Abstract
Let Uscript K(t) be a one-parameter operator family of positive type in a Hilbert space script K and U(t) its minimal unitary dilation with infinitesimal generator H. If Uscript K(t) is a contractive semigroup, then H is not positive. If in addition Uscript K(t)→0 for t→∞, then there exists a state φ ∈ script K on which H is not defined. We interpret these and other results in the context of the quantum-mechanical theory of unstable particles and the scattering theory of Lax and Phillips.
Original language | English |
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Pages (from-to) | 2537-2543 |
Number of pages | 7 |
Journal | Journal of Mathematical Physics |
Volume | 12 |
Issue number | 12 |
DOIs | |
State | Published - 1971 |
Externally published | Yes |