XV Black Holes Workshop

Session

Session 3 A

19 Dec 2022, 14:30

ISCTE - University Institute of Lisbon

101. A. Foschi: Using S2 motion to constrain a scalar field cloud around SgrA*

19/12/2022, 14:30

The motion of S2, one of the stars closest to the Galactic Center, has been well studied and used to set constraints on the compact object at the center of the Milky Way. This central object is well established to be a supermassive black hole but the nature of its environment is unknown. Here, we investigate the possibility that dark matter in the form of an ultralight scalar field clusters...

102. J. Calderón Bustillo: Measuring the direction of a black-hole gravitational recoil

19/12/2022, 14:45

Gravitational waves (GWs) carry linear momentum. As a consequence, due to the asymmetry of the GW emission, the remnant of a black hole of a black-hole merger can inherit a recoil speed, known as “kick”, which can exceed the scape velocity of the host environment. The magnitude of a black-hole kick has fundamental implications in black-hole formation and while its direction is key to...

103. F. Serrano: Superradiance and Hawking evaporation in the string axiverse

19/12/2022, 15:00

In the string axiverse scenario, light primordial black holes may spin up due to the Hawking emission of a large number of light (sub-MeV) axion-like particles (ALPs). We show that this may trigger superradiant instabilities associated with heavier ALPs during the black hole?s evolution, and study the coupled dynamics of superradiance and evaporation. We find, in particular, that the black...

104. M. Oi: Constraining regular black holes with S2 star data

19/12/2022, 15:15

Black-hole existence has been widely tested in several contexts, with all observations in agreement with general relativity (GR). However, GR predicts the presence of a curvature singularity at the black- hole core, where the theory breaks down. Consequently, there has recently been increased interest in studying regular black-hole geometries, i.e., objects that are completely regular...

105. C. Pasiecznik: Eikonal approximation in black hole dynamics and gravitational wave experiments

19/12/2022, 15:30

The Eikonal approximation has provided a simple approach to analyze the scattering angle of particles interacting with a large massive object. With the Eikonal approach, it is possible to study the quantum perturbative scattering amplitudes of a binary system interacting through graviton exchanges. We re- view the effective field theory treatment of general relativity and the higher order...

106. J. Pasiecznik: Prospects for gravitational wave detection with CubeSats

19/12/2022, 15:45

We explore the feasibility of using CubeSats for detecting Gravitational Waves (GW). Heavier black hole mergers are dominated by low-frequency emission, however terrestrial gravitational noise contributions prevent the use of ground based low-frequency GW detectors. We present the sources of such noise contributions and the argument for the use of space based low-frequency GW detectors. We...