2010/12/14 by Puxun Wu, Hongwei Yu, Wu, Puxun +1
Earth and Planetary Sciences · Physics and Astronomy · #Acceleration #Astronomy #Astronomy and Astrophysical Research #Astrophysics #COSMIC cancer database #Classical mechanics #Cosmology #Cosmology and Gravitation Theories #Dark energy #Deceleration parameter #Galaxy #Geophysics and Gravity Measurements #Metric expansion of space #Physical cosmology #Physics #Redshift #astro-ph.CO
paper · pdf · doi:10.48550/arxiv.1012.3032
8 pages, 2 figures
arxiv created 2010/12/14 · openalex publication_date 2010/12/14 · arxiv updated 2010/12/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We probe the recent cosmic expansion by directly reconstructing the deceleration parameter q(z) at recent times with a linear expansion at z=0 using the low redshift SNIa and BAO data. Our results show that the observations seem to favor a slowing down of the present cosmic acceleration. Using only very low redshift SNIa data, for example, those within z<0.1 or 0.2, we find that our Universe may have already entered a decelerating expansion era since a positive q(0) seems to be favored. This result is further supported by a different approach which aims to reconstruct q(z) in the whole redshift region. So, the accelerating cosmic expansion may be just a transient phenomenon.