In this work we study the essential sets for some Kato measure in . Using the caracterisation of Picard principle via the Green kernel associated to the Schrödinger operator ; we give a new caracterisation of such sets when where is assumed to be rotation free nonnegative, decreasing and locally Hölder continuous on . In particular we obtain results given by T. Tada in the case where and .
"Caractérisation des ensembles essentiels." J. Math. Soc. Japan 54 (2) 467 - 486, April, 2002. https://doi.org/10.2969/jmsj/05420467