Methods for Constraining Fine Structure Constant Evolution with OH Microwave Transitions

2003/05/29 by Jeremy Darling · 5 citations
Physics and Astronomy · #Anisotropy #Astrophysics #Astrophysics and Cosmic Phenomena #Atomic physics #Computational physics #Constant (computer programming) #Cosmic microwave background #Fine-structure constant #Galaxies: Formation, Evolution, Phenomena #Geometry #Hyperfine structure #Lambda #Line (geometry) #Maser #Microwave #Millimeter #Physics #Planck #Quantum mechanics #Radio Astronomy Observations and Technology #Statistics #Systematic error #astro-ph

paper · pdf · doi:10.1103/physrevlett.91.011301

published as Phys.Rev.Lett. 91 (2003) 011301 · RevTeX, 4 pages, 1 figure, accepted by Physical Review Letters

arxiv created 2003/05/29 · openalex publication_date 2003/07/03 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We investigate the constraints that OH microwave transitions in megamasers and molecular absorbers at cosmological distances may place on the evolution of the fine structure constant alpha=e(2)/ variant Planck's over 2pi c. The centimeter OH transitions are a combination of hyperfine splitting and lambda doubling that can constrain the cosmic evolution of alpha from a single species, avoiding systematic errors in alpha measurements from multiple species which may have relative velocity offsets. The most promising method compares the 18 and 6 cm OH lines, includes a calibration of systematic errors, and offers multiple determinations of alpha in a single object. Comparisons of OH lines to the HI 21 cm line and CO rotational transitions also show promise.

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