On the kinematics of the last Wigner particle

Wigner’s particle classification provides for “continuous spin” representations of the Poincar'e group, corresponding to a class of (as yet unobserved) massless particles. Rather than building their induced realizations by use of “Wigner rotations” in the textbooks’ way, here we exhibit a scalar-like first-quantized form of those (bosonic) Wigner particles directly, by combining wave equations proposed by Wigner long ago with a recent prequantized treatment employing Poisson structures.