Paper
Positivity with Long-Range Interactions
Authors
B. Bellazzini, J. Berman, G. Isabella, F. Riva, M. Romano, F. Sciotti
Abstract
We introduce infrared finite, analytic, crossing symmetric, Regge behaved, and Lorentz invariant amplitudes , labeled by the experimental energy resolution for detecting soft photons and gravitons. For exponentially smaller than any hard scale, they also satisfy unitarity and their associated cross sections reproduce the inclusive, infrared-finite cross sections of ordinary amplitudes. These properties make suitable for deriving infrared-safe positivity bounds on effective field theories in the presence of long-range forces even in . As an illustration, we present explicit bounds in the low-energy theory of pions coupled to electromagnetism and gravity.