WMAP and the generalized Chaplygin gas
We compare the WMAP temperature power spectrum and SNIa data to models with a generalized Chaplygin gas as dark energy. The generalized Chaplygin gas is a component with an exotic equation of state, p X = − A /ρ α X (a polytropic gas with negative constant and exponent). Our main result is that, res...
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| Main Author: | |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
8 July 2003
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| In: |
Journal of cosmology and astroparticle physics
Year: 2003, Issue: 7, Pages: 1-14 |
| ISSN: | 1475-7516 |
| DOI: | 10.1088/1475-7516/2003/07/005 |
| Online Access: | Verlag, Volltext: http://dx.doi.org/10.1088/1475-7516/2003/07/005 Verlag, Volltext: http://stacks.iop.org/1475-7516/2003/i=07/a=005 
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| Author Notes: | L. Amendola, F. Finelli, C. Burigana and D. Carturan |
| Summary: | We compare the WMAP temperature power spectrum and SNIa data to models with a generalized Chaplygin gas as dark energy. The generalized Chaplygin gas is a component with an exotic equation of state, p X = − A /ρ α X (a polytropic gas with negative constant and exponent). Our main result is that, restricting to a flat universe and to adiabatic pressure perturbations for the generalized Chaplygin gas, the constraints at 95% CL to the present equation of state w X = p X /ρ X and to the parameter α are−1 ≤ w X < −0.8, 0 ≤ α < 0.2, respectively. Moreover, we show that a Chaplygin gas (α = 1) is ruled out as a candidate for dark energy by our analysis at more than the 99.99% CL. A generalized Chaplygin gas appears much less likely as a unified dark matter candidate (Ω CDM = 0) than as a dark energy model, although its χ 2 is only two sigma away from the expected value. |
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| Item Description: | Gesehen am 17.11.2017 |
| Physical Description: | Online Resource |
| ISSN: | 1475-7516 |
| DOI: | 10.1088/1475-7516/2003/07/005 |