708 research outputs found
Magnetic Monopoles, Center Vortices, Confinement and Topology of Gauge Fields
The vortex picture of confinement is studied. The deconfinement phase
transition is explained as a transition from a phase in which vortices
percolate to a phase of small vortices. Lattice results are presented in
support of this scenario. Furthermore the topological properties of magnetic
monopoles and center vortices arising, respectively, in Abelian and center
gauges are studied in continuum Yang-Mills-theory. For this purpose the
continuum analog of the maximum center gauge is constructed.Comment: talk given by H. Reinhardt on the Int. Workshop ``Hadrons 1999'',
Coimbra, 10.-15. Sept. 199
Magnetic Monopoles, Center Vortices and Topology of Gauge Fields
The topological properties of magnetic monopoles and center vortices arising,
respectively, in Abelian and center gauges are studied in continuum Yang-Mills
Theory. For this purpose the continuum analog of the maximum center gauge is
constructed.Comment: talk presented at LATTICE99(topology) at Pisa, Italy, 3 page
Energies of Quantum QED Flux Tubes
In this talk I present recent studies on vacuum polarization energies and
energy densities induced by QED flux tubes. I focus on comparing three and four
dimensional scenarios and the discussion of various approximation schemes in
view of the exact treatment.Comment: 9 pages latex, Talk presented at the QFEXT 05 workshop in Barcelona,
Sept. 2005. To appear in the proceeding
Thermal stability of the ferromagnetic in-plane uniaxial anisotropy of Fe-Co-Hf-N/Ti-N multilayer films for high-frequency sensor applications
Boron Fullerenes: A First-Principles Study
A family of unusually stable boron cages was identified and examined using
first-principles local density functional method. The structure of the
fullerenes is similar to that of the B12 icosahedron and consists of six
crossing double-rings. The energetically most stable fullerene is made up of
180 boron atoms. A connection between the fullerene family and its precursors,
boron sheets, is made. We show that the most stable boron sheets are not
necessarily precursors of very stable boron cages. Our finding is a step
forward in the understanding of the structure of the recently produced boron
nanotubes.Comment: 10 pages, 4 figures, 1 tabl
On the issue of imposing boundary conditions on quantum fields
An interesting example of the deep interrelation between Physics and
Mathematics is obtained when trying to impose mathematical boundary conditions
on physical quantum fields. This procedure has recently been re-examined with
care. Comments on that and previous analysis are here provided, together with
considerations on the results of the purely mathematical zeta-function method,
in an attempt at clarifying the issue. Hadamard regularization is invoked in
order to fill the gap between the infinities appearing in the QFT renormalized
results and the finite values obtained in the literature with other procedures.Comment: 13 pages, no figure
Abelian Dominance in Wilson Loops
It has been conjectured that the Abelian projection of QCD is responsible for
the confinement of color. Using a gauge independent definition of the Abelian
projection which does {\it not} employ any gauge fixing, we provide a strong
evidence for the Abelian dominance in Wilson loop integral. In specific we
prove that the gauge potential which contributes to the Wilson loop integral is
precisely the one restricted by the Abelian projection.Comment: 4 pages, no figure, revtex. Phys. Rev. D in pres
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