6533b82cfe1ef96bd128ff2a
RESEARCH PRODUCT
Nonlinear dynamics of spinning bosonic stars: formation and stability
Eugen RaduPablo Cerdá-duránNicolas Sanchis-gualMiguel ZilhãoJosé A. FontF. Di GiovanniCarlos A. R. HerdeiroCarlos A. R. Herdeirosubject
High Energy Physics - TheoryAngular momentumFOS: Physical sciencesGeneral Physics and AstronomyPerturbation (astronomy)General Relativity and Quantum Cosmology (gr-qc)Astrophysics::Cosmology and Extragalactic Astrophysics01 natural sciencesInstabilityGeneral Relativity and Quantum CosmologyGravitationsymbols.namesakeGeneral Relativity and Quantum Cosmology0103 physical sciencesGravitational collapseAstrophysics::Solar and Stellar AstrophysicsEinstein010306 general physicsAstrophysics::Galaxy AstrophysicsBosonHigh Energy Astrophysical Phenomena (astro-ph.HE)PhysicsBoson starsStarsClassical mechanicsHigh Energy Physics - Theory (hep-th)symbolsAstrophysics::Earth and Planetary AstrophysicsAstrophysics - High Energy Astrophysical PhenomenaStabilitydescription
We perform numerical evolutions of the fully non-linear Einstein-(complex, massive)Klein-Gordon and Einstein-(complex)Proca systems, to assess the formation and stability of spinning bosonic stars. In the scalar/vector case these are known as boson/Proca stars. Firstly, we consider the formation scenario. Starting with constraint-obeying initial data, describing a dilute, axisymmetric cloud of spinning scalar/Proca field, gravitational collapse towards a spinning star occurs, via gravitational cooling. In the scalar case the formation is transient, even for a non-perturbed initial cloud; a non-axisymmetric instability always develops ejecting all the angular momentum from the scalar star. In the Proca case, by contrast, no instability is observed and the evolutions are compatible with the formation of a spinning Proca star. Secondly, we address the stability of an existing star, a stationary solution of the field equations. In the scalar case, a non-axisymmetric perturbation develops collapsing the star to a spinning black hole. No such instability is found in the Proca case, where the star survives large amplitude perturbations; moreover, some excited Proca stars decay to, and remain as, fundamental states. Our analysis suggests bosonic stars have different stability properties in the scalar/vector case, which we tentatively relate to their toroidal/spheroidal morphology. A parallelism with instabilities of spinning fluid stars is briefly discussed.
year | journal | country | edition | language |
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2019-07-29 |