68 research outputs found
On a Full Quantization of the Torus
I exhibit a prequantization of the torus which is actually a ``full''
quantization in the sense that a certain complete set of classical observables
is irreducibly represented. Thus in this instance there is no Groenewold-Van
Hove obstruction to quantization.Comment: 8 pages, AMS-LaTe
Stress-Energy-Momentum Tensors and the Belinfante-Rosenfeld Formula
We present a new method of constructing a stress-energy-momentum tensor
for a classical field theory based on covariance considerations and Noether theory.
The stress-energy-momentum tensor T ^Ī¼
_Ī½ that we construct is defined using
the (multi)momentum map associated to the spacetime diffeomorphism group.
The tensor T ^Ī¼
_Ī½ is uniquely determined as well as gauge-covariant, and depends
only upon the divergence equivalence class of the Lagrangian. It satisfies
a generalized version of the classical Belinfante-Rosenfeld formula, and hence
naturally incorporates both the canonical stress-energy-momentum tensor and
the ācorrection termsā that are necessary to make the latter well behaved. Furthermore,
in the presence of a metric on spacetime, our T^(Ī¼Ī½) coincides with the
Hilbert tensor and hence is automatically symmetric
A Groenewold-Van Hove Theorem for S^2
We prove that there does not exist a nontrivial quantization of the Poisson
algebra of the symplectic manifold S^2 which is irreducible on the subalgebra
generated by the components {S_1,S_2,S_3} of the spin vector. We also show that
there does not exist such a quantization of the Poisson subalgebra P consisting
of polynomials in {S_1,S_2,S_3}. Furthermore, we show that the maximal Poisson
subalgebra of P containing {1,S_1,S_2,S_3} that can be so quantized is just
that generated by {1,S_1,S_2,S_3}.Comment: 20 pages, AMSLaTe
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