The Fine Structure Constant and the CMB Damping Scale

Дата и время публикации : 2012-02-07T17:46:25Z

Авторы публикации и институты :
Eloisa Menegoni
Maria Archidiacono
Erminia Calabrese
Silvia Galli
C. J. A. P. Martins
Alessandro Melchiorri

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 4 pages, 1 figure
Первичная категория: astro-ph.CO

Все категории : astro-ph.CO

Краткий обзор статьи: The recent measurements of the Cosmic Microwave Background anisotropies at arcminute angular scales performed by the ACT and SPT experiments are probing the damping regime of CMB fluctuations. The analysis of these datasets unexpectedly suggests that the effective number of relativistic degrees of freedom is larger than the standard value of Neff = 3.04, and inconsistent with it at more than two standard deviations. In this paper we study the role of a mechanism that could affect the shape of the CMB angular fluctuations at those scales, namely a change in the recombination process through variations in the fine structure constant. We show that the new CMB data significantly improve the previous constraints on variations of {alpha}, with {alpha}/{alpha}0 = 0.984 pm 0.005, i.e. hinting also to a more than two standard deviation from the current, local, value {alpha}0. A significant degeneracy is present between {alpha} and Neff, and when variations in the latter are allowed the constraints on {alpha} are relaxed and again consistent with the standard value. Deviations of either parameter from their standard values would imply the presence of new, currently unknown physics.

Category: Physics