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http://dx.doi.org/10.4134/BKMS.b150355

HERMITIAN ALGEBRA ON GENERALIZED LEMNISCATES  

Putinar, Mihai (Department of Mathematics University of California at Santa Barbara, Newcastle University)
Publication Information
Bulletin of the Korean Mathematical Society / v.53, no.3, 2016 , pp. 821-831 More about this Journal
Abstract
A case study is added to our recent work on Quillen phenomenon. Pointwise positivity of polynomials on generalized lemniscates of the complex plane is related to sums of hermitian squares of rational functions, and via operator quantization, to essential subnormality.
Keywords
generalized lemniscate; positive polynomial; hermitian square; quadrature domain; subnormal operator;
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  • Reference
1 N. Feldman, Essentially subnormal operators, Proc. Amer. Math. Soc. 127 (1999), no. 4, 1171-1181.   DOI
2 B. Gustafsson and M. Putinar, Linear analysis of quadrature domains. II, Israel J. Math. 119 (2000), 187-216.   DOI
3 B. Gustafsson and H. S. Shapiro, What is a quadrature domain?, Quadrature domains and their applications, 1-25, Oper. Theory Adv. Appl. 156, Birkhauser, Basel, 2005.
4 D. Plaumann, Sums of squares on reducible real curves, Math. Z. 265 (2010), no. 4, 777-797.   DOI
5 A. Prestel and Ch. N. Delzell, Positive Polynomials, Springer Monographs in Mathematics. Springer-Verlag, Berlin, 2001.
6 M. Putinar, Notes on generalized lemniscates, Operator theory, systems theory and scattering theory: multidimensional generalizations, pp. 243-266, Oper. Theory Adv. Appl. 157, Birkhauser, Basel, 2005.
7 M. Putinar and C. Scheiderer, Hermitian algebra on the ellipse, Illinois J. Math. 56 (2012), no. 1, 213-220.
8 M. Putinar and C. Scheiderer, Quillen property of real algebraic varieties, Muenster J. Math., to appear.
9 D. G. Quillen, On the representation of hermitian forms as sums of squares, Invent. Math. 5 (1968), 237-242.   DOI
10 F. Riesz and B. Szokefalvi-Nagy, Functional Analysis, Dover Publ., New York, 1990.
11 C. Scheiderer, Sums of squares on real algebraic curves, Math. Z. 245 (2003), no. 4, 725-760.   DOI
12 C. Scheiderer, Positivity and sums of squares: A guide to recent results, In: Emerging Applications of Algebraic Geometry, pp. 271-324. IMA Vol. Math. Appl. 149, Springer, New York, 2009.