Observational constraints on late-time {lambda}(t) cosmology
- Instituto de Fisica, Universidade Federal da Bahia, Salvador-BA, 40210-340 (Brazil)
- Departamento de Astronomia, Observatorio Nacional, Rio de Janeiro-RJ, 20921-400 (Brazil)
The cosmological constant {lambda}, i.e., the energy density stored in the true vacuum state of all existing fields in the Universe, is the simplest and the most natural possibility to describe the current cosmic acceleration. However, despite its observational successes, such a possibility exacerbates the well-known {lambda} problem, requiring a natural explanation for its small, but nonzero, value. In this paper we study cosmological consequences of a scenario driven by a varying cosmological term, in which the vacuum energy density decays linearly with the Hubble parameter, {lambda}{proportional_to}H. We test the viability of this scenario and study a possible way to distinguish it from the current standard cosmological model by using recent observations of type Ia supernova (Supernova Legacy Survey Collaboration), measurements of the baryonic acoustic oscillation from the Sloan Digital Sky Survey, and the position of the first peak of the cosmic microwave background angular spectrum from the three-year Wilkinson Microwave Anisotropy Probe.
- OSTI ID:
- 21249999
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 77, Issue 8; Other Information: DOI: 10.1103/PhysRevD.77.083504; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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