Partition function based analysis of cosmic microwave background maps

Citation
Jm. Diego et al., Partition function based analysis of cosmic microwave background maps, M NOT R AST, 306(2), 1999, pp. 427-436
Citations number
47
Categorie Soggetti
Space Sciences
Journal title
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
ISSN journal
00358711 → ACNP
Volume
306
Issue
2
Year of publication
1999
Pages
427 - 436
Database
ISI
SICI code
0035-8711(19990621)306:2<427:PFBAOC>2.0.ZU;2-J
Abstract
We present an alternative method to analyse cosmic microwave background (CM B) maps. We base our analysis on the study of the partition function. This function is used to examine the CMB maps, making use of the different infor mation embedded at different scales and moments. Using the partition function in a likelihood analysis in two dimensions (Q( rms)-(PS),n) We find the best-fitting model to the best data available at p resent (the COBE-DMR 4 years data set). By means of this analysis we find a maximum in the likelihood function for n = 1.8(-0.65)(+0.35) and Q(rms-PS) = 10(-2.5)(+3) mu K (95 per cent confidence level) in agreement with the r esults of other similar analyses [Smoot et al, (1 yr), Bennet et al. (4 yr) ]. Also making use of the partition function we perform a multifractal analysi s and study the possible fractal nature of the CMB sky. We find that the me asure used in the analysis is not a fractal. Finally, we use the partition function for testing the statistical distribution of the COBE-DMR data set. We conclude that no evidence of non-Gaussianity can be found by means of t his method.