Open AccessIs there supernova evidence for dark energy metamorphosis?
Author(s) -
Alam Ujjaini,
Sahni Varun,
Deep Saini Tarun,
Starobinsky A. A.
Publication year - 2004
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2004.08189.x
Subject(s) - physics , dark energy , supernova , equation of state , astrophysics , metamorphosis , mathematical physics , cosmology , quantum mechanics , botany , larva , biology
We reconstruct the equation of state w ( z ) of dark energy (DE) using a recently released data set containing 172 Type Ia supernovae (SNe) without assuming the prior w ( z ) ≥−1 (in contrast to previous studies). We find that DE evolves rapidly and metamorphoses from dust‐like behaviour at high z ( w ≃ 0 at z ∼ 1 ) to a strongly negative equation of state at present ( w ≲−1 at z ≃ 0 ). DE metamorphosis appears to be a robust phenomenon which manifests for a large variety of SNe data samples provided one does not invoke the weak energy prior ρ+ p ≥ 0 . Invoking this prior considerably weakens the rate of growth of w ( z ) . These results demonstrate that DE with an evolving equation of state provides a compelling alternative to a cosmological constant if data are analysed in a prior‐free manner and the weak energy condition is not imposed by hand.