Status  Confirmed 
Seminar Series  STRINT 
Subjects  hepth 
Date  Thursday 7 December 2017 
Time  14:30 
Institute  LPTENS 
Seminar Room  LPTENS Library 
Speaker's Last Name  Ravanini 
Speaker's First Name  Francesco 
Speaker's Email Address  
Speaker's Institution  Bologna University 
Title  The c_eff theorem: Irreversibility of RG Flows in 2D Nonunitary QFT’s 
Abstract  Abstract: We show irreversibility of the renormalization group flow in non unitary but PT invariant quantum field theory in two spacetime dimensions. In addition to unbroken PTsymmetry and a positive energy spectrum, we assume standard properties of quantum field theory including a local energymomentum tensor and relativistic invariance. This generalizes Zamolodchikov's ctheorem to PT symmetric hamiltonians. Our proof follows closely Zamolodchikov's arguments. We show that a function c_eff (s) of the renormalization group parameter s exists which is nonnegative and monotonically decreasing along renormalization group flows. Its value at a critical point is the "effective central charge" entering the specific free energy. At least in rational models, this equals c_eff =c24 Delta, where c is the central charge and Delta is the lowest primary field dimension in the conformal field theory which describes the critical point. 
arXiv Preprint Number  
Comments  
Attachments 
To Generate a poster for this seminar : [ Postscript  PDF ]

[ English version ] 