Axions comprise a broad class of particles that can play a major role in explaining the
unknown aspects of cosmology. They are also well-motivated within high energy physics …

Abstract The Laser Interferometer Space Antenna (LISA) has the potential to reveal wonders
about the fundamental theory of nature at play in the extreme gravity regime, where the …

70 AIM, UMR 7158, CEA/DRF, CNRS, Université Paris Diderot, Irfu/Service d'Astrophysique,
Centre de Saclay, FR-91191 Gif-sur-Yvette, France

In this paper, which is of programmatic rather than quantitative nature, we aim to further
delineate and sharpen the future potential of the LISA mission in the area of fundamental …

One century after its formulation, Einstein's general relativity (GR) has made remarkable
predictions and turned out to be compatible with all experimental tests. Most of these tests …

Ultralight bosons can affect the dynamics of spinning black holes (BHs) via superradiant
instability, which can lead to a time evolution of the supermassive BH shadow. We study …

Black hole superradiance is a powerful probe of light, weakly coupled hidden sector
particles. Many candidate particles, such as axions, generically have self-interactions that …

We present a family of solutions of Einstein's gravity minimally coupled to a complex,
massive scalar field, describing asymptotically flat, spinning black holes with scalar hair and …

Ultralight axions (ULAs) with masses in the range 1 0-33 eV≤ ma≤ 1 0-20 eV are motivated
by string theory and might contribute to either the dark-matter or dark-energy densities of the …

Ultralight bosons can induce superradiant instabilities in spinning black holes, tap** their
rotational energy to trigger the growth of a bosonic condensate. Possible observational …