Phys. Rev. Lett. 85, 5511–5514 (2000)Astronomical Constraints on the Cosmic Evolution of the Fine Structure Constant and Possible Quantum DimensionsSee Also: Erratum
We present measurements of absorption by the 21 cm hyperfine transition of neutral hydrogen toward radio sources at substantial look-back times. These data are used in combination with observations of rotational transitions of common interstellar molecules to set limits on the evolution of the fine structure constant: α̇/α<3.5×10-15yr-1, to a look-back time of 4.8 Gyr. In the context of string theory, the limit on the secular evolution of the scale factor of the compact dimensions, R, is Ṙ/R<10-15yr-1. Including terrestrial and other astronomical measurements places 2σ limits on slow oscillations of R from the present to the epoch of cosmic nucleosynthesis, just seconds after the big bang, of ΔR/R<10-5. © 2000 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevLett.85.5511
DOI:
10.1103/PhysRevLett.85.5511
PACS:
98.80.Es, 06.20.Jr
See AlsoErratum: C. L. Carilli, K. M. Menten, J. T. Stocke, E. Perlman, R. Vermeulen, F. Briggs, A. G. de Bruyn, J. Conway, and C. P. Moore, Erratum: Astronomical Constraints on the Cosmic Evolution of the Fine Structure Constant and Possible Quantum Dimensions [Phys. Rev. Lett. 85, 5511 (2000)], Phys. Rev. Lett. 86, 1910 (2001). |
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