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Lanczos's equation as a way out of the spin 3/2 crisis?

Andre Gsponer·Jean-Pierre Hurni
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Abstract

It is shown (1) that Lanczos's quaternionic formulation of Dirac's equation does not lead to a solution of the problems that plague the standard spin 3/2 theory based on the Rarita-Schwinger equation, but (2) that the four-component solutions to the quaternionic generalization of Dirac's equation proposed by Lanczos in 1929 may provide a consistent theory for spin 3/2 particles, although at the cost of giving up the postulate that there should be a one-to-one correspondence between arbitrary-high-spin unitary representations of the inhomogeneous Lorentz group and elementary particles.

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Andre Gsponer, Jean-Pierre Hurni. 2003-01-06. Lanczos's equation as a way out of the spin 3/2 crisis?. https://arxiv.org/abs/math-ph/0210055

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