We describe the geometric structure of the ${\Cal L}$-characteristic of fractional powers of bounded or compact linear operators over domains with arbitrary measure. The description builds essentially on the Riesz-Thorin and Marcinkiewicz-Stein-Weiss-\linebreak Ovchinnikov interpolation theorems, as well as on the Krasnosel'skij-Krejn factorization theorem.
@article{118637, author = {J\"urgen Appell and Marilda A. Sim\~oes and Petr P. Zabrejko}, title = {On the $\Cal L$-characteristic of fractional powers of linear operators}, journal = {Commentationes Mathematicae Universitatis Carolinae}, volume = {35}, year = {1994}, pages = {21-34}, zbl = {0806.47014}, mrnumber = {1292579}, language = {en}, url = {http://dml.mathdoc.fr/item/118637} }
Appell, Jürgen; Simões, Marilda A.; Zabrejko, Petr P. On the $\Cal L$-characteristic of fractional powers of linear operators. Commentationes Mathematicae Universitatis Carolinae, Tome 35 (1994) pp. 21-34. http://gdmltest.u-ga.fr/item/118637/
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