Tuesday, November 6, 2012

1211.0643 (A. M. Turner et al.)

Umbilical points of a non-Gaussian random field    [PDF]

A. M. Turner, T. H. Beuman, V. Vitelli
Random fields in nature often have, to a good approximation, Gaussian characteristics. For such fields, the relative densities of umbilical points -- topological defects which can be classified into three types -- have certain fixed values. Phenomena described by nonlinear laws can however give rise to a non-Gaussian contribution, causing a deviation from these universal values. We consider a Gaussian field with a perturbation added to it, given by a nonlinear function of that field, and calculate the change in the relative density of umbilical points. This allows us not only to detect a perturbation, but to determine its size as well. This geometric approach offers an independent way of detecting non-Gaussianity, which even works in cases where the field itself cannot be probed directly.
View original: http://arxiv.org/abs/1211.0643

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