9 papers
Axion Hair and Pulsar Electrodynamics: modelling, discharge dynamics, and particle-in-cell simulations
Samuel J. Witte, Andrea Caputo, Stefan Stelzl +3
In a companion paper, we demonstrated that static axion field gradients sourced by dense nuclear matter (\emph{axion hair}) can dominate the near-field electrodynamics of old rotat…
From S2 to LISA: Astrometric Bounds on Extreme-Mass-Ratio Inspirals and Bursts
Andrea Caputo, Valerie Domcke
Stellar orbits around the massive black hole at the center of our galaxy provide a unique local probe of the compact-object population in the Galactic Centre and, consequently, of…
Is S301 the Captured Companion of the Hypervelocity Star S5-HVS1?
Andrea Caputo, Giovanni Maria Tomaselli
Stellar binary disruptions through the Hills mechanism produce two fossils: a hypervelocity star (HVS), and a star tightly bound to the supermassive black hole. Among known galacti…
GUEST: Gravitational Universe Exploration with Satellite Tracking. A passive satellite laser-ranging mission for the dark gravitational Universe
Diego Blas, Aurélien Hees, F. Javier Atapuerca +78
GUEST is a space mission concept whose central objective is the detection of gravitational waves (GWs) in the microhertz band -- a physics-rich frequency window that no other prese…
Evolution of Binaries Under Stochastic Perturbations
Andrea Caputo, Giovanni Maria Tomaselli, Chris Hamilton
We develop a general Fokker-Planck framework describing the dynamical evolution of Keplerian binaries subjected to stochastic perturbations. The formalism provides an algorithmic w…
Simulating Axion Electrodynamics in Magnetized Plasmas: Energy transfer in the inhomogeneous and strongly varying limit
Fabrizio Corelli, Estanis Utrilla Ginés, Enrico Cannizzaro +2
In this work we study the electromagnetic response induced by axions in a magnetized plasma, focusing specifically on characterizing energy transfer and energy losses from the ambi…
Constraints on light QCD and CP-violating axions from the death line of rotation-powered pulsars
Samuel J. Witte, Andrea Caputo, Stefan Stelzl +3
Dense nuclear matter can modify the effective potential of axions, displacing them from their vacuum minimum, and sourcing large external field gradients (``axion hair"). In the ca…
Probing dense environments around Sgr A* with S-stars dynamics
Giovanni Maria Tomaselli, Andrea Caputo
The orbits of stars around Sgr A*, the Milky Way's supermassive black hole, provide a unique laboratory for testing its environment with unprecedented precision. In this work, we c…
Superradiance Constraints from GW231123
Andrea Caputo, Gabriele Franciolini, Samuel J. Witte
Gravitational wave observations have recently revealed with high significance, and high precision, the existence of rapidly rotating black holes, allo…