In this work, we study the relation of the eikonal quasinormal modes (EQNMs) and the unstable fundamental photon orbits (UFPOs) in the Kerr-Newman spacetime. We find that in the eikonal limit the gravitational and electromagnetic perturbations of the Kerr-Newman black hole are naturally decoupled, and a single one-dimensional Schrodinger-like equation encoding the QNM spectrum can be derived.
Despite of the weak couplings to normal matter, light axion fields can be significantly sourced by neutron stars, leaving potentially detectable signals in gravitational waves from binary neutron star inspirals. In this talk, I am going to talk about how the axions affect the inspiral waveform, and to report a recent search for such axions with GW170817.
Abstract: The detection of gravitational waves from extreme-mass-ratio inspirals (EMRIs) with upcoming space-borne detectors will allow for unprecedented tests of general relativity in the strong-field regime. Aside from assessing whether black holes are unequivocally described by the Kerr metric, they may place constraints on the degree of spacetime symmetry.
It was recently shown that a broad class of gravity theories allows for spontaneous scalarization of black holes, letting these objects grow “scalar hair” once certain conditions are met and to remain “bald” otherwise.
A call for a 1 year postdoctoral grant in High Energy Physics, within the research grant “From Higgs phenomenology to the unification of fundamental interactions", PTDC / FIS-PAR / 31000/2017, is open from the 19th of April to the 14th of May 2021. See the eracareers announcement (in Portuguese and English) here.
In this talk I will first review a few intriguing properties of black hole quasinormal modes in the eikonal limit or in the near extremal limit (for the black hole). After that I will show how to relate quasinormal modes to the black hole shadows, and how to formulate a test for such relation.
Our group coordinated the "Numerical Relativity and High Energy Physics" IRSES network (2012-2015). Here is a list of the global network meetings organized:
