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arXiv · 1103.4300

Can we detect Hot or Cold spots in the CMB with Minkowski Functionals?

Eugene A. Lim·Dennis Simon
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Abstract

In this paper, we investigate the utility of Minkowski Functionals as a probe of cold/hot disk-like structures in the CMB. In order to construct an accurate estimator, we resolve a long-standing issue with the use of Minkowski Functionals as probes of the CMB sky -- namely that of systematic differences ("residuals") when numerical and analytical MF are compared. We show that such residuals are in fact by-products of binning, and not caused by pixelation or masking as originally thought. We then derive a map-independent estimator that encodes the effects of binning, applicable to beyond our present work. Using this residual-free estimator, we show that small disk-like effects (as claimed by Vielva et al.) can be detected only when a large sample of such maps are averaged over. In other words, our estimator is noise-dominated for small disk sizes at WMAP resolution. To confirm our suspicion, we apply our estimator to the WMAP7 data to obtain a null result.

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Eugene A. Lim, Dennis Simon. 2011-03-22. Can we detect Hot or Cold spots in the CMB with Minkowski Functionals?. https://doi.org/10.1088/1475-7516%2F2012%2F01%2F048

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