[DSRP Evidence](https://dsrpevidence.org/)

# Weak evolution of cosmic atomic hydrogen over the past 4.5 billion years

Zhang et al., 2026, Nature Astronomy — Astronomy

Patterns: [Systems](https://dsrpevidence.org/pattern/systems), [Relationships](https://dsrpevidence.org/pattern/relationships)

## In short

A whole system's output (galaxy-wide star formation) is governed by an intervening relationship — the efficiency of converting one part (atomic gas) into the form actually usable (molecular gas) — rather than following directly from that part's abundance.

## What they found (results)

Analyzing about 2.5 million galaxies using FAST and DESI data, the team found star formation was roughly 2.5 times higher 4.5 billion years ago while atomic hydrogen reservoirs were only about 1.4 times larger, pointing to declining conversion efficiency from atomic to molecular hydrogen rather than a shrinking gas supply.

These researchers were not testing DSRP. The finding is theirs; the correspondence to DSRP is drawn by this site.

[Source](https://doi.org/10.1038/s41550-026-02965-9)