106 citations · 267 across the 14 of their papers we have counts for
14 papers
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…
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…
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…
Microstrata
Bogdan Ganchev, Stefano Giusto, Anthony Houppe +2
Microstrata are the non-extremal analogues of superstrata: they are smooth, non-extremal (non-BPS) solitonic solutions to IIB supergravity whose deep-throat limits approximate blac…
On Supersymmetric Multipole Ratios
Bogdan Ganchev, Daniel R. Mayerson
Four-dimensional supersymmetric black holes are static and so have all vanishing multipoles. Nevertheless, it is possible to define finite multipole ratios for these black holes, b…
Black Hole Multipoles in Higher-Derivative Gravity
Pablo A. Cano, Bogdan Ganchev, Daniel R. Mayerson +1
We consider a broad family of higher-derivative extensions of four-dimensional Einstein gravity and study the multipole moments of rotating black holes therein. We carefully show t…
Elliptical and Purely NS Superstrata
Bogdan Ganchev, Anthony Houppe, Nicholas P. Warner
We analyze the BPS equations in the ``superstratum sector'' of three-dimensional gauged supergravity. We obtain multi-parameter supersymmetric solutions that include elliptical def…
AdS holography for non-BPS geometries
Bogdan Ganchev, Stefano Giusto, Anthony Houppe +1
By using the approach introduced in arXiv:2107.09677 we construct non-BPS solutions of 6D supergravity coupled to two tensor multiplets as a perturbation of AdS$_3\times S^…
New Superstrata from Three-Dimensional Supergravity
Bogdan Ganchev, Anthony Houppe, Nicholas P. Warner
We find a two-parameter family of {\it generalized superstrata} that emerge as smooth, supersymmetric solutions in three-dimensional gauged supergravity coupled to additional scala…
Q-Balls Meet Fuzzballs: Non-BPS Microstate Geometries
Bogdan Ganchev, Anthony Houppe, Nicholas Warner
We construct a three-parameter family of non-extremal microstate geometries, or "microstrata," that are dual to states and deformations of the D1-D5 CFT. These families are non-ext…
Plausible scenario for a generic violation of the weak cosmic censorship conjecture in asymptotically flat four dimensions
Felicity C. Eperon, Bogdan Ganchev, Jorge E. Santos
We present a plausible counterexample to the weak cosmic censorship conjecture in the four-dimensional Einstein-Scalar theory with asymptotically flat boundary conditions. Our setu…
Scalar Hairy Black Holes in Four Dimensions are Unstable
Bogdan Ganchev, Jorge E. Santos
We present a numerical analysis of the stability properties of the black holes with scalar hair constructed by Herdeiro and Radu. We prove the existence of a novel gauge where the…
Superradiant instability in AdS
Bogdan Ganchev
The phenomenon of superradiance in the context of asymptotically global AdS spacetimes is investigated with particular accent on its effect on the stability of the systems under co…
Three-particle Complexes in Two-Dimensional Semiconductors
Bogdan Ganchev, Neil Drummond, Igor Aleiner +1
We map the three-body problem in two dimensions onto one particle in a three dimensional potential treatable by a purposely-developed boundary-matching-matrix method. We evaluate b…