arXiv research

The paper proves extremal black holes form at a critical point of gravitational collapse.

New method uses equivariant volume for gravitational extremization in holography.

Study on instability of extreme Reissner-Nordström spacetime perturbations.

Study on mode stability of gravitational instantons of type D.

New framework for gravitational perturbations of Kerr spacetimes, focusing on stability.

New solutions of gravity from branes wrapped on orbifolds.

Study proves curvature estimates for Kerr spacetime's linearized perturbations.

We prove boundedness and polynomial decay statements for solutions to the spin $\pm2$ generalized Teukolsky system on a Reissner-Nordström background with small charge. The first equation of the system is the generalization of the standard Teukolsky equation in Schwarzschild for the extreme component of the curvature $…

New magnetic memory effects found in gravitational waves and memory.

Neural networks improve gravitational-wave parameter estimation.

Formally constructs metrics near timelike geodesics in vacuum spacetimes.

Classifies gravitational instantons with quadratic volume growth.

The inequality $m^3\geq \frac{27π}{4} |\mathcal{J}_{2}||\mathcal{J}_{1}-\mathcal{J}_{2}|$ relating total mass and angular momenta, is established for (possibly dynamical) spacetimes admitting black holes of ring ($S^1\times S^2$) topology. This inequality is shown to be sharp in the sense that it is saturated precisely…

Survey of recent progress in gravitational instantons

Researchers create black holes isometric to extremal Reissner-Nordström.

In accessibility tests for digital preservation, over time we experience drifts of localized and labelled content in statistical models of evolving semantics represented as a vector field. This articulates the need to detect, measure, interpret and model outcomes of knowledge dynamics. To this end we employ a high-perf…

The paper proves unique characterization of gravitational instantons with specific volume growth.

Period maps surjective for certain gravitational instantons.

Authors prove Torelli theorem for a specific type of gravitational instantons.

This is our third paper in a series on the gravitational instantons. In this paper, we classify ALG and ALH gravitational instantons. In ALG case, we extend Hein's construction slightly and show that it's the only ALG gravitational instanton. In ALH case, we prove a Torelli-type theorem.

Gravitational instantons are non-Kähler, providing a counterexample to Euclidean Black Hole Uniqueness.

Existence proved for specific types of gravitational instantons.

This is our second paper in a series to study gravitational instantons, i.e. complete hyperkäler 4-manifolds with faster than quadratic curvature decay. We prove two main theorems: 1.The asymptotic rate of gravitational instantons to the standard models can be improved automatically. 2.Any ALF-D_k gravitational instant…

Proves infinitesimal rigidity of Hermitian gravitational instantons.

The holographic description in the presence of gravitational Chern-Simons term is studied. The modified gravitational equations are integrated by using the Fefferman-Graham expansion and the holographic stress-energy tensor is identified. The stress-energy tensor has both conformal anomaly and gravitational or, if re-f…

Study proves interaction of three impulsive gravitational waves, showing local solution and Lipschitz continuity.

New approach proves existence of gravitating vortices on Riemann surfaces.

Review of gravitational instantons in physics.

Gravitational instantons collapse to a punctured plane with a special Kahler metric.

The holographic duality can be extended to include quantum theories with broken coordinate invariance leading to the appearance of the gravitational anomalies. On the gravity side one adds the gravitational Chern-Simons term to the bulk action which gauge invariance is only up to the boundary terms. We analyze in detai…

Researchers embed gravitational instantons in higher-dimensional spaces.

Gravitational waves are predicted by the general theory of relativity. In [6] D. Christodoulou showed that gravitational waves have a nonlinear memory. We proved in [3] that the electromagnetic field contributes at highest order to the nonlinear memory effect of gravitational waves. In the present paper, we study this …

Charge measurements for instantons and gravitational perturbations.

In this paper we explicitly calculate the analogue of the 't Hooft SU(2) Yang--Mills instantons on Gibbons--Hawking multi-centered gravitational instantons which come in two parallel families: the multi-Eguchi--Hanson, or A_k ALE gravitational instantons and the multi-Taub--NUT, or A_k ALF gravitational instantons. We …

In general relativity, the local gravitational energy is best characterised by the quasilocal mass. The small sphere limit of quasilocal mass provides us the most local notion of gravitational energy. In four dimensions, the limits were shown be the stress tensor in non-vacuum and the Bel-Robinson tensor in vacuum. We …

Study of twistor spaces and minitwistor spaces for ALE gravitational instantons.

The paper studies gravitational instantons with flat limits and finds elliptic regularity estimates.

Study limits of quasi-local angular momentum at infinity of gravitating systems.

Researchers construct explicit bundles for ALF metrics, revealing rational patching matrices for gravitational instantons.

This paper is the sequel of our previous article "From ALE to ALF gravitational instantons", where we constructed ALF hyperkahler metrics on minimal resolutions of dihedral Kleinian singularities. In the present article we generalize the construction to smooth deformations of these Kleinian singularities, with help of …

The paper constructs gravitational instantons with unique collapse patterns.

Gravitational wave memory increases faster than Brownian motion in early universe and astrophysical sources.

Researchers solve field equations for special gravitational instantons.

Study toric gravitational instantons using rod structures and inequalities.

Simulation-based inference speeds up gravitational wave data analysis.

Penrose's conjecture links black holes and gravitational singularities.

New gravitational instantons and non-holomorphic minimal spheres discovered.

Solves time-optimal navigation on slippery slopes with cross gravitational wind.