WMAP constraints on varying alpha and the promise of reionization

• Type: Article in International Scientific Journal
• Date: 2004

Authors

martins, cjap (Author) Other; melchiorri, a (Author) Other; rocha, g (Author) Other; trotta, r (Author) Other; avelino, pp (Author) FCUP; viana, ptp (Author) FCUP

Journal

Title: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics

Vol. 585

Pages: 29-34

ISSN: 0370-2693

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 65 Citations

Scopus - 64 Citations

Scientific classification

FOS: Natural sciences > Physical sciences

Other information

Authenticus ID: P-000-AV5

DOI: 10.1016/j.physletb.2003.11.080

Abstract (EN): We present up-to-date constraints on the value of the fine-structure constant at the epoch of decoupling from the recent observations made by the Wilkinson Microwave Anisotropy Probe (WMAP) satellite. In the framework of models we considered, a positive (negative) variation of the value of alpha at decoupling with respect to the present-day value is now bounded to be smaller than 2% (6%) at 95% confidence level. We point out that the existence of an early reionization epoch as suggested by the above measurements will, when more accurate cosmic microwave background polarization data is available, lead to considerably tighter constraints. The so-called 'reionization bump', in particular, will be extremely useful for this purpose. We find that the tightest possible constraint on alpha is about 0.1% using CMB data alone-tighter constraints will require further (non-CMB) priors.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6