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Title: 21-cm Radiation: A New Probe of Variation in the Fine-Structure Constant

Abstract

We investigate the effect of variation in the value of the fine-structure constant ({alpha}) at high redshifts (recombination >z>30) on the absorption of the cosmic microwave background (CMB) at 21 cm hyperfine transition of the neutral atomic hydrogen. We find that the 21 cm signal is very sensitive to the variations in {alpha} and it is so far the only probe of the fine-structure constant in this redshift range. A change in the value of {alpha} by 1% changes the mean brightness temperature decrement of the CMB due to 21 cm absorption by >5% over the redshift range z<50. There is an effect of similar magnitude on the amplitude of the fluctuations in the brightness temperature. The redshift of maximum absorption also changes by {approx}5%.

Authors:
;  [1];  [2]
  1. Department of Astronomy, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, Illinois 61801 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
20957743
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 98; Journal Issue: 11; Other Information: DOI: 10.1103/PhysRevLett.98.111301; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION; BRIGHTNESS; FINE STRUCTURE; HYDROGEN; RECOMBINATION; RELICT RADIATION; SIGNALS

Citation Formats

Khatri, Rishi, Wandelt, Benjamin D., and Departments of Physics and Astronomy, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, Illinois 61801. 21-cm Radiation: A New Probe of Variation in the Fine-Structure Constant. United States: N. p., 2007. Web. doi:10.1103/PHYSREVLETT.98.111301.
Khatri, Rishi, Wandelt, Benjamin D., & Departments of Physics and Astronomy, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, Illinois 61801. 21-cm Radiation: A New Probe of Variation in the Fine-Structure Constant. United States. doi:10.1103/PHYSREVLETT.98.111301.
Khatri, Rishi, Wandelt, Benjamin D., and Departments of Physics and Astronomy, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, Illinois 61801. Fri . "21-cm Radiation: A New Probe of Variation in the Fine-Structure Constant". United States. doi:10.1103/PHYSREVLETT.98.111301.
@article{osti_20957743,
title = {21-cm Radiation: A New Probe of Variation in the Fine-Structure Constant},
author = {Khatri, Rishi and Wandelt, Benjamin D. and Departments of Physics and Astronomy, University of Illinois at Urbana-Champaign, 1002 West Green Street, Urbana, Illinois 61801},
abstractNote = {We investigate the effect of variation in the value of the fine-structure constant ({alpha}) at high redshifts (recombination >z>30) on the absorption of the cosmic microwave background (CMB) at 21 cm hyperfine transition of the neutral atomic hydrogen. We find that the 21 cm signal is very sensitive to the variations in {alpha} and it is so far the only probe of the fine-structure constant in this redshift range. A change in the value of {alpha} by 1% changes the mean brightness temperature decrement of the CMB due to 21 cm absorption by >5% over the redshift range z<50. There is an effect of similar magnitude on the amplitude of the fluctuations in the brightness temperature. The redshift of maximum absorption also changes by {approx}5%.},
doi = {10.1103/PHYSREVLETT.98.111301},
journal = {Physical Review Letters},
number = 11,
volume = 98,
place = {United States},
year = {Fri Mar 16 00:00:00 EDT 2007},
month = {Fri Mar 16 00:00:00 EDT 2007}
}