Strong Gravity

Charged boson stars serve as models for exploring how self-interaction and electromagnetic charge influence the stability and evolution of compact objects. In this seminar, I will present results from numerical relativity simulations identifying a critical charge that serves as a threshold for stable configurations.

We present a large family of twisting and expanding solutions to the Einstein-Maxwell equations of algebraic type D, for which the two double principal null directions (PNDs) of the Weyl tensor are not aligned with the null eigendirections of the Faraday tensor. In addition to systematically deriving this new class, we present its various metric forms and convenient parameterizations.

Gravitational-wave (GW) observations have significantly advanced our understanding of stellar-origin compact objects. Current detectors could, in principle, also observe exotic compact objects (ECOs) acting as black-hole mimickers and interacting only gravitationally with visible matter.

This talk presents two distinct problems in gravitational physics that are connected through the use of solution-generating techniques within Einstein–Maxwell–scalar theory. First, we construct new vacuum solutions of Einstein’s equations starting from electrovacuum configurations embedded in external electromagnetic backgrounds.

In early May 2026 we received the visits of our collaborators Nico Sanchis Gual, Isa Cordero, Gabriele Palloni, Claudio Lazarte (Valencia, Spain), members of the NewFunFiCO network, as well as Carolina Benone (UFPA, Brazil) and Carlos Joaquin (UNAM, Mexico), who joined us to celebrate the successful Ph.D. exam of Etevaldo Costa.