjecture for a broad range of boundary conditions.

New static vacuum metrics confirmed for near Euclidean boundary data.

problem Establishing sufficient conditions for near Euclidean boundary data in static vacuum metrics.
method Using new arguments from studying the conjecture for arbitrary static vacuum metrics.
result Any hypersurface in a dense subfamily is static regular.

We establish a moduli space E\mathbb E of stationary vacuum metrics in a spacetime, and set up a well-defined boundary map ΠΠ in E\mathbb E, assigning a metric class with its Bartnik boundary data. Furthermore, we prove the boundary map ΠΠ is Fredholm by showing that the stationary vacuum equations (combined with p…

2018-07-01abs ↗pdf ↗

The paper extends Hawking--Page solutions to various spacetimes with singularities.

problem Understanding the extensions of Hawking--Page solutions with different types of singularities.
method Kaluza--Klein reduction and Christodoulou's methods.
result Extensions of Lorentzian Hawking--Page solutions with null, spacelike singularities, and Cauchy horizons of Taub--NUT type are proven.

Given a Riemannian 3-ball (Bˉ,g)(\bar B, g) of non-negative scalar curvature, Bartnik conjectured that (Bˉ,g)(\bar B, g) admits an asymptotically flat (AF) extension (without horizons) of the least possible ADM mass, and that such a mass-minimizer is an AF solution to the static vacuum Einstein equations, uniquely determined b…

2016-11-26abs ↗pdf ↗

We analyze the horizon and geodesic structure of a class of 4D off--diagonal metrics with deformed spherical symmetries, which are exact solutions of the vacuum Einstein equations with anholonomic variables. The maximal analytic extension of the ellipsoid type metrics are constructed and the Penrose diagrams are analyz…

2002-06-05abs ↗pdf ↗

We study the geometry of determinant line bundles associated to Dirac operators on compact odd dimensional manifolds. Physically, these arise as (local) vacuum line bundles in quantum gauge theory. We give a simplified derivation of the commutator anomaly formula using a construction based on noncyclic trace extensions…

2002-05-14abs ↗pdf ↗

We solve Bartnik's stationary extension problem near Schwarzschild spheres.

problem Existence and uniqueness of asymptotically flat stationary vacuum spacetimes.
method Developed a double geodesic gauge, reducing equations to elliptic and transport-type problems.
result Local well-posedness for Bartnik stationary metric extension problem near Schwarzschild spheres.

Paper studies Einstein vacuum equations with low regularity data.

problem Einstein vacuum equations with low regularity initial data.
method Combines Klainerman-Szeftel-Rodnianski curvature theorem, Czimek's extension procedure, and global elliptic estimates.
result Time of existence controlled by low regularity bounds on curvature in L2L^2.

A complete characterization is obtained of the asymptotic behavior of solutions of the static vacuum Einstein equations which have a (pseudo)-compact horizon or boundary and are complete away from the boundary. It is proved that the time-symmetric space-like hypersurface has only finitely many ends, each of which is ei…

2000-01-07abs ↗pdf ↗

The paper classifies vacuum static spaces with harmonic curvature.

problem Classifying vacuum static spaces with harmonic curvature.
method Extending the 4-dimensional work by Kim-Shin, the paper classifies nn-dimensional spaces (n5n\geq 5).
result New counterexamples to the Fischer-Marsden conjecture on compact vacuum static spaces.

Classifies patterns of symmetry breaking and vacuum degeneracy in scalar and gauge fields.

problem Understanding patterns of symmetry breaking and vacuum degeneracy in complex field systems.
method Uses mathematical classification of singular foliations to encode and classify patterns of spontaneous symmetry breaking and vacuum degeneracy.
result Mathematical classification provides a qualitative understanding of possible patterns of vacuum degeneracy.

We develop a general method of proving the ellipticity of boundary value problems for the stationary vacuum space time, by showing that the stationary vacuum field equations are elliptic subjected to a geometrically natural collection of boundary conditions in the projection formalism. Using this we prove the manifold …

2018-02-12abs ↗pdf ↗

Match van Stockum dust to vacuum metrics with a single parameter.

problem Matching van Stockum dust to vacuum metrics.
method 1-parametric family of non-static Papapetrou vacuum metrics, Ehlers and Kramer--Neugebauer transformations.
result Explicit examples of matching, including Bonnor metric and Lanczos--van Stockum dust metric.

The study finds compact vacuum static spaces with positive isotropic curvature are spheres or products of a circle and sphere.

problem Characterizing compact vacuum static spaces with positive isotropic curvature.
method Proving isometric equivalence to spheres or product spaces.
result Compact vacuum static spaces with positive isotropic curvature are isometric to spheres or product spaces.

