University of Minnesota
School of Physics & Astronomy

Physics and Astronomy Calendar

Wednesday, October 7th 2015
1:25 pm:
Speaker: Eugene Kolomeisky - University of Virginia
Subject: Optimal number of terms in QED series and its consequence in condensed matter implementations of QED

In 1952 Dyson put forward a simple and powerful argument indicating that the perturbative expansions of QED are asymptotic. His argument can be related to Chandrasekhar's limit on the mass of a star for stability against gravitational collapse. Combining these two arguments we estimate the optimal number of terms of the QED series to be 3.1(137)^{3/2}\approx5000 . For condensed matter manifestations of QED in narrow band-gap semiconductors and Weyl semimetals the optimal number of terms is around 80 while in graphene the utility of the perturbation theory is severely limited.

Faculty Host: Boris Shklovskii

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