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From the 1 of 24 linked papers with an AI index.

activity
20242026
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19 papers

gr-qc2026

The Schwarzschild Black Hole in an External Gravitational Tidal Field: the Quasinormal Spectrum

Dimitrios Giataganas, Alex Kehagias, Antonio Riotto

A black hole need not ring down in isolation, since a nearby companion can subject it to an external gravitational tide. We calculate how a quadrupole tide modifies the Schwarzschi…

hep-th2026

Thermal Origin of Black Hole Quasinormal Modes

D. Giataganas, G. F. Giudice, A. Kehagias +2

When a black hole rings after a merger, it emits gravitational waves at characteristic frequencies known as quasinormal modes (QNMs). In the eikonal limit, these modes are governed…

gr-qc2026

A Bound on the Dynamical Love Number

Alex Kehagias, Antonio Riotto

The paper derives a theoretical bound on the frequency dependence of the tidal deformability (Love number) of compact objects such as neutron stars and black holes, using the Schwa…

gr-qc2026

Radial Mirror Scattering and the QNM Convergence Region

Alex Kehagias, Antonio Riotto

We revisit the convergence region of the quasinormal modes expansion of Schwarzschild retarded Green functions from a radial scattering viewpoint. The tortoise coordinate admits a…

hep-th2026

Black Hole Photon Rings Saturate the Quantum Chaos Bound

D. Giataganas, G. F. Giudice, A. Kehagias +2

We study the quantum chaos bound in the photon ring region surrounding black holes. By evaluating the Lyapunov exponent associated with unstable null geodesics in a broad class of…

hep-ph2026

Standard Model Higgs Peaks: a Note on the Vacuum Instability during Inflation

G. Franciolini, A. Kehagias, A. Riotto

In the Standard Model, the Higgs potential develops an instability at high field values when the quartic self-coupling runs negative. Large quantum fluctuations during cosmic infla…