Solves initial boundary value problem for vacuum Einstein equations and proves geometric uniqueness.

problem Initial boundary value problem for vacuum Einstein equations.
method Formulated IBVP, solved simultaneously in local harmonic coordinates, constructed unique maximal globally hyperbolic solution.
result Vacuum spacetimes satisfying fixed initial-boundary conditions and corner conditions are geometrically unique near the initial surface.

Researchers create solutions for naked singularities in Einstein vacuum equations.

problem Constructing solutions for the interior region of naked singularities in Einstein vacuum equations.
method Novel self-similarity and study of mixed degenerate elliptic-hyperbolic PDE's.
result Gluing together interior and exterior solutions produces a naked singularity.

Constructed static vacuum metrics in 5D with negative cosmological constant.

problem Finding static vacuum solutions in 5D with negative cosmological constant.
method Numerically constructed two families of metrics with squashed conformal infinity.
result Constructed metrics with squashed conformal infinity conformal to any squashed 3D sphere.

The study classifies spaces with specific conformal vector fields.

problem Characterizing closed vacuum static spaces with non-Killing conformal vector fields.
method Provided characterizations and established an identity involving the characteristic function.
result Derived a rigidity theorem and classified spaces with the vector field.

Extends Killing vector fields to beyond compact Cauchy horizons.

problem Proves existence of Killing vector fields beyond compact Cauchy horizons.
method New unique continuation theorem for wave equations through smooth compact lightlike hypersurfaces; novel Carleman type estimate.
result Killing vector field exists on both sides of the horizon.

Study geometric properties of generalized vacuum static spaces.

problem Estimating geometric properties of generalized φ\varphi-vacuum static spaces.
method Proving estimates for φ\varphi-scalar curvature and first eigenvalue of the Jacobi operator, and rigidity under various geometric assumptions.
result Proved a result related to the Cosmic no-hair conjecture.

The paper confirms the existence of 5D regular static vacuum solutions with multiple black holes and Kasner asymptotics.

problem Existence of 5D regular static vacuum solutions with multiple black holes.
method Construction of specific examples with different horizon topologies and analysis of spacetime properties.
result Existence of 5D vacuum solitons with Kasner asymptotics and regular static space-periodic spacetimes.

This paper completes the classification of S1-symmetric static vacuum black holes.

problem Identifying all S1-symmetric static vacuum black hole solutions.
method Analyzing and constructing known solutions and proving their completeness.
result Proves that the Schwarzschild, Boost, and Weyl-Korotkin-Nicolai families exhaust all S1-symmetric static vacuum black hole solutions.

In a recent paper, the authors established the uniqueness of photon spheres in static vacuum asymptotically flat spacetimes by adapting Bunting and Masood-ul-Alam's proof of static vacuum black hole uniqueness. Here, we establish uniqueness of suitably defined sub-extremal photon spheres in static electro-vacuum asympt…

2015-08-03abs ↗pdf ↗

New exact spherically symmetric vacuum solutions found in Finsler gravity.

problem Finding exact vacuum solutions in Finsler gravity.
method Spherically symmetric, asymptotically flat Berwald spacetimes solved for Finsler gravity vacuum equation.
result Only one class of spherically symmetric Berwald spacetimes is compatible with asymptotic flatness and a well-defined causal structure.

The paper examines the initial geometry of vacuum cosmological spacetimes and introduces new methods to characterize their behavior.

problem Characterizing the initial geometry of vacuum cosmological spacetimes.
method Analyzes Gowdy and non-Gowdy spacetimes with TNT^N-actions, introduces a monotonic quantity for Kasner spacetimes, and uses curvature and volume bounds.
result Evidence of AVTD behavior in Gowdy spacetimes and sufficient conditions for nonGowdy spacetimes.

We prove that there are no restrictions on the spatial topology of asymptotically flat solutions of the vacuum Einstein equations in (n+1)-dimensions. We do this by gluing a solution of the vacuum constraint equations on an arbitrary compact manifold to an asymptotically Euclidean solution of the constraints on R^n. Fo…

2002-06-12abs ↗pdf ↗

It is proved that the only geodesically complete stationary vacuum solution of the Einstein equations is the empty Minkowski space, or a quotient of it by a discrete group of isometries, generalizing a classical result of Lichnerowicz. In addition, we obtain an apriori bound on the curvature of stationary vacuum soluti…

2000-01-27abs ↗pdf ↗