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Journal of Physics C Solid State Physics

On the response of arbitrary finite order and its relation to imaginary-time correlation functions

R. P. Wehrum, H Hermeking

Published Mar 21, 1974• 9 citations
Publisher

Abstract

The Nth-order response, effected by an external scalar field coupled to a system initially in thermodynamic equilibrium, is expressed with the help of imaginary-time correlation function using the spectral representation of its Fourier coefficients.
DOI
10.1088/0022-3719/7/6/003

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