Scalar perturbations in the late Universe: viability of the Chaplygin gas models
- Departamento de Física, Universidade da Beira Interior, 6200 Covilhã (Portugal)
- Department of Theoretical Physics, Odessa National University, Dvoryanskaya st. 2, Odessa 65082 (Ukraine)
- Department of Theoretical Physics, University of the Basque Country UPV/EHU, P.O. Box 644, 48080 Bilbao (Spain)
- Astronomical Observatory, Odessa National University, Dvoryanskaya st. 2, Odessa 65082 (Ukraine)
We study the late-time evolution of the Universe where dark energy (DE) is parametrised by a modified generalised Chaplygin gas (mGCG) on top of cold dark matter (CDM) . We also take into account the radiation content of the Universe. In this context, the late stage of the evolution of the universe refers to the epoch where CDM is already clustered into inhomogeneously distributed discrete structures (galaxies, groups and clusters of galaxies). Under these conditions, the mechanical approach is an adequate tool to study the Universe deep inside the cell of uniformity. To be more accurate, we study scalar perturbations of the Friedmann-Lemaȋtre-Robertson-Walker metric due to inhomogeneities of CDM as well as fluctuations of radiation and mGCG, the later driving the late-time acceleration of the universe. Our analysis applies as well to the case where mGCG plays the role of DM and DE . We select the sets of parameters of the mGCG that are compatible with the mechanical approach. These sets define prospective mGCG models. By comparing the selected sets of models with some of the latest observational data results, we conclude that the mGCG is in tight agreement with those observations particularly for a mGCG playing the role of DE and DM.
- OSTI ID:
- 22525119
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2015, Issue 12; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
Similar Records
Late time solutions for inhomogeneous {Lambda}CDM cosmology, their characterization, and observation
Are dark energy models with variable EoS parameter w compatible with the late inhomogeneous Universe?