arXiv research

The study proves local rigidity of minimal 2-spheres in electrovacuum spacetimes.

We revisit the problem of extension of a Killing vector field in a spacetime which is solution to the Einstein-Maxwell equation. This extension has been proved to be unique in the case of a Killing vector field which is normal to a bifurcate horizon by Yu. Here we generalize the extension of the vector field to a stron…

We show a uniqueness result for the n-dimensional spatial Reissner-Nordström manifold: a static, electrovacuum, asymptotically flat system which is asymptotically Reissner-Nordström is a subextremal Reissner-Nordström manifold with positive mass, provided that its inner boundary is a (possibly disconnected) photon sphe…

The paper classifies electrovacuum spaces in higher dimensions, proving several key results.

Completed classification of Einstein spaces with specific metric properties.

This paper explores charged black holes in 3+1 dimensions, finding limitations on their existence.

We note an area-charge inequality orignially due to Gibbons: if the outermost horizon $S$ in an asymptotically flat electrovacuum initial data set is connected then $|q|\leq r$, where $q$ is the total charge and $r=\sqrt{A/4π}$ is the area radius of $S$. A consequence of this inequality is that for connected black hole…

New solution to Einstein-Maxwell equations invariant under dilations.

The paper finds conditions for pseudosymmetric spacetimes to be perfect fluids.

We consider (flat) Cauchy-complete GH spacetimes, i.e., globally hyperbolic flat lorentzian manifolds admitting some Cauchy hypersurface on which the ambient lorentzian metric restricts as a complete riemannian metric. We define a family of such spacetimes - model spacetimes - including four subfamilies: translation sp…

Jebsen-Birkhoff theorem extended to Berwald spacetimes.

The paper introduces and analyzes pseudo generalized Ricci-recurrent spacetimes in modified gravity.

The study characterizes spacetimes with quasi-constant sectional curvature and explores their properties in $\mathcal{F}(\mathcal{R})$-gravity.

The article introduces pseudo generalized Ricci-recurrent spacetimes and their applications in modified gravity.

The paper studies the past inextendibility of FLRW spacetimes using the VDR asymptote.

Study explores geometric properties of Vaidya-Bonner-de Sitter spacetime.

The study characterizes GRW spacetimes with gradient solitons and phantom era.

Characterizes Lorentzian manifolds embeddable in Minkowski spacetime.

New proof shows FLRW spacetimes can't be extended smoothly in certain axisymmetric cases.

Study of quasilocal mass using isometric embedding in various spacetimes.

Characterizes pseudo B-symmetric spacetimes and their implications in f(R) gravity.

Characterizes a specific type of spacetime using vector fields.

Study maximal hypersurfaces in open spacetimes using a maximum principle.

The study explores properties of a specific type of spacetime.

New findings show cosmological constant as initial condition for non-isotropic spacetimes.

We consider the class of locally boost isotropic spacetimes in arbitrary dimension. For any spacetime with boost isotropy, the corresponding curvature tensor and all of its covariant derivatives must be simultaneously of alignment type ${\bf D}$ relative to some common null frame. Such spacetimes are known as type ${\b…

Study finds unique and non-existent constant mean curvature hypersurfaces in specific spacetimes.

New Galilean spacetimes found as pp-wave reductions.

Study revisits Bondi mass and discusses memory effect in polyhomogeneous spacetimes.

Study baryogenesis in conformally flat spacetimes using causal fermion systems.

In 2+1 dimensions, all complete spacetimes are cylindrical.

The study examines perfect fluid spacetimes and their properties.

Causal spacetimes with Ricci tensor have unique transformations.

Milne-like spacetimes are a class of FLRW models which admit $C^0$ spacetime extensions through the big bang. The boundary of a Milne-like spacetime can be identified with a null cone in the extension. We find that the comoving observers all emanate from a single point in the extension. This suggests that something phy…

Detect spacetime curvature with event causality measurements.

The Levi-Civita connection and geodesic equations for a stationary spacetime are studied in depth. General formulae which generalize those for warped products are obtained. These results are applicated to some regions of Kerr spacetime previously studied by using variational methods. We show that they are neither space…

This study proves energy bounds in specific AdS spacetimes.

We formulate the concept of time machine structure for spacetimes exhibiting a compactely constructed region with closed timelike curves. After reviewing essential properties of the pseudo Schwarzschild spacetime introduced by A. Ori, we present an analysis of its geodesics analogous to the one conducted in the case of…

Researchers found differential invariants for Kundt spacetimes.

Classifies Lie algebras and related spacetimes for a specific type of symmetry.

No closed timelike geodesics in Kerr spacetimes, proving absence of closed causal geodesics.

Detect spacetime curvature without rulers and clocks in 3D.

Characterizes spacetimes using doubly torqued vectors.

A generalized Robertson-Walker spacetime is the warped product with base an open interval of the real line endowed with the opposite of its metric and base any Riemannian manifold. The family of generalized Robertson-Walker spacetimes widely extends the one of classical Robertson-Walker spacetimes. In this article we p…

Study harmonicity of metrics in generalized Kantowski-Sachs spacetime.

The study examines Ricci solitons and curvature inheritance on Robinson-Trautman spacetimes.

The higher-dimensional Kerr-NUT-de Sitter spacetime describes the general rotating asymptotically de Sitter black hole with NUT parameters. It is known that such a spacetime possesses a rank-2 closed conformal Killing-Yano (CKY) tensor as a ``hidden'' symmetry which provides the separation of variables for the geodesic…

In this paper, under natural geometric and physical assumptions we provide new uniqueness and non-existence results for complete maximal hypersurfaces in spatially open Robertson-Walker spacetimes whose fiber is flat. Moreover, our results are applied to relevant spacetimes as the steady state spacetime, Einstein-de Si…