A theoretician's analysis of the supernova data and the limitations in determining the nature of dark energy
By Thanu Padmanabhan, T. R. Choudhury. 2002
280 citations recorded by the source corpus.
Current cosmological observations show a strong signature of the existence of a dark energy component with negative pressure. The most obvious candidate for this dark energy is the cosmological constant (with the equationof state w X = p/ρ = -1), which, however, raises several theoretical difficulties. This has led to models for a dark energy component that evolves with time. We discuss certain questions related to the determination of the nature of the dark energy component from observations of high-redshift supernovae. The main results of our analysis are as follows. (i) Even if the precise value of w X is known from observations, it is not possible to determine the nature of the unknown dark energy source using only kinematical and geometrical measurements. We have given explicit examples to show that different types of sources can give rise to a given w X . (ii) Although the full data set of supernova observations (which are currently available) strongly rule out models without dark energy, the high- (z > 0.25) and low- (z < 0.25) redshift data sets, individually, admit decelerating models with zero dark energy. Any possible evolution in the absolute magnitude of the supernovae, if detected, might allow the decelerating models to be consistent with the data. (iii) We have introduced two parameters, which can be obtained entirely from theory, to study the sensitivity of the luminosity distance on w X . Using these two parameters, we have argued that although one can determine the present value of w X accurately from the data, one cannot constrain the evolution of w X .
Subfields: Astronomy and Astrophysics
View Paper: https://www.semanticscholar.org/paper/b0c84a9b911b1aa90102cfb177115eedb4a07aea
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In Astronomy and Astrophysics
Citations in the corpus
- Latest supernova data in the framework of the generalized Chaplygin gas model (2004, background): “Recently Choudhury & Padmanabhan (2003) have analyzed the supernova data with currently available 194 data points[see also Padmanabhan & Choudhury (2003)] and shown that it yields relevant constraints on some cosmological parameters.”
- WMAP constraints on low redshift evolution of dark energy (2004, methodology): “The results we obtain are consistent with similar analysis in other papers (Amendola & Quercellini 2003; Jimenez 2003; Jimenez et al. 2003; Padmanabhan & Choudhury 2003; Alam et al. 2004a,b; Bassett 2004; Bassett et al. 2004; Corasaniti et al. 2004; Choudhury & Padmanabhan 2004; Daly & Djorgovski…”
- Generalized Chaplygin gas as a unified scenario of dark matter/energy: Observational constraints (2004, background): “…Zhu matter” (Turner and White 1997; Zhu, Fujimoto and Tatsumi 2001; Lima and Alcaniz 2002; Lima, Cunha and Alcaniz 2003; Gong 2004; Chen 2004), and quintessence (Ratra and Peebles 1988; Caldwell et al. 1998; Sahni and Wang 2000; Gong 2002; Sahni et al. 2003; Padmanabhan and Choudhury 2003) etc..”
- Jerk, snap, and the cosmological equation of state (2003, unknown): “Dated: 24 March 2004; LATEX-ed 24 March 2022 PACS numbers: gr-qc/0309109”
- Cosmological parameters from supernova observations: A critical comparison of three data sets (2003, background): “…2002; Minty, Heavens, & Hawkins 2002; Maor et al. 2002; Weller & Albrecht 2002; Gerke & Efstathiou 2002; Rowan-Robinson 2002; Linder & Jenkins 2003; Padmanabhan & Choudhury 2003; Visser 2004; Caresia, Matarrese, & Moscardini 2004; Alcaniz 2004; Wang & Mukherjee 2004; Novello, Perez Bergliaffa, &…”
- The effect of inhomogeneous expansion on the supernova observations (2006, background): “The early supernova data had a discrepancy between the Hubble parameter deduced from the low redshift sample and the one deduced from the high redshift sample [31], but it seems to have vanished from the latest supernova data [32].”