This document may be downloaded, read, stored and printed for your own use within the limits of § 53 UrhG but it may not be distributed via the internet or passed on to external parties.Dieses Dokument darf im Rahmen von § 53 UrhG zum eigenen Gebrauch kostenfrei heruntergeladen, gelesen, gespeichert und ausgedruckt, aber nicht im Internet bereitgestellt oder an Außenstehende weitergegeben werden.Exner, PavelNeidhardt, Hagen2016-03-242019-06-2820090946-8633https://doi.org/10.34657/3434https://oa.tib.eu/renate/handle/123456789/2128Let $A$ and $B$ be non-negative self-adjoint operators in a separable Hilbert space such that its form sum $C$ is densely defined. It is shown that the Trotter product formula holds for imaginary times in the $L^2$-norm. The result remains true for the Trotter-Kato product formula for so-called holomorphic Kato functions; we also derive a canonical representation for any function of this class.application/pdfeng510Trotter product formulaTrotter-Kato product formulaunitary groupsFeynman path integralsholomorphic Kato functions.Report