Requardt M.
A New Class of Bounds for Correlation Functions in Euclidean Lattice
Field Theory and Statistical Mechanics of Spin Systems
(21K, Latex)
ABSTRACT. Starting from an extension of the Poisson bracket structure and
Kubo-Martin-Schwinger-property of classical statistical mechanics of
continuous systems to spin systems, defined on a lattice, we derive a
series of, as we think, new and interesting bounds on correlation
functions for general lattice systems. Our method is expected to
yield also useful results in Euclidean Field Theory. Furthermore the
approach is applicable in situations where other techniques fail,
e.g. in the study of phase transitions without breaking of a {\bf
continuous} symmetry like $P(\phi)$-theories with $\phi (x)$ scalar.