Abstract. It is demonstrated that stochastic c-number theories fail as a model of weak measurements on thermal radiation of low occupation numbers. This occurs, for example, at the wavelength of maximum irradiation in blackbody radiation. The classical model is approximately capable of describing weak measurements at high occupation numbers. The nonclassical effect is only present for quantum states with a negative Terletsky–Margenau–Hill quasi-probability distribution.

Keywords: nonclassicality, thermal radiation, blackbody radiation, chaotic states, weak values, weak measurements, P-distribution, Margenau–Hill distribution, Kirkwood distribution

Print publication: Issue 12 (December 2004)
Received 21 June 2004, accepted for publication 23 September 2004
Published 15 October 2004