Generalized simplicial chiral models
arXiv:hep-th/9905199 · doi:10.1016/S0550-3213(99)00559-3
Abstract
Using the auxiliary field representation of the simplicial chiral models on a (d-1)-dimensional simplex, the simplicial chiral models are generalized through replacing the term Tr$(AA^{\d})$ in the Lagrangian of these models by an arbitrary class function of $AA^{\d}$; $V(AA^{\d})$. This is the same method used in defining the generalized two-dimensional Yang-Mills theories (gYM_2) from ordinary YM_2. We call these models, the ``generalized simplicial chiral models''. Using the results of the one-link integral over a U(N) matrix, the large-N saddle-point equations for eigenvalue density function $\ro (z)$ in the weak ($\b >\b_c$) and strong ($\b <\b_c$) regions are computed. In d=2, where the model is in some sense related to the gYM_2 theory, the saddle-point equations are solved for $\ro (z)$ in the two regions, and the explicit value of critical point $\b_c$ is calculated for =Tr $(B=AA^{\d})$. For )=Tr,Tr, and Tr, the critical behaviour of the model at d=2 is studied, and by calculating the internal energy, it is shown that these models have a third order phase transition.
14 pages, LaTex, some minor English corrections, will be published in Nuc. Phys. B