In February I gave a talk with the title “When effective field theory fail”

as the opening talk to a conference on effective field theory in Valencia in February. The paper has now been posted and will be published in the proceedings of the conference.

The title was somewhat provocative, and in some ways the whole talk was also. One of the things that interests me is the limits of effective field theory. The talk describes four cases in which I think that the effective theory fails in ways that are not expected by conventional practice. The most detailed is a study of kaon loops in chiral perturbation theory, which I have come to realize are not reliable. The Regge physics of my paper with Daniel Wyler is a second example. I have long had some concerns about the extremely long distance behavior of gravity – these are phrased more clearly in this paper. Finally, there is a paper (likely two) with Mohamed Anber and Ufuk Aydemir that is foreshadowed in the talk – hopefully this paper should appear soon.