Rate of early universe’s expansion slower than thought
DOI: 10.1063/PT.5.027824
BBC : The Baryon Oscillation Spectroscopic Survey has made the most precise measurement of the universe’s expansion to date. BOSS uses the regular, periodic ripples of visible baryonic matter that propagated from the early universe as a “standard ruler” to map the spatial distribution of quasars and luminous galaxies. The results show that the universe expanded rapidly right after the Big Bang, then within the first few billion years it slowed down, only to start speeding up again about 6 billion years ago. The new result is significant because of the deceleration, which is considerably slower than that predicted by the standard model of cosmology. If further measurements using bigger samples confirm those findings, it could mean that dark energy is not a manifestation of a cosmological constant.
