Axel Maas
(Karl-Franzens-University Graz)
18/06/2010, 16:40
Vacuum structure and confinement
In gauge theories, all physically equivalent field configurations lie on a common gauge orbit. Selecting a particular representative on the gauge orbit fixes a gauge. This is useful for practical reasons, like to facilitate calculations of gauge-invariant observables, or to provide gauge-dependent correlation functions which can serve as input for methods other than lattice. It is also of...
Lorenz von Smekal
(TU Darmstadt)
18/06/2010, 17:00
Vacuum structure and confinement
We study center vortex free energies and ’t Hooft’s electric fluxes on the lattice in 2+1 dimensions, where SU(2) for example, is in the universality class of the 2d Ising model. This places a wealth of exact results at our fingertips. In particular, spacelike center vortices in SU(2) near criticality correspond to spin interfaces in the 2d Ising model, whose universal scaling functions are...
Akihiro Shibata
(Computing Reaearch Center, KEK)
18/06/2010, 17:20
Vacuum structure and confinement
Recently we have proposed a new reformulation of Yang-Mills (YM) theory based on new variables on a lattice by extending the Cho-Faddeev-Niemi-Shabanov decomposition. Our reformulation allows options discriminated by the stability group $\tilde{H}$ of the gauge group $G$. When $\tilde{H}$ agrees with the maximal torus group $H$, it reduces to a manifestly gauge-independent reformulation of...
Björn Wellegehausen
(TPI, University Jena)
18/06/2010, 17:40
Vacuum structure and confinement
G2 is the smallest simple and simply connected lie group with a trivial center. Therefore investigations of G2 gauge theory may help to clarify the relevance of center symmetry for confinement. Beside this it has an intriguing connection to QCD where the center symmetry is broken by dynamical quarks transforming under the fundamental representation. In both theories the flux tube between...
