Big rip avoidance via black holes production

Abstract

We consider a cosmological scenario in which the expansion of the Universe is dominated by phantom dark energy and black holes which condense out of the latter component. The mass of black holes decreases via Hawking evaporation and by accretion of phantom fluid but new black holes arise continuously whence the overall evolution can be rather complex. We study the corresponding dynamical system to unravel this evolution and single out scenarios where the big rip singularity does not occur.Comment: 16 pages, two figures. Key words. Cosmology, phantom energy, black holes. Sligthly extended version to be published in Gravitation and Cosmolog