The microscopic structure of 2D CDT coupled to matter

TL;DR

This paper investigates the microscopic structure of 2D Causal Dynamical Triangulations coupled with matter, revealing how matter influences the model's behavior and identifying critical properties that may affect its universality class.

Contribution

It constructs an effective transfer matrix for 2D CDT with matter and analyzes its properties to explain different behaviors from pure CDT, highlighting critical exponents.

Findings

Effective transfer matrix exists for mass squared ≥ 0.05

Matter coupling alters CDT behavior significantly

Critical exponent identified may determine universality class

Abstract

We show that for 1+1 dimensional Causal Dynamical Triangulations (CDT) coupled to 4 massive scalar fields one can construct an effective transfer matrix if the masses squared is larger than or equal to 0.05. The properties of this transfer matrix can explain why CDT coupled to matter can behave completely different from "pure" CDT. We identify the important critical exponent in the effective action, which may determine the universality class of the model.