Seminar “Modern Mathematical Physics”

Date and Time: Tuesday, 23 June 2020, at 1:00 PM

Venue: Online conference on Zoom, Bogoliubov Laboratory of Theoretical Physics

Seminar topic: «Soliton stars, boson constellations and spinning black holes with hairs»

Speaker: Yakov Shnir

Abstract:

We study new families of stationary rotating axially symmetric soliton stars in a complex scalar field theory minimally coupled to Einstein gravity, and spinning hairy black holes with event horizon, which represent solutions of the Einstein-Skyrme model in the Kerr spacetime. We found that the spinning axially symmetric cloudy solutions of the model also exist in the regular asymptotically flat space-time. The latter congurations are similar to the usual rotating boson stars, which, in the flat space limit are linked to the axially symmetric Q-balls. We found that in both cases the solutions exist for some restricted range of values of the angular frequency and possess a quantized angular momentum. Considering similar solution in the O(3) sigma model, we show that, depending on the values of the parameters of the model and the Hawking temperature, the branch structure of the corresponding cloudy solutions varies from the usual inspirraling pattern, which is typical for the boson stars, to the two branch structure, similar to that of the black holes with Skyrme hairs. As another examples of spinning black holes with synchronized hairs we consider families of parity-odd solutions of the Einstein-Klein-Gordon model. Finally, we discuss Dirac stars and compare their properties with the usual boson stars.