ua nt - p h / 01 11 06 0 v 1 9 N ov 2 00 1 Localization and causality for a free particle
نویسندگان
چکیده
Theorems (most notably by Hegerfeldt) prove that an initially localized particle whose time evolution is determined by a positive Hamiltonian will violate causality. We argue that this apparent paradox is resolved for a free particle described by either the Dirac equation or the Klein-Gordon equation because such a particle cannot be localized in the sense required by the theorems.
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