activity
20242026
collaborators

6 papers

gr-qc2026

Axial Oscillations of Viscous Neutron Stars

Sofía Bussières, Jaime Redondo-Yuste, José Javier Ortega Gómez +1

The oscillation modes of stars play an important role in observations, and on the understanding of stellar stability properties. The role of viscosity in the oscillation modes of c…

gr-qc2026

Ringdown and lensing of triple systems

Vitor Cardoso, Giuseppe Ficarra, Jaime Redondo-Yuste +1

Triple systems have progressively been recognized as ubiquitous in our Universe and provide a good testing ground for wave generation and propagation in nontrivial environments. We…

gr-qc2025

Superradiant amplification by rotating viscous compact objects

Jaime Redondo-Yuste, Vitor Cardoso

We study fluctuations of rotating viscous stars, using the causal relativistic hydrodynamics of Bemfica, Disconzi, Kovtun, and Noronha. We derive, in a slow-rotation approximation,…

gr-qc2025

Ringdown nonlinearities in the eikonal regime

Bruno Bucciotti, Vitor Cardoso, Adrien Kuntz +2

The eikonal limit of black hole quasinormal modes (the large multipole limit ) can be realized geometrically as a next-to-leading order solution to the geometric optics…

gr-qc2025

Dynamical Lensing Tomography of Black Hole Ringdown

Zhen Zhong, Vitor Cardoso, Yifan Chen

Strong gravitational lensing occurs when photons pass through the vicinity of a black hole. We investigate this phenomenon in the context of a gravitational-wave event, specificall…

gr-qc2024

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…