Four direct measurements of the fine-structure constant 13 billion years ago

• Published in: Science advances Vol. 6; no. 17
• Main Authors: Wilczynska, Michael R., Webb, John K., Bainbridge, Matthew, Barrow, John D., Bosman, Sarah E. I., Carswell, Robert F., Dąbrowski, Mariusz P., Dumont, Vincent, Lee, Chung-Chi, Leite, Ana Catarina, Leszczyńska, Katarzyna, Liske, Jochen, Marosek, Konrad, Martins, Carlos J. A. P., Milaković, Dinko, Molaro, Paolo, Pasquini, Luca
• Format: Journal Article
• Language: English
• Published: American Association for the Advancement of Science 24.04.2020
• Subjects: Astrophysics; SciAdv r-articles
• ISSN: 2375-2548
• DOI: 10.1126/sciadv.aay9672

Fine-structure constant measurements 13 Ga ago, plus lower redshift data, test space-time variation of a fundamental constant. Observations of the redshift z = 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 z = 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 0 ). The weighted mean electromagnetic force in this location in the universe deviates from the terrestrial value by Δα/α = (α z − α 0 )/α 0 = (−2:18 ± 7:27) × 10 −5 , 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.