Alladi Ramakrishnan Hall

Analyzing phase transitions with  multi-point Pade analyses: from the Ising model to lattice QCD

Christian Schmidt

Bielefeld University

We discuss a new method to study phase transitions, based on the computation of multi-point Pad\’e 
approximants and their poles in the complex plane of symmetry breaking or temperature like scaling fields. 
These poles can be identified with the Lee-Yang and Fischer zeros of the partition function and thus exhibit 
a universal scaling behavior. After reviewing the universal scaling of the zeros and some methodological 
aspects of the method, we demonstrate that it is applicable to the Ising model where it reproduces known 
results. Finally we discuss the potential applications to the QCD phase diagram, by using lattice QCD 
simulations at imaginary chemical potentials. We present preliminary results in the vicinity of the Roberge-
Weiss transition and speculate on the position of the QCD critical point.