9 papers
Assessing the stability of ultracompact spinning boson stars with nonlinear evolutions
Tamara Evstafyeva, Nils Siemonsen, William E. East
We reinvestigate the stability properties of ultracompact spinning boson stars with a stable light ring using fully nonlinear 3+1 and 2+1 numerical relativity simulations and two d…
Ultralight boson constraints from gravitational wave observations of spinning binary black holes
P. S. Aswathi, William E. East, Nils Siemonsen +2
In the presence of an ultralight scalar or vector boson, a spinning black hole will be spun down through the superradiant instability. We use spin measurements from gravitational w…
Nonlinear evolution of the ergoregion instability: Turbulence, bursts of radiation, and black hole formation
Nils Siemonsen, William E. East
Spacetimes with an ergoregion that is not connected to a horizon are linearly unstable. While the linear regime has been studied in a number of settings, little is known about the…
Implications of GW241011 for rotating exotic compact objects
N. V. Krishnendu, Tamara Evstafyeva, Aditya Vijaykumar +17
A number of theoretical proposals have been made for horizonless compact objects with masses and spins similar to those of black holes. While gravitational wave signatures from the…
Periodic Cosmic String Formation and Dynamics
Michael A. Fedderke, Junwu Huang, Nils Siemonsen
We study string formation and dynamics in a scalar field theory with a global symmetry. If a scalar field is initially displaced from the minimum of a wine-bottle poten…
Search for continuous gravitational wave signals from luminous dark photon superradiance clouds with LVK O3 observations
Lorenzo Mirasola, Cristina Mondino, Francesco Amicucci +10
Superradiance clouds of kinetically-mixed dark photons around spinning black holes can produce observable multi-messenger electromagnetic and gravitational wave signals. The cloud…