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R. R. Volotskova

Publications and source records attributed to R. R. Volotskova.

2 recordsLinked to original sources

Testing generalized spacetimes for black holes using the Hod function representation of the hoop conjecture

The hoop conjecture, due to Thorne, is a fundamental aspect of black holes in classical general relativity. Recently, generalized classes of regular spherically symmetric static black holes with arbitrary exponents coupled to nonlinear electrodynamics have been constructed in the literature. The conjecture in those spacetimes could be violated if only the asymptotic mass $M_{\infty}$ is used. To avoid such violations, Hod earlier suggested the appropriate mass function and stated the conjecture in terms of what we call the Hod function. The conjecture can then be applied to any given static spacetime to test whether or not it represents black holes. It is shown here that the conjecture is protected in the above constructed class of generalized spacetimes thus supporting them as black holes. However, it is argued that there are factors, including violation of the conjecture, that militate against the proposed \textit{new} class of solutions to be qualifying as black holes. Finally, we exemplify that the Hod mass $M(r\leq R)$ in the conjecture is exactly the \textit{matter} counterpart of the Misner-Sharp \textit{geometrical} quasilocal mass $m(r\leq R)$ of general relativity. Thus any conclusion based on Hod function is strictly a conclusion of general relativity.

gr-qc

On the Hoop conjecture in Einstein gravity coupled to nonlinear electrodynamics

The famous hoop conjecture by Thorne has been claimed to be\ violated in curved spacetimes coupled to linear electrodynamics. Hod \cite{Hod:2018} has recently refuted this claim by clarifying the status and validity of the conjecture appropriately interpreting the gravitational mass parameter $M$. However, it turns out that partial violations of the conjecture might seemingly occur also in the well known regular curved spacetimes of gravity coupled to \textit{nonlinear electrodynamic}s. Using the interpretation of $M$ in a generic form accommodating nonlinear electrodynamic coupling, we illustrate a novel extension that the hoop conjecture is \textit{not} violated even in such curved spacetimes. We introduce a Hod function summarizing the hoop conjecture and find that it surprisingly encapsulates the transition regimes between "horizon and no horizon" across the critical values determined essentially by the concerned curved geometries.

gr-qc