2025-08-21 ミシガン大学
Left: A key figure from the report, exploring what the cosmologically coupled black holes, or CCBH, hypothesis implies about the mass of neutrinos, or “ghost particles.” Right: An annotation of this figure simplifying its main ideas. Image credit: Claire Lamman/DESI Collaboration
＜関連情報＞
- https://news.umich.edu/dark-energy-filled-black-holes-plus-desi-data-give-neutrino-masses-that-make-sense/
- https://journals.aps.org/prl/abstract/10.1103/yb2k-kn7h
物質変換による暗エネルギー経由でDESI DR2が観測した正ニュートリノ質量 Positive Neutrino Masses with DESI DR2 via Matter Conversion to Dark Energy
S. P. Ahlen, A. Aviles, B. Cartwright, K. S. Croker, W. Elbers, D. Farrah, N. Fernandez, G. Niz, J. W. Rohlf, et al. (DESI Collaboration)
Physical Review Letters Published: 21 August, 2025
DOI: https://doi.org/10.1103/yb2k-kn7h
Abstract
The Dark Energy Spectroscopic Instrument (DESI) is a massively parallel spectroscopic survey on the Mayall telescope at Kitt Peak, which has released measurements of baryon acoustic oscillations determined from over 14 million extragalactic targets. We combine DESI Data Release 2 with CMB datasets to search for evidence of matter conversion to dark energy (DE), focusing on a scenario mediated by stellar collapse to cosmologically coupled black holes (CCBHs). In this physical model, which has the same number of free parameters as ΛCDM, DE production is determined by the cosmic star formation rate density (SFRD), allowing for distinct early- and late-time cosmologies. Using two SFRDs to bracket current observations, we find that the CCBH model: accurately recovers the cosmological expansion history, agrees with early-time baryon abundance measured by BBN, reduces tension with the local distance ladder, and relaxes constraints on the summed neutrino mass ∑. For these SFRDs, we find a peaked positive ∑<0.149 eV (95% confidence) and ∑=0.106+0.050−0.069 eV, respectively, in good agreement with lower limits from neutrino oscillation experiments. A peak in ∑ >0 results from late-time baryon consumption in the CCBH scenario and is expected to be a general feature of any model that converts sufficient matter to dark energy during and after reionization.
