**1 June 2021***Current trends in gravitation Seminar*

Location: **University Oldenburg - Online **

When: 1.6.2021, 16:15 h**Speaker**: Yakov Shnir (BLTP Dubna)

**Title**: Multicomponent boson stars and other soliton stars

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.