Seminari del Dipartimento


Fisica Matematica

Supersymmetry and Ward identities as a tool to study functional integrals

Margherita Disertori

08-05-2018 - 14:30
Largo San Leonardo Murialdo,1 - Pal.C - AULA 311


In the context of field theory Ward identities are functional identites generated by internal symmmetries of the model. They generally appear as relations between Feynman diagrams, allowing to simplify the perturbative expansion, and in some cases even to close the Schwinger-Dyson equation. A natural question is whether symmetry-generated identities may also help to study models where standard renormalization group techniques do not apply. In this context, in collaboration with M. Zirnbauer and T. Spencer, we considered a  nonlinear sigma model, which is the key ingredient in the construction and study of certain stochastic processes with memory. The corresponding integral is invariant under supersymmetric transformations that  generate an infinite family of Ward identities.
Though these identities have no interpretation as Feynman diagrams, they proved to be a key ingredient in the analysis of the model.
org: GIULIANI Alessandro


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