Extensions of dissipative operators with closable imaginary part

Given a dissipative operator A on a complex Hilbert space H such that the quadratic form ƒ → Im( ƒ A&fnof] is closable, we give a necessary and sufficient condition for an extension of A to still be dissipative. As applications, we describe all maximally accretive extensions of strictly positive symmetric operators and all maximally dissipative extensions of a highly singular first-order operator on the interval.

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Opracowanie rekordu ze środków MNiSW, umowa Nr 461252 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2021).