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Note on a product formula for unitary groups

Vincent Cachia
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Abstract

For any nonnegative self-adjoint operators A and B in a separable Hilbert space, we show that the Trotter-type formula $[(e^{i2tA/n}+e^{i2tB/n})/2]^n$ converges strongly in the closure of the intersection of the domains of A^{1/2} and B^{1/2}, along some subsequence and for almost every real number t. This result extends to the degenerate case and to Kato-functions following the method of Kato.

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Vincent Cachia. 2004-04-22. Note on a product formula for unitary groups. https://doi.org/10.1112/s0024609305004479

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