Is cosmic acceleration slowing down

By A. Shafieloo, V. Sahni, A. Starobinsky. 2009

197 citations recorded by the source corpus.

We investigate the course of cosmic expansion in its recent past using the Constitution SN Ia sample, along with baryon acoustic oscillations (BAO) and cosmic microwave background (CMB) data. Allowing the equation of state of dark energy (DE) to vary, we find that a coasting model of the universe (q{sub 0}=0) fits the data about as well as Lambda cold dark matter. This effect, which is most clearly seen using the recently introduced Om diagnostic, corresponds to an increase of Om and q at redshifts z < or approx. 0.3. This suggests that cosmic acceleration may have already peaked and that we are currently witnessing its slowing down. The case for evolving DE strengthens if a subsample of the Constitution set consisting of SNLS+ESSENCE+CfA SN Ia data is analyzed in combination with BAO+CMB data. The effect we observe could correspond to DE decaying into dark matter (or something else)

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/553eb3a7e645a6a55888b97ed2417c8489ee023f

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Citations in the corpus

DESI 2024: reconstructing dark energy using crossing statistics with DESI DR1 BAO data (2024, background): “4 lower two panels), opens the door to models with a slowing down of cosmic acceleration [107].”
A Simple Phenomenological Emergent Dark Energy Model can Resolve the Hubble Tension (2019, background): “…at the latest stages of this work, we became aware of the work of Keeley et al. (2019), which discussed a similar behavior of dark energy, but employed a parametric form that has few degrees of freedom similar to what has been introduced earlier in Bassett et al. (2002); Shafieloo et al. (2009).”