Classical spin in space with torsion and without torsion

Аuthors

Khrapko R. I.

e-mail: khrapko_ri@hotmail.com

Abstract

Operational definitions of energy-momentum and spin tensors and the equations connecting these tensors in a curved space and in a space with torsion are considered. According to the definitions, these tensors uniquely localize momentum and spin. By the definition of the spin tensor, as an example, absorption of spin of a circularly polarized electromagnetic wave is calculated for an electro-conducting medium. Such absorption results in an asymmetric energy-momentum tensor of the medium. The widespread objections against a reality of classical spin tensors are considered and rejected. A uselessness of the Belinfante symmetrization procedure is shown. The derivation of the metric energy-momentum tensors is criticized. Attention is directed to an analogy between the momentum and angular momentum conservation laws and the equations of motion of a dipole particle.

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