A Numerical Study of the 2-Flavour Schwinger Model with Dynamical Overlap Hypercube Fermions

Abstract

We present numerical results for the 2-flavour Schwinger model with dynamical chiral lattice fermions. We insert an approximately chiral hypercube Dirac operator into the overlap formula to construct the overlap hypercube operator. This is an exact solution to the Ginsparg-Wilson relation, with an excellent level of locality and scaling. Due to its similarity with the hypercubic kernel, a low polynomial in this kernel provides a numerically efficient Hybrid Monte Carlo force. We measure the microscopic Dirac spectrum and discuss the corresponding scale-invariant parameter, which takes a surprising form. This is an interesting case, since Random Matrix Theory is unexplored for this setting, where the chiral condensate Σ vanishes in the chiral limit. We also measure Σ and the "pion" mass, in distinct topological sectors. In this context we discuss and probe the topological summation of observables by various methods, as well as the evaluation of the topological susceptibility. The feasibility of this summation is essential for the prospects of dynamical overlap fermions in QCD.

44 pages, LaTex, 12 tables, 17 figures, final version published in Eur. Phys. J. C

References in corpus (10)

• Finite volume QCD at fixed topological charge
• Two-flavor lattice QCD simulation in the epsilon-regime with exact chiral symmetry
• Topological susceptibility in two-flavor lattice QCD with exact chiral symmetry
• Lattice study of meson correlators in the epsilon-regime of two-flavor QCD
• Parameters of the lowest order chiral Lagrangian from fermion eigenvalues
• Overlap Hypercube Fermions in QCD Simulations Near the Chiral Limit
• Pion in a Box
• Quark condensate in one-flavor QCD
• Topological tunneling with Dynamical overlap fermions
• Optimised Dirac Operators on the Lattice: Construction, Properties and Applications

Cited by in corpus (13)

• The mass spectrum of the Schwinger model with Matrix Product States
• Physics of eta-prime with rooted staggered quarks
• Lattice Hamiltonian approach to the massless Schwinger model: precise extraction of the mass gap
• Dirac Spectra of 2-dimensional QCD-like theories
• Measuring the Topological Susceptibility in a Fixed Sector
• Interpreting Numerical Measurements in Fixed Topological Sectors
• Extracting hadron masses from fixed topology simulations
• Topological Susceptibility from Slabs
• Berezinskii-Kosterlitz-Thouless Transition with a Constraint Lattice Action
• Features of a 2d Gauge Theory with Vanishing Chiral Condensate
• Mass spectroscopy using Borici-Creutz fermion on 2D lattice
• Topological Susceptibility under Gradient Flow
• Bosonic Partition Functions at Nonzero (Imaginary) Chemical Potential