11,950 research outputs found

    Chiral determinant on the lattice -- Anomalies and Instantons

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    An expression for the lattice effective action induced by chiral fermions in any even dimensions in terms of an overlap of two states is shown to have promising properties in two and four dimensions: The correct abelian anomaly is reproduced and gauge field configurations with non-zero topological charge are completely suppressed.Comment: 3 pages, ps-fil

    QED at a finite chemical potential

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    We consider multi-flavor QED on a finite lattice at a finite chemical potential and show that the partition function only depends on the variables, (μiqiμ1q1)(\frac{\mu_i}{q_i} -\frac{\mu_1}{q_1}), for i=2,...i=2,..., where qiq_i, i=1...i=1... are integer valued charges of the various flavors and μi\mu_i, i=1...i=1... are the dimensional chemical potentials of the various flavors.Comment: 9 pages, 4 figures, minor changes to match the version to appear in Physical Review

    Two dimensional fermions in three dimensional YM

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    Dirac fermions in the fundamental representation of SU(N) live on the surface of a cylinder embedded in R3R^3 and interact with a three dimensional SU(N) Yang Mills vector potential preserving a global chiral symmetry at finite NN. As the circumference of the cylinder is varied from small to large, the chiral symmetry gets spontaneously broken in the infinite NN limit at a typical bulk scale. Replacing three dimensional YM by four dimensional YM introduces non-trivial renormalization effects.Comment: 21 pages, 7 figures, 5 table

    Ginsparg-Wilson relation and the overlap formula

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    The fermionic determinant of a lattice Dirac operator that obeys the Ginsparg-Wilson relation factorizes into two factors that are complex conjugate of each other. Each factor is naturally associated with a single chiral fermion and can be realized as a overlap of two many body vacua.Comment: 4 pages, plain tex, no figure

    The overlap lattice Dirac operator and dynamical fermions

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    I show how to avoid a two level nested conjugate gradient procedure in the context of Hybrid Monte Carlo with the overlap fermionic action. The resulting procedure is quite similar to Hybrid Monte Carlo with domain wall fermions, but is more flexible and therefore has some potential worth exploring.Comment: Further expanded version. 12 pages, plain Te

    Large-N reduction of SU(N) Yang-Mills theory with massive adjoint overlap fermions

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    We study four dimensional large-N SU(N) Yang-Mills theory coupled to adjoint overlap fermions on a single site lattice. Lattice simulations along with perturbation theory show that the bare quark mass has to be taken to zero as one takes the continuum limit in order to be in the physically relevant center-symmetric phase. But, it seems that it is possible to take the continuum limit with any renormalized quark mass and still be in the center-symmetric physics. We have also conducted a study of the correlations between Polyakov loop operators in different directions and obtained the range for the Wilson mass parameter that enters the overlap Dirac operator.Comment: 8 pages, 5 figure