23 research outputs found
Entropic C-theorems in free and interacting two-dimensional field theories
The relative entropy in two-dimensional field theory is studied on a cylinder
geometry, interpreted as finite-temperature field theory. The width of the
cylinder provides an infrared scale that allows us to define a dimensionless
relative entropy analogous to Zamolodchikov's function. The one-dimensional
quantum thermodynamic entropy gives rise to another monotonic dimensionless
quantity. I illustrate these monotonicity theorems with examples ranging from
free field theories to interacting models soluble with the thermodynamic Bethe
ansatz. Both dimensionless entropies are explicitly shown to be monotonic in
the examples that we analyze.Comment: 34 pages, 3 figures (8 EPS files), Latex2e file, continuation of
hep-th/9710241; rigorous analysis of sufficient conditions for universality
of the dimensionless relative entropy, more detailed discussion of the
relation with Zamolodchikov's theorem, references added; to appear in Phys.
Rev.