Entropy constraints on effective field theory

Lectures on Effective Field Theory

On Thermal Entropy in Quantum Field Theory

Standard entropy calculations in quantum field theory, when applied to a subsystem of definite volume, exhibit area-dependent UV divergences that make a thermodynamic interpretation troublesome. Such divergences cannot be reabsorbed by local counterterms although, with a rather unusual procedure, they can be subtracted from the final result. A key issue here is which set of quantum degrees of f...

Effective Field Theory

Attempts to apply effective field theory (EFT) methods to nonrelativistic nucleon-nucleon (N N) scattering have raised questions about the nature and limitations of an EFT expansion when used nonperturbatively. We discuss the characteristics of a meaningful EFT analysis and compare them with traditional approaches to N N scattering. A key feature of an EFT treatment is a systematic expansion in...

On String Field Theory and Effective Actions

A truncation of string field theory is compared with the duality invariant effective action of D = 4, N = 4 heterotic strings to cubic order. The three string vertex must satisfy a set of compatibility conditions. Any cyclic three string vertex is compatible with the D = 4, N = 4 effective field theory. The effective actions may be useful in understanding the non–polynomial structure and the un...

Effective Field Theory ∗ † ‡

3 " Integrating Out " versus " Matching " 19 3.