1210.6969 (Yannick Meurice et al.)

Fisher zeros and conformality in lattice models    [PDF]

Yannick Meurice, Alexei Bazavov, Bernd A. Berg, Daping Du, Alan Denbleyker, Yuzhi Liu, Donald K. Sinclair, Judah Unmuth-Yockey, Haiyuan Zou

Fisher zeros are the zeros of the partition function in the beta=2N_c/g^2 complex plane. When they pinch the real axis, finite size scaling allows to distinguish between first and second order transition and to estimate exponents. On the other hand, a gap signals confinement and the method can be used to explore the boundary of the conformal window. We present recent numerical results for 2D O(N) sigma models, 4D U(1) and SU(2) pure gauge and SU(3) with N_f=4and 12 flavors. We discuss attempts to understand some of these results using analytical methods. We discuss the 2-lattice matching and qualitative aspects of the renormalization group (RG) flows in the Migdal-Kadanoff approximation. We consider the effects of the boundary conditions on the nonperturbative part of the average energy in the 1D O(2) model

View original: http://arxiv.org/abs/1210.6969