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Using cmb polarization to constrain the anomalous nature of the cold spot with an incomplete-sky coverage

Abstract: Recent results of the ESA Planck satellite have confirmed the existence of some anomalies in the statistical distribution of the cosmic microwave background (CMB) anisotropies. One of the most intriguing anomalies is the cold spot, first detected in the Wilkinson Microwave Anisotropy Probe (WMAP) data by Vielva et al. In a later paper, Vielva et al. (2011) developed a method to probe the anomalous nature of the cold spot by using the cross-correlation of temperature and polarization of the CMB fluctuations. Whereas this work was built under the assumption of analysing full-sky data, in this paper we extend such approach to deal with realistic data sets with a partial-sky coverage. In particular, we exploit the radial and tangential polarization patterns around temperature spots. We explore the capacity of the method to distinguish between a standard Gaussian CMB scenario and an alternative one, in which the cold spot arises from a physical process that does not present correlated polarization features (e.g. topological defects), as a function of the instrumental-noise level. Moreover, we consider more in detail the case of an ideal noise-free experiment and the ones with the expected instrumental-noise levels in QUIJOTE and Planck experiments. We also present an application to the 9-year WMAP data, without being able to obtain firm conclusions, with a significance level of 32 per cent. In the ideal case, the alternative scenario could be rejected at a significance level of around 1 per cent, whereas for expected noise levels of QUIJOTE and Planck experiments the corresponding significance levels are 1.5 and 7.4 per cent, respectively.

 Autoría: Fernández-Cobos R., Vielva P., Martínez-González E., Tucci M., Cruz M.,

 Fuente: Monthly Notices of the Royal Astronomical Society Volume 435, Issue 4, Pages 3096-3102

 Editorial: Oxford University Press

 Fecha de publicación: 01/09/2013

 Nº de páginas: 7

 Tipo de publicación: Artículo de Revista

 DOI: 10.1093/mnras/stt1505

 ISSN: 0035-8711,1365-2966

 Proyecto español: AYA2010-21766-C03-01 ; AYA2012-39475-C02-01

 Url de la publicación: https://doi.org/10.1093/mnras/stt1505