Leverage toward an OPEN universe

Upon poring over recent data input on the universe, a team of scientists considers means by which an OPEN universe could be construed and may further be augmented. An Open universe would never close and provide endless expansion by measurements used to determine curvature.

The team is Deng Wang, Olga Mena, Salvatore Caposzziello and David Mota. Their work can be seen at arxiv.org, 2512.19565.

They note, "That detection of a significant deviation from a zero curvature would have profound consequences for inflationary theories and fundamental physics."

The low redshift universe observations favor an open universe, and this preference persists even when alternative high-redshift priors are adopted. 

"This does not mean that cosmic curvature can definitely help in resolving these issues but it plays a crucial role in describing the composition, evolution and fate of the universe."

It is a fact that the universe is described as flat. That implies zero curvature. but attention should be paid to its details. "Curvature depicting the geometry of the universe influences significantly the manifestation of various cosmic tension and problems."

Recent releases of DESI DR2 BAO provide a constraint on curvature at 0.025, "being consistent  with zero curvature at the 1 sigma level." "which is clearly inconsistent with Planck"s predictions." Planck was measuring the features of the early universe. But some of those measurements don't match with data of more recent times. Question is: "Is there a curvature tension between the early universe and the late universe observations?"

The findings, in their detailed analysis, "shows the fact that low-redshift data clearly prefers an open universe. That is the case for DESI, Pantheon+, Union3 and DESY5 data. On the other hand, Planck, and CMB observations prefer a closed unverse with Omega k less than zero."

"This statement is true as long as DESI data are not considered with the data analyses.  When these observations are combined with the CMB ones, the preference for a negative curvature disappears and changes to a preference for a positive one"

i.e. Open universe.