Illinois Journal of Mathematics

Hermitian algebra on the ellipse

Mihai Putinar and Claus Scheiderer

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The subtle distinction between hermitian sums of squares and sums of squares, regarded as positivity certificates of a polynomial restricted to a real algebraic variety, is analyzed on the simplest, yet very relevant, example: an ellipse.

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Illinois J. Math., Volume 56, Number 1 (2012), 213-220.

First available in Project Euclid: 27 September 2013

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Primary: 12D15: Fields related with sums of squares (formally real fields, Pythagorean fields, etc.) [See also 11Exx]
Secondary: 14P05: Real algebraic sets [See also 12D15, 13J30] 15B57: Hermitian, skew-Hermitian, and related matrices 32V15: CR manifolds as boundaries of domains


Putinar, Mihai; Scheiderer, Claus. Hermitian algebra on the ellipse. Illinois J. Math. 56 (2012), no. 1, 213--220. doi:10.1215/ijm/1380287468.

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