Supernova Constraints on Braneworld Dark Energy

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dc.creatorAlam, Ujjaini
dc.creatorSahni, Varun
dc.date2002-09-21
dc.date.accessioned2026-07-25T18:46:22Z
dc.descriptionBraneworld models of dark energy are examined in the light of observations of high redshift type Ia supernovae. Braneworld models admit several novel and even exotic possibilities which include: (i) The effective equation of state of dark energy can be more negative than in LCDM: $w \leq -1$; (ii) A class of braneworld models can encounter a `quiescent' future singularity at which the energy density and the Hubble parameter remain well behaved, but higher derivatives of the expansion factor ($\stackrel{..}{a}$, $\stackrel{...}{a}$ etc.) diverge when the future singularity is reached; (iii) The current acceleration of the universe is a {\em transient feature} in a class of models in which dark energy `disappears' after a certain time, giving rise to a matter dominated universe in the future. Since horizons are absent in such a space-time, a braneworld model with {\em transient acceleration} might help reconcile current supernova-based observations of an accelerating universe with the demands of string/M-theory. A maximum likelihood analysis reveals that braneworld models satisfy the stringent demands imposed by high redshift supernovae and a large region in parameter space agrees marginally better with current observations than LCDM. For instance, models with $w < -1 (> -1)$ provide better agreement with data than LCDM for $Ω_m \ggeq 0.3 (\lleq 0.25)$.
dc.descriptionRevTeX, 27 pages, 13 figures
dc.identifierhttps://arxiv.org/abs/astro-ph/0209443
dc.identifierhttp://arxiv.org/abs/astro-ph/0209443
dc.identifier.urihttps://dspace.dare.co.zw/handle/123456789/58401
dc.subjectAstrophysics
dc.subjectGeneral Relativity and Quantum Cosmology
dc.subjectHigh Energy Physics - Phenomenology
dc.subjectHigh Energy Physics - Theory
dc.titleSupernova Constraints on Braneworld Dark Energy
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