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Perspectives on Nonlinearity in Quantum Theory

Gerald A. Goldin
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Abstract

An enlarged group G of nonlinear transformations, modeled on the general linear group GL(2,R), leads to a beautiful, apparently unremarked symmetry between the wave function's phase and the logarithm of its amplitude. Equations Doebner and I earlier proposed are embedded in a wider, natural family of nonlinear time-evolution equations, on which G acts as a gauge group (leaving physical observations invariant). There exist G-invariant quantities that reduce to the usual probability density and flux for linearizable quantum theories in a particular gauge.

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Gerald A. Goldin. 2000-02-02. Perspectives on Nonlinearity in Quantum Theory. https://arxiv.org/abs/quant-ph/0002013

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