Doctoral defence: Konstantinos Pallikaris “Novel exact black holes in Einstein gravity”

On 5 June 2026 at 14, Konstantinos Pallikaris will defend his doctoral thesis "Novel exact black holes in Einstein gravity".

Supervisors:

Dr. Manuel Hohmann, Associate Professor in Theoretical Physics, Institute of Physics, University of Tartu

PhD Emmanuel Saridakis, Research director, IAASARS, National Observatory of Athens, Greece

Opponent:

PhD Roman Konoplya. Assistant professor, RCTPA, Institute of Physics, Silesian University in Opava, Czech Republic

Summary

Black holes are among the most extreme objects in the Universe, marking the point where our understanding of gravity is pushed to its limit. They are powerful theoretical laboratories for studying gravity, matter, and geometry. In this thesis, we construct new exact solutions of Einstein’s equations, focusing on how new matter models and solution-generating methods can lead to previously unknown spacetime geometries. The first part of the thesis considers Einstein gravity coupled to a generalization of Maxwell’s electromagnetism. It introduces a model of two interacting electromagnetic fields. When coupled to gravity, this model leads to new families of black holes with rich thermodynamics in different spacetime dimensions. In some cases, they describe regular black holes, namely compact objects with a horizon and a regular core. The second part of the thesis uses solution-generating methods to construct new spacetimes from known ones. One result is the electromagnetic swirling solution, which describes an inherently rotating background spacetime with an external electromagnetic field present. A black hole placed in this background is forced to co-rotate with it, while also interacting with the external field. Another result is the Kerr–Levi-Civita spacetime, a new exact rotating solution of the vacuum Einstein equations. Unlike the standard Kerr black hole, it inherits additional geometric structure from the Levi-Civita background and its rotating generalization. For suitable parameter ranges, it describes a regular black hole with a swirling type of rotation. Overall, the thesis demonstrates that the spectrum of exact black-hole solutions in Einstein’s theory of gravity is still largely unexplored.