Conveners
Exact Solutions in Four and Higher Dimensions: Block 1
- Fabio Briscese (SUSTech)
- Susan Scott (The Australian National University)
Description
This Parallel Session will be devoted to a variety of mathematical methods, associated mathematical structures and other mathematical aspects of the analysis of Einstein's field equations, constructing exact solutions and development of various solution generating techniques, interrelations of different approaches, classifications of solutions, studies of the structures and geometrical properties of particular solutions and classes of solutions in General Relativity as well as in various gravity, string gravity and supergravity models in four and higher dimensions.
In the so-called Ricci-based Gravity theories (RBGs for short) it is possible to transform a modified gravity problem into a standard problem in GR coupled to a modified matter source. Taking advantage of this property, one can also take non-vacuum solutions of GR and use them as seeds to generate new solutions in other theories of the RBG family. I will present recent results in this...
Based on our recent results we present the complete class of vacuum solutions in the Einstein–Gauss–Bonnet gravity which admit non-expanding, shear-free and twist-free null geodesic congruence and thus form the Kundt family of geometries. We explicitly derive the field equations and classify their solutions into three distinct subfamilies. Algebraic structure of the curvature tensors is...
In this talk, we discuss the extended gravitational decoupling approach for a static sphere in the framework of f(R,T) gravity where R represents the Ricci scalar and T is the trace of the energy-momentum tensor. In this approach, the domain of a known solution is extended by incorporating a new gravitational source. Transformations in radial and temporal metric functions split the system of...
In most cases the TOV equation appears as the relativistic counterpart of the classical condition for hydrostatic equilibrium, and characterises the static equilibrium of bound, spherical distributions of matter such as stars. In the present work we aim at showing that a generalised TOV equation also characterises the equilibrium of models endowed with other symmetries besides spherical. We...
The spacetimes with the NUT parameter are commonly associated with an unwanted defect in the form of a singular axis of symmetry. In the case of the Taub-NUT spacetime the most common remedy is the Misner’s interpretation: by compactifying the orbits of the cyclic time symmetry one discovers that the spacetime has a structure of the Hopf fibration. Then Taub-NUT may be regarded as a smooth...
In my talk, I will critically examine the Penrose conjecture according to which the gravitational entropy should be quantified via the Weyl curvature, with the Clifton-Ellis-Tavakol entropy being one specific realization of this proposal. In fact, I will show that in some exact inhomogeneous and anisotropic cosmological models which arise in general relativity with either closed and open...
