11,950 research outputs found

### Chiral determinant on the lattice -- Anomalies and Instantons

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

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,
$(\frac{\mu_i}{q_i} -\frac{\mu_1}{q_1})$, for $i=2,...$, where $q_i$, $i=1...$
are integer valued charges of the various flavors and $\mu_i$, $i=1...$ 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

Dirac fermions in the fundamental representation of SU(N) live on the surface
of a cylinder embedded in $R^3$ and interact with a three dimensional SU(N)
Yang Mills vector potential preserving a global chiral symmetry at finite $N$.
As the circumference of the cylinder is varied from small to large, the chiral
symmetry gets spontaneously broken in the infinite $N$ 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

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

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

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

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