3 papers
gr-qc2026
Gravitational electric-magnetic duality at the light ring and quasinormal mode isospectrality in effective field theories
Ibrahima Bah, Emanuele Berti, Valerio De Luca +2
Black hole perturbations are characterized by a superposition of damped exponentials known as quasinormal modes. In general relativity, the spectra of parity-even and parity-odd qu…
gr-qc2026
Gravitational Atoms from Topological Stars
Ibrahima Bah, Emanuele Berti, Bogdan Ganchev +2
We study the bound states of a massive scalar field around a topological star, and show that these are strictly normal modes. This yields a genuine gravitational atom, sharply dist…
hep-th2025
Holography of quarter-BPS AdS bubbles
Bogdan Ganchev, Anthony Houppe
We consider the quarter-BPS sector of the AdS/CFT duality, and provide a precise matching between specific CFT states and supergravity geometries beyond the linearized appr…