The dark universe future and singularities: The account of thermal and quantum effects

Abstract

© 2020 Elsevier B.V. The knowledge of the universe future is of fundamental importance for any advanced civilization. We study the future of the singular dark universe where thermal effects due to the Hawking radiation on the apparent horizon of the FRW universe are taken in the consideration. It is shown that the dark universe which ends up as finite-time Type I and Type III singularity or the infinite-time Little Rip singularity transits to the finite-time Type II singularity thanks to account of the thermal effects. However, Type II and IV singular universe does not change the qualitative behavior. The combined account of the quantum and thermal effects shows that depending on the specific features of the universe only one of the effects is dominant. When (conformal matter) quantum effects are dominant, the future singularity is usually removed while for dominant thermal effects the universe final state is Type II singularity.