Stefan Machlup

Stefan Machlup was an American physicist who, with the Nobel laureate Lars Onsager, published in 1952 the influential papers introducing what became the Onsager-Machlup function, describing fluctuations and the probability of paths in thermodynamic systems. He spent some 45 years on the physics faculty of Western Reserve and later Case Western Reserve University. From a Viennese Jewish family that left Austria, he is listed among Jewish figures in Jewish biographical compilations; mainstream biographies give few details of his religious background.