Higher Dimensional SUSY Quantum Mechanics

Higher dimensional supersymmetric quantum mechanics is studied. General properties of the two dimensional case are presented. For three spatial dimesions or higher, a spin structure is shown to arise naturally from the nonrelativistic supersymmetry algebra.Comment: 8 pages, Late

Analysis of Latin America's Corporations as a Rational Response to the Economic Environment Present in the Region - Part I

This is the first of a series of working papers analyzing the basic characteristics of the economic environment in which Latin American Corporations live and the optimal design of incentive programs compatible with such environment. By economic environment we mean the technology that the organizations have access to, the legal framework present in these countries, the macro-economical characteristics, the markets in which they operate (competitors, monopolies, customers, reliability of suppliers, etc.), the nature of their capital markets and in general of the sources of financing for their companies, etc. We could broadly say that any key feature of the economy that has the potential to influence the way business is run in Latin America is part of its economic environment. The underlying unifying idea in this series is that, unless we have clear evidence to the contrary, corporate practices observed in Latin American firms are rational responses to the environment in which they operate. They are a sort of Darwinian adaptation to such environment. Therefore, much like in biological systems, these characteristics of corporations should be considered optimal in a relative sense. That is, in order to survive in the market, the observed corporate practices should be better that the ones from the competition for the given economic environment. This observation suggests that improvements to the observed practices are indeed possible. In fact, the present series of working papers is in part structured to explore possible improvements. These improvements, however, are not likely to be the simple copy of corporate practices that evolved as an optimal response to the environment of the developed world. In this first work we present some important empirical characteristics of the Latin American Corporations and the first key aspect of the economic environment prevailing in this region: the legal framework