ar X iv : h ep - l at / 9 91 10 04 v 1 4 N ov 1 99 9 RUHN - 99 – 4 Bounds on

ar X iv : h ep - l at / 9 91 10 04 v 2 3 J an 2 00 0 RUHN - 99 – 4 Bounds on the Wilson Dirac Operator

New exact upper and lower bounds are derived on the spectrum of the square of the hermitian Wilson Dirac operator. It is hoped that the derivations and the results will be of help in the search for ways to reduce the cost of simulations using the overlap Dirac operator. The bounds also apply to the Wilson Dirac operator in odd dimensions and are therefore relevant to domain wall fermions as well.

ar X iv : h ep - l at / 9 91 00 40 v 1 2 5 O ct 1 99 9 RUHN - 99 - 3 The Overlap Dirac Operator ⋆

This introductory presentation describes the Overlap Dirac Operator, why it could be useful in numerical QCD, and how it can be implemented.

ar X iv : h ep - l at / 9 91 10 02 v 1 2 N ov 1 99 9 1 The finite temperature QCD phase transition with domain wall fermions .

Results from the Columbia lattice group study of the QCD finite temperature phase transition with dynamical domain wall fermions on 16 × 4 lattices are presented. These results include an investigation of the U(1) axial symmetry breaking above but close to the transition, the use of zero temperature calculations that set the scale at the transition and preliminary measurements close to the tran...

ar X iv : h ep - l at / 9 41 10 15 v 1 9 N ov 1 99 4 1 Instanton size distributions from calibrated cooling

Using an under-relaxed cooling algorithm we investigated the vacuum in the 2d O(3) model and 4d pure gauge SU (2). We calibrated the amount of cooling performed to have similar physical effect at different lattice spacings.

ar X iv : h ep - p h / 99 11 40 8 v 1 19 N ov 1 99 9 Quark Matter 99 Summary : Hadronic Signals