On Phase Transition of Two-Dimensional Topological Gravity
Jian Zhou
TL;DR
The paper develops a unified, renormalized-coordinates framework for two-dimensional topological gravity, enabling uniform computation of genus-$g$ free energies $F_g$ and correlation functions at all multicritical points. By introducing renormalized couplings $I_k$ (via the Itzykson–Zuber construction) and expressing observables in $I$-coordinates, the authors derive explicit, polynomial expressions for $F_g$ (with weights and degrees fixed) and loop/n-point functions across genera. They verify the uniform approach through concrete analyses of the pure gravity ($k=2$) and Yang–Lee edge ($k=3$) critical points, obtaining detailed I-coordinate representations, $F_g$ weightings, and explicit correlator forms, including cases with $t_n=0$ for $n eq0,1,k$. The results reproduce and illuminate the DDK/KPZ scaling exponents and suggest a path to extend to broader $(p,q)$ minimal models and $r$-spin theories, highlighting a cohesive phase-structure picture for 2D topological gravity.
Abstract
We show that one can use some renormalized coupling constants to compute the free energy and correlation functions at all critical points of the two-dimensional topological gravity in a uniform way. In particular, one can derive the critical exponents of the free energy and correlation functions at all critical points in a uniform way. Some concrete results for the case of $(3,2)$-model (pure gravity) and the $(5,2)$-model (Yang-Lee edge singularity coupled with gravity) are also presented.
