BEGIN:VCALENDAR VERSION:2.0 PRODID:Data::ICal 0.22 BEGIN:VEVENT DESCRIPTION:Genya Kolomeisky\, University of Virginia\n\n
\n In 1952 Dyso n put forward a simple and powerful argument indicating that the perturbat ive expansions of QED are asymptotic. His argument can be related to Chand rasekhar'\;s limit on the mass of a star for stability against gravitat ional collapse. Combining these two arguments we estimate the optimal numb er of terms of the QED series to be approximately 5000. For condensed matt er manifestations of QED in narrow band-gap semiconductors and Weyl semime tals the optimal number of terms is around 80 while in graphene the utilit y of the perturbation theory is severely limited.
\n DTSTART:20141204T203000Z LOCATION:Physics Building\, Room 204 SUMMARY:Optimal number of terms in QED series and its consequence in conden sed matter implementations of QED END:VEVENT END:VCALENDAR