Departament d'Astronomia i Astrofísica
Universitat de València |

Accretion in spacetimes with the cosmological constant

*Patryk Mach*

*Jagiellonian University, Institute of Physics, Cracòvia, Polònia*

*Seminari del departament d'Astronomia i AstrofÃsica*

*Dijous 21 novembre 2013*

*12:00*

**Resum**

*I will discuss spherical, isothermal and polytropic steady accretion models in the presence of the cosmological constant. Exact solutions are found for a class of isothermal fluids, assuming the test gas approximation. These results can have cosmological connotation, through the Einstein–Straus vacuole model of embedding local structures into FLRW spacetimes. In particular, one infers that steady accretion would not exist in the late phases of the Penrose’s scenario of the evolution of the Universe. If time permits, stability of the obtained solutions will be also discussed.*