Superradiant instabilities by accretion disks in scalar-tensor theories
arXiv:2204.09335 · doi:10.1103/PhysRevD.106.024007
Abstract
We study the superradiant instability in scalar-tensor theories of gravitation, where matter outside a black hole provides an effective mass to the scalar degree of freedom of the gravitational sector. We discuss this effect for arbitrarily spinning black holes and for realistic models of truncated thin and thick accretion disks (where the perturbation equations are nonseparable), paying particular attention to the role of hot coronal flows in the vicinity of the black hole. The system qualitatively resembles the phenomenology of plasma-driven superradiant instabilities in General Relativity. Nevertheless, we show that the obstacles hampering the efficiency of plasma-driven superradiant instabilities in General Relativity can be circumvented in scalar-tensor theories. We find a wide range of parameter space where superradiant instabilities can be triggered in realistic scenarios, and discuss the constraints on scalar-tensor theories imposed by this effect. In particular, we argue that the existence of highly spinning accreting black holes is in tension with some scalar-tensor alternatives to the dark energy, e.g. symmetron models with screening.
13 pages, 6 figures
References in corpus (8)
- The Confrontation between General Relativity and Experiment
- Modelling the behaviour of accretion flows in X-ray binaries
- Can environmental effects spoil precision gravitational-wave astrophysics?
- Black holes as particle detectors: evolution of superradiant instabilities
- Strong-field Gravity Tests with the Double Pulsar
- Environmental Effects for Gravitational-wave Astrophysics
- Superradiance in massive vector fields with spatially varying mass
- Interaction of the accretion flows in corona and disk near the black hole in AGN