Bound states of the Dirac equation on Kerr spacetime

Dolan, Sam R.; Dempsey, David

doi:10.1088/0264-9381/32/18/184001

Cited by 52 publications

(67 citation statements)

References 104 publications

(264 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar computations for the energy spectrum of bounded Dirac fields in Kerr spacetime can be found in[94] 9. See[97,98] which point out a missing factor of 1/2 in Detweiler's original computation.…”

mentioning

confidence: 52%

Probing ultralight bosons with binary black holes

2019

View full text Add to dashboard Cite

We study the gravitational-wave (GW) signatures of clouds of ultralight bosons around black holes (BHs) in binary inspirals. These clouds, which are formed via superradiance instabilities for rapidly rotating BHs, produce distinct effects in the population of BH masses and spins, and a continuous monochromatic GW signal. We show that the presence of a binary companion greatly enriches the dynamical evolution of the system, most remarkably through the existence of resonant transitions between the growing and decaying modes of the cloud (analogous to Rabi oscillations in atomic physics). These resonances have rich phenomenological implications for current and future GW detectors. Notably, the amplitude of the GW signal from the clouds may be reduced, and in many cases terminated, much before the binary merger. The presence of a boson cloud can also be revealed in the GW signal from the binary through the imprint of finite-size effects, such as spin-induced multipole moments and tidal Love numbers. The time dependence of the cloud's energy density during the resonance leads to a sharp feature, or at least attenuation, in the contribution from the finite-size terms to the waveforms. The observation of these effects would constrain the properties of putative ultralight bosons through precision GW data, offering new probes of physics beyond the Standard Model. arXiv:1804.03208v2 [gr-qc]

show abstract

mentioning

confidence: 52%

Probing ultralight bosons with binary black holes

2019

View full text Add to dashboard Cite

show abstract

“…Here, Φ is a complex scalar field; Ψ is a Dirac 4-spinor, with four complex components;/ D ≡ γ µD µ , where γ µ are the curved spacetime gamma matrices,D µ = ∂ µ − Γ µ is the spinor covariant derivative and Γ µ are the spinor connection matrices [19]; A is a complex 4-potential, with the field strength F = dA. In all cases, µ > 0 corresponds to the mass of the field(s).…”

Section: The Modelmentioning

confidence: 99%

“…In all cases, µ > 0 corresponds to the mass of the field(s). For the scalar and Proca fields, the overbar denotes complex conjugation; Ψ denotes the Dirac conjugate [19].…”

Section: The Modelmentioning

confidence: 99%

Asymptotically flat spinning scalar, Dirac and Proca stars

et al. 2019

View full text Add to dashboard Cite

Einstein's gravity minimally coupled to free, massive, classical fundamental fields admits particle-like solutions. These are asymptotically flat, everywhere non-singular configurations that realise Wheeler's concept of a geon: a localised lump of self-gravitating energy whose existence is anchored on the nonlinearities of general relativity, trivialising in the flat spacetime limit. In [1] the key properties for the existence of these solutions (also referred to as stars or self-gravitating solitons) were discussed -which include a harmonic time dependence in the matter field -, and a comparative analysis of the stars arising in the Einstein-Klein-Gordon, Einstein-Dirac and Einstein-Proca models was performed, for the particular case of static, spherically symmetric spacetimes. In the present work we generalise this analysis for spinning solutions. In particular, the spinning Einstein-Dirac stars are reported here for the first time. Our analysis shows that the high degree of universality observed in the spherical case remains when angular momentum is allowed. Thus, as classical field theory solutions, these self-gravitating solitons are rather insensitive to the fundamental fermionic or bosonic nature of the corresponding field, displaying similar features. We describe some physical properties and, in particular, we observe that the angular momentum of the spinning stars satisfies the quantisation condition J = mN, for all models, where N is the particle number and m is an integer for the bosonic fields and a half-integer for the Dirac field. The way in which this quantisation condition arises, however, is more subtle for the non-zero spin fields.

show abstract

“…(8) in the text, we see that if ω R < mΩ H the mode will appear to propagate in the opposite direction and therefore A H will swap places with the 0 on the left of Eq. (18). QBSs are defined by the condition A in = 0.…”

Section: Wkb Formula For Qbs Frequenciesmentioning

confidence: 99%

Black Hole Quasibound States from a Draining Bathtub Vortex Flow

et al. 2018

View full text Add to dashboard Cite

Quasinormal modes are a set of damped resonances that describe how an excited open system is driven back to equilibrium. In gravitational physics these modes characterize the ringdown of a perturbed black hole, e.g., following a binary black hole merger. A careful analysis of the ringdown spectrum reveals the properties of the black hole, such as its angular momentum and mass. In more complex gravitational systems, the spectrum might depend on more parameters and hence allows us to search for new physics. We present a hydrodynamic analog of a rotating black hole that illustrates how the presence of extra structure affects the quasinormal mode spectrum. The analogy is obtained by considering wave scattering on a draining bathtub vortex flow. We show that due to vorticity of the background flow, the resulting field theory corresponds to a scalar field on an effective curved spacetime which acquires a local mass in the vortex core. The obtained quasinormal mode spectrum exhibits long-lived trapped modes, commonly known as quasibound states. Our findings can be tested in future experiments building upon recent successful implementations of analog rotating black holes.

show abstract

Bound states of the Dirac equation on Kerr spacetime

Cited by 52 publications

References 104 publications

Probing ultralight bosons with binary black holes

Probing ultralight bosons with binary black holes

Asymptotically flat spinning scalar, Dirac and Proca stars

Black Hole Quasibound States from a Draining Bathtub Vortex Flow

Contact Info

Product

Resources

About