69 citations · 343 across the 17 of their papers we have counts for
18 papers
Spectral instabilities in the time domain
Taillte May, Adrien Kuntz, Nicola Franchini +2
We investigate the effect of a spectral instability on the time domain waveform using a one-dimensional double Pöschl-Teller model. By analytically following successive scatterings…
Semiclassical evolution of a dynamically formed spherical black hole with an inner horizon
Valentin Boyanov, David Hilditch, Artur Semião
In this work we obtain a numerical self-consistent spherical solution of the semiclassical Einstein equations representing the evaporation of a trapped region which initially has b…
Regular Vaidya solutions of effective gravitational theories
Valentin Boyanov, Raúl Carballo-Rubio
We initiate the study of the dynamics of spherically symmetric spacetimes beyond general relativity through exact solutions of the field equations of second-order effective gravita…
Towards a Non-singular Paradigm of Black Hole Physics
Raúl Carballo-Rubio, Francesco Di Filippo, Stefano Liberati +18
The study of regular black holes and black hole mimickers as alternatives to standard black holes has recently gained significant attention, driven both by the need to extend gener…
The dynamical response of viscous objects to gravitational waves
Valentin Boyanov, Vitor Cardoso, Kostas D. Kokkotas +1
We study the dynamical response of viscous materials to gravitational waves, in the context of a fully relativistic theory of fluid dynamics. For the first time, we calculate oscil…
On destabilising quasi-normal modes with a radially concentrated perturbation
Valentin Boyanov
In this work we explore some aspects of the spectral instability of back hole quasi-normal modes, using a specific model as an example. The model is that of a small bump perturbati…
Pseudospectrum of de Sitter black holes
Kyriakos Destounis, Valentin Boyanov, Rodrigo Panosso Macedo
Pseudospectral analyses have broadened our understanding of ringdown waveforms from binary remnants, by providing insight into both the stability of their characteristic frequencie…
Structural aspects of the anti-de Sitter black hole pseudospectrum
Valentin Boyanov, Vitor Cardoso, Kyriakos Destounis +2
Black holes in anti-de Sitter spacetime provide an important testing ground for both gravitational and field-theoretic phenomena. In particular, the study of perturbations can be u…
After collapse: On how a physical vacuum can change the black hole paradigm
Julio Arrechea, Carlos Barceló, Valentin Boyanov
Standard General Relativity assumes that, in the absence of classical matter sources, spacetime is empty. This chapter considers and analyses the new behaviours of the gravitationa…
Vacuum polarisation and regular gravitational collapse
Valentin Boyanov
It is the goal of this thesis to revisit and revise the problem of black hole formation and evolution in semiclassical gravity -- a theory in which spacetime is treated classically…
Pseudospectrum of horizonless compact objects: a bootstrap instability mechanism
Valentin Boyanov, Kyriakos Destounis, Rodrigo Panosso Macedo +2
Recent investigations of the pseudospectrum in black hole spacetimes have shown that quasinormal mode frequencies suffer from spectral instabilities. This phenomenon may severely a…
Warp Drive Aerodynamics
Carlos Barceló, Valentin Boyanov, Luis J. Garay +2
In this work we analyse the potential for a warp drive spacetime to develop instabilities due to the presence of quantum matter. Particularly, we look for points of infinite bluesh…
Way down in the hole... and up again
Valentin Boyanov
I argue that an approach which uses an appropriate admixture of both classical and semiclassical effects is essential for understanding the ultimate fate of gravitational collapse…
Classical mass inflation vs semiclassical inner horizon inflation
Carlos Barceló, Valentin Boyanov, Raúl Carballo-Rubio +1
We analyse the geometry of a spherically symmetric black hole with an inner and outer apparent horizon which is perturbed by spherical null shells of matter. On a classical level w…
Black hole inner horizon evaporation in semiclassical gravity
Carlos Barceló, Valentin Boyanov, Raúl Carballo-Rubio +1
In this work we analyse the backreaction of a quantum field on a spherically symmetric black hole geometry with an inner horizon, i.e. an internal boundary of the trapped region. W…
Vacuum semiclassical gravity does not leave space for safe singularities
Julio Arrechea, Carlos Barceló, Valentin Boyanov +1
General relativity predicts its own demise at singularities, but also appears to conveniently shield itself from the catastrophic consequences of such singularities, making them sa…
Asymptotic horizon formation, spacetime stretching and causality
Carlos Barceló, Valentin Boyanov, Raúl Carballo-Rubio +1
In this work we analyse asymptotically flat, spherically symmetric spacetimes in which an event horizon is present without any trapped surfaces. We identify two types of such space…
Semiclassical gravity effects near horizon formation
Carlos Barceló, Valentin Boyanov, Raúl Carballo-Rubio +1
We study the magnitude of semiclassical gravity effects near the formation of a black-hole horizon in spherically-symmetric spacetimes. As a probe for these effects we use a quanti…