The Daugavet equation for polynomials
Yun Sung Choi ; Domingo García ; Manuel Maestre ; Miguel Martín
Studia Mathematica, Tome 178 (2007), p. 63-84 / Harvested from The Polish Digital Mathematics Library

We study when the Daugavet equation is satisfied for weakly compact polynomials on a Banach space X, i.e. when the equality ||Id + P|| = 1 + ||P|| is satisfied for all weakly compact polynomials P: X → X. We show that this is the case when X = C(K), the real or complex space of continuous functions on a compact space K without isolated points. We also study the alternative Daugavet equation max|ω|=1||Id+ωP||=1+||P|| for polynomials P: X → X. We show that this equation holds for every polynomial on the complex space X = C(K) (K arbitrary) with values in X. This result is not true in the real case. Finally, we study the Daugavet and the alternative Daugavet equations for k-homogeneous polynomials.

Publié le : 2007-01-01
EUDML-ID : urn:eudml:doc:285199
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     title = {The Daugavet equation for polynomials},
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Yun Sung Choi; Domingo García; Manuel Maestre; Miguel Martín. The Daugavet equation for polynomials. Studia Mathematica, Tome 178 (2007) pp. 63-84. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm178-1-4/