A note on D-branes in group manifolds: flux quantisation and D0-charge

We show that a D-brane in a group manifold given by a (twisted) conjugacy class is characterised by a gauge invariant two-form field determined in terms of the matrix of gluing conditions. Using a quantisation argument based on the path integral one obtains the known quantisation condition for the corresponding D-branes. We find no evidence for the existence of a quantised U(1) gauge field flux. We propose an expression for the D0 charge of such D-branes.Comment: 13 pages. (v2: minor changes, some comments and references added.

A review of early warning system models

Financial crises have not declined in number, frequency or severity over the last two decades, rather the contrary. Each crisis causes enormous costs in the countries concerned. Thus, international financial institutions invest in researching early warning systems (EWS). The Early Warning System models can be made most useful to help sustain global growth and maintain financial stability, especially in light of the lessons learned from the current and past crises.Early Warning System models, financial crises

Classification and Quantum Moduli Space of D-branes in Group Manifolds

We study the classification of D-branes in all compact Lie groups including non-simply-laced ones. We also discuss the global structure of the quantum moduli space of the D-branes. D-branes are classified according to their positions in the maximal torus. We describe rank 2 cases, namely $B_2$, $C_2$, $G_2$, explicitly and construct all the D-branes in $B_r$, $C_r$, $F_4$ by the method of iterative deletion in the Dynkin diagram. The discussion of moduli space involves global issues that can be treated in terms of the exact homotopy sequence and various lattices. We also show that singular D-branes can exist at quantum mechanical level.Comment: latex2e, 13 pages, 3 figures. v4: A reference added. Version to appear in Phys. Lett.

Annealing-induced changes of the magnetic anisotropy of (Ga,Mn)As epilayers

The dependence of the magnetic anisotropy of As-capped (Ga,Mn)As epilayers on the annealing parameters - temperature and time - has been investigated. A uniaxial magnetic anisotropy is evidenced, whose orientation with respect to the crystallographic axes changes upon annealing from [-110] for the as-grown samples to [110] for the annealed samples. Both cubic an uniaxial anisotropies are tightly linked to the concentration of charge carriers, the magnitude of which is controlled by the annealing process.Comment: 3 pages, 3 figure

The institutional change and it´s implications on economic development

The guide in the elaboration of this article was the work of the famous attorney of the new institutionalism, D. North, named “Institutions, Institutional Change and Economic Performance”. His central idea was focused on the retaining wall of the necessity of an institutional change that to permit the economic performance. The author observes that the productive activity depends in an essential way by the institutionalization on property rights and by the observance of the contracts. If a system of property is institutionalized in a good manner and in same time he’s stable, then we can talk about by a fosterage of the investments on a long term, in these way facilities the productive activity. On the contrary, when the property is affected by risks and raised costs, the peoples will be attracted to the direct gaining based on speculation and on the obtaining of one fairly substantial part by the property existing already. Considering all these, our step try to astound, essentially, the reasons for that the structures of governance must refer at an institutional change in a state, change that must generate the economic performances.institutional change, property rights, governance, economic performance

Lie-Poisson groups and the Miura transformation

We point out that the recent proof of the Kupershmidt-Wilson theorem by Cheng and Mas-Ramos is underpinned by the Lie-Poisson property of the second Gel'fand-Dickey bracket. The supersymmetric Kupershmidt-Wilson theorem is also proved along these same lines. Finally we comment on the possible repercussions in the problem of the coproduct for W-algebras.Comment: .dvi file, uses AMSFonts 2.1+, 10 pages (5 physical pages in landscape mode), no figure