DIMENSIONAL REDUCTION AND QUANTUM-TO-CLASSICAL REDUCTION AT HIGH-TEMPERATURES

We discuss the relation between dimensional reduction in quantum held theories at finite temperature and a familiar quantum-mechanical pheno menon that quantum effects become negligible at high temperatures. Fer mi and Bose fields are compared in this respect. We show that decoupli ng of fermions from the dimensionally reduced theory can be related to the nonexistence of classical statistics for a Fermi field.