Four direct measurements of the fine-structure constant 13 billion years ago.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32917582.
- Also identified by DOI 10.1126/sciadv.aay9672 and PMC identifier 7182409.
- Licence recorded as CC BY-NC.
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Abstract
Observations of the redshift <i>z</i> = 7.085 quasar J1120+0641 are used to search for variations of the fine structure constant, α, over the redshift range 5.5 to 7.1. Observations at <i>z</i> = 7.1 probe the physics of the universe at only 0.8 billion years old. These are the most distant direct measurements of α to date and the first measurements using a near-IR spectrograph. A new AI analysis method is employed. Four measurements from the x-shooter spectrograph on the Very Large Telescope (VLT) constrain changes in a relative to the terrestrial value (α<sub>0</sub>). The weighted mean electromagnetic force in this location in the universe deviates from the terrestrial value by Δα/α = (α <i><sub>z</sub></i> - α<sub>0</sub>)/α<sub>0</sub> = (-2.18 ± 7.27) × 10<sup>-5</sup>, consistent with no temporal change. Combining these measurements with existing data, we find a spatial variation is preferred over a no-variation model at the 3.9σ level.