Decoherence in quantum Kaluza-Klein theories

Kaluza-Klein theories permit a variety of compactifications and arbitrary scales for the internal space. There must be no quantum interference between these different possibilities. This paper demonstrates that in the Salam-Sezgin compactification interference between differently scaled internal spaces is suppressed. The calculation is carried out in the WKB approximation, and all questions of non-renormalizability are neglected. (orig.)