The eigenvalue spectrum for dynamical Chirally Improved fermions

TL;DR

This paper compares eigenvalues of Dirac operators in QCD with dynamical fermions using Chirally Improved and overlap operators, applying Random Matrix Theory to determine the chiral condensate.

Contribution

It provides a comparison between the eigenvalues of the Chirally Improved and overlap Dirac operators in dynamical QCD configurations, and uses RMT to extract the chiral condensate.

Findings

Eigenvalues of CI and overlap operators are compared.

RMT successfully determines the chiral condensate.

Results support the validity of CI fermions in QCD simulations.

Abstract

We study the eigenvalues of Dirac operators in QCD with two mass degenerate dynamical fermions. The gauge configurations have been obtained with HMC and the so-called Chirally Improved fermionic action. We compare eigenvalues obtained for the overlap Dirac operator on these configurations with those for the Chirally Improved (CI) operator (studied earlier). Results of Random Matrix Theory allow us to determine the chiral condensate.