Generalized emissivity inverse problem.

Inverse problems have recently drawn considerable attention from the physics community due to of potential widespread applications [K. Chadan and P. C.

Functional integral approach: a third formulation of quantum statistical mechanics.

Quantum statistical mechanics has developed primarily through two approaches, pioneered by Gibbs and Feynman, respectively. In Gibbs' method one calculates partition functions from phase-space integrations or sums over stationary states. Alternatively, in Feynman's approach, the focus is on the path-integral formulation.