Numerical Range and Quasi - Sectorial Contractions
نویسنده
چکیده
We apply a method developed by one of the authors, see [1], to localize the numerical range of quasi-sectorial contractions semigroups. Our main theorem establishes a relation between the numerical range of quasi-sectorial contraction semigroups {exp(−tS)}t≥0, and the maximal sectorial generators S. We also give a new prove of the rate O(1/n) for the operator-norm Euler formula approximation: exp(−tS) = lim n→∞ (I + tS/n), t ≥ 0, for this class of semigroups.
منابع مشابه
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