Solutions of physical equations which have non-trivial topological properties have been studied for already more than five years. As examples we may give the "monopole""2 and the ' ' in~tanton'~ in gauge field theories and the "pseudoparticle" in a two-dimensional isotropic f e r r ~ m a g n e t . ~ All these solutions a re characterized by some topological index: the magnetic charge of the mon...

New extended superspaces associated with topological charge algebras of the D-brane are used to construct D-brane actions without worldvolume gauge fields. The actions are shown to be kappa-symmetric under an appropriately chosen right group action.

We discuss the 2 + 1 dimensional Abelian Higgs model coupled to N = 2 supergravity. We construct the supercharge algebra and, from it, we show that the mass of classical static solutions is bounded from below by the topological charge. As it happens in the global case, half of the supersymmetry is broken when the bound is attained and Bogomol’nyi equations, resulting from the unbroken supersymm...

In this talk, instantons are discussed in the presence of Lorentz violation. Conventional topological arguments are applied to classify the modified solutions to the Yang-Mills equations according to the topological charge. Explicit perturbations to the instantons are calculated in detail for the case of unit topological charge.

We analyze screw, edge and mixed screw-edge dislocations in monochromatic light waves. Methods for the experimental dete~nation of the topological charge value and helicity of screw dislocations are elaborated. By use of computer-synthesized binary gratings waves with edge and mixed screw-edge disl~ations were obtained and studied ~xpe~mentally. The transformation of a mixed screw-edge distocat...

We report the details of our ongoing quenched calculations of weak matrix elements using the combination of domain-wall fermions and the DBW2 gauge action on lattices with a −1 ≈ 3 GeV. A strategy to avoid the problem of fixed topological charge is introduced in generating gauge configurations. After studying the basic run parameters and elemental quantities, we present a preliminary result for...

We report the details of our ongoing quenched calculations of weak matrix elements using the combination of domain-wall fermions and the DBW2 gauge action on lattices with a −1 ≈ 3 GeV. A strategy to avoid the problem of fixed topological charge is introduced in generating gauge configurations. After studying the basic run parameters and elemental quantities, we present a preliminary result for...

We present new static axially symmetric solutions of SU(2) Yang-Mills-Higgs theory, representing chains of monopoles and antimonopoles in static equilibrium. They correspond to saddlepoints of the energy functional and exist both in the topologically trivial sector and in the sector with topological charge one.

In this article we study two different generalizations of von Neumann regularity, namely strong topological regularity and weak regularity, in the Banach algebra context. We show that both are hereditary properties and under certain assumptions, weak regularity implies strong topological regularity. Then we consider strong topological regularity of certain concrete algebras. Moreover we obtain ...