collaborators

7 papers

gr-qc2025

Price's law from quasinormal modes

Paolo Arnaudo, Benjamin Withers

We show that Price's power-law tail for perturbations of Schwarzschild, as , can be obtained from a sum of Schwarzschild-de Sitter quasinormal modes in…

hep-th2025

Stable evolution of relativistic hydrodynamics order-by-order in gradients

Michal P. Heller, Alexandre Serantes, Michał Spaliński +1

We provide a systematic framework for solving the initial value problem for relativistic hydrodynamics formulated as a gradient expansion. Secular growth is handled by a suitable c…

gr-qc2025

Beyond quasinormal modes: a complete mode decomposition of black hole perturbations

Paolo Arnaudo, Javier Carballo, Benjamin Withers

We show that retarded Green's functions of black hole spacetimes can be expressed as a convergent mode sum everywhere in spacetime. At late times a quasinormal mode sum converges,…

gr-qc2025

Transients in black hole perturbation theory

Jérémy Besson, Javier Carballo, Christiana Pantelidou +1

Black hole quasinormal modes arise as eigenmodes of a non-normal Hamiltonian and consequently they do not obey orthogonality relations with respect to commonly used inner products,…

hep-th2025

QNM orthogonality relations for AdS black holes

Paolo Arnaudo, Javier Carballo, Benjamin Withers

We present orthogonality relations for quasinormal modes of a wide class of asymptotically AdS black holes. The definition is obtained from a standard product, modified by a CPT op…

gr-qc2025

Non-modal effects in black hole perturbation theory: Transient Superradiance

Javier Carballo, Christiana Pantelidou, Benjamin Withers

We study the non-modal stability of black hole spacetimes under linear perturbations. We show that large-amplitude growth can occur at finite time, despite asymptotic decay of line…