Critical behavior of Gaussian model on diamond-type hierarchical lattices

1999 ◽  
Vol 42 (3) ◽  
pp. 325-331 ◽  
Author(s):  
Kong Xiangmu ◽  
Li Song
1988 ◽  
Vol 38 (1) ◽  
pp. 728-731 ◽  
Author(s):  
Z. R. Yang

1995 ◽  
Vol 10 (35) ◽  
pp. 2709-2725
Author(s):  
E. VINTELER

The star-matrix models are difficult to solve due to the multiple powers of the Vandermonde determinants in the partition function. We apply to these models a modified Q-matrix aprpoach and we get results consistent with those obtained by other methods. As examples we study the inhomogeneous Gaussian model on Bethe tree and matrix q-Potts-like model. For the last model in the special cases q=2 and q=3, we write down explicit formulas which determine the critical behavior of the system. For q=2 we argue that the critical behavior is indeed that of the Ising model on the ϕ3 lattice.


1993 ◽  
Vol 08 (08) ◽  
pp. 1411-1436 ◽  
Author(s):  
I.I. KOGAN ◽  
A. MOROZOV ◽  
G.W. SEMENOFF ◽  
N. WEISS

We analyze the scalar field sector of the Kazakov-Migdal model of induced QCD. We present a detailed description of the simplest one-dimensional (d=1) model which supports the hypothesis of wide applicability of the mean-field approximation for the scalar fields and the existence of critical behavior in the model when the scalar action is Gaussian. Despite the occurrence of various nontrivial types of critical behavior in the d=1 model as N→∞, only the conventional large N limit is relevant for its continuum limit. We also give a mean-field analysis of the N=2 model in anyd and show that a saddle point always exists in the region [Formula: see text]. In d=1 it exhibits critical behavior as [Formula: see text]. However when d>1 there is no critical behavior unless non-Gaussian terms are added to the scalar field action. We argue that similar behavior should occur for any finite N thus providing a simple explanation of a recent result of D. Gross. We show that critical behavior at d>1 and [Formula: see text] can be obtained by adding a logarithmic term to the scalar potential. This is equivalent to a local modification of the integration measure in the original Kazakov—Migdal model. Experience from previous studies of the Generalized Kontsevich Model implies that, unlike the inclusion of higher powers in the potential, this minor modification should not substantially alter the behavior of the Gaussian model.


1991 ◽  
Vol 43 (10) ◽  
pp. 8576-8582 ◽  
Author(s):  
Yung Qin ◽  
Z. R. Yang

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