Generating Functional and Large N-Limit of Nonlocal 2D Generalized   Yang-Mills Theories ($nlgYM_2$'s)
  Using the path integral method, we calculate the partition function and generating functional (of the field strengths) on the nonlocal generalized 2D Yang - Mills theories ($nlgYM_2$'s), which is nonlocal in auxiliary field [14]. Our calculations is done for general surfaces. We find a general expression for free energy of $W(\phi) = \phi^{2k}$ in $nlgYM_2$ theories at the strong coupling phase (SCP) regime ($A > A_c$) for large groups. In the specific $\phi^4$ model, we show that the theory has a third order phase transition. 
Kh. Saaidi, H. M. Sadjadi