Description
chair: Mikołaj Korzyński, Patryk Mach
It is well known that the Einstein equations can be interpreted as a system of PDEs describing a geometric flow - a continuous family of Riemannian metrics on a given topological manifold.
In this perspective the global structure of solutions to the Einstein equations is analysed using this geometric flow to obtain information on the asymptotic behaviour towards future and past. In this talk...
In this talk, we investigate the gravitational collapse of the Oppenheimer-Snyder dust cloud with spatially constant matter density from a quasi-local perspective. Given a closed two-surface within the star, three versions of the quasi-local energy are discussed.
This talk is based on a recent paper with Xiaokai He [Class. Quantum Grav. 37(2020)185016, arXiv:2005.04659].
I will show how to generalize classical results on linear metric perturbations to any higher orders of perturbation expansion and discuss some possible applications.
During the talk the course and results of gravitational collapse within the Higgs-dark matter sector using the double null formalism will be presented. The employed model consists of two scalar fields non-minimally coupled to gravity, one of which is charged under a U(1) gauge field and represents a stable dark matter candidate. The uncharged scalar may represent a real part of the Higgs...
The problem of quasilocal mass has been extensively studied mainly in four dimensions. Here we report results regarding several quasilocal mass proposals in spacetime dimensions $n \geq 4$. After generalising three distinct quasilocal mass definitions to higher dimensions under appropriate assumptions, we evaluate their small sphere limits along lightcone cuts shrinking towards the lightcone...
The problem of integrals of the motion for the conformal Killing fields in curved space-times equipped with electromagnetic backgrounds will be analysed. In particular, for the pp-wave spacetimes the explicit form of conserved charges will be presented. Relations between these charges and symmetries will be discussed in various Lagrangian and Hamiltonian approaches.
Spacetimes with NUT parameter are known to posses a string-like conical singularity. We present a method for obtaining non-singular Kerr-NUT spacetimes with an arbitrary cosmological constant, via an analogue of the Misner interpretation of Taub-NUT spacetimes. Among the non-singular solution there is a class for which also one of the horizons is projectively non-singular, i.e. its space of...
The widely accepted ADM expression for the energy of an asymptotically flat spacetime satisfies a "natural" consistency test - its second variation is equal to the canonical hamiltonian functional for linearized gravity on a Minkowski background. A viable quasi-local mass candidate should posses a similar property, namely - its second-order approximation should equal the hamiltonian of the...
A family of global shock-wave solutions of the Einstein field equations for a perfect fluid are constructed. These shock-wave solutions consist of an interior self-similar expanding wave and an exterior self-similar static wave, separated by a spherical shock surface. The interior and exterior fluids are assumed to have isothermal equations of state of the form $p = \sigma\rho$ and $\bar{p} =...
I will present the ${\it No Hair}$ result for the solution of Einstein equations describing the non-vacuum regular interior and the vacuum exterior of a spinning black hole. There are only two parameters characterizing the vacuum exterior and two parameters for the non-vacuum regular interior of a spinning black hole.
These two sets of two parameters are connected by the matching condition...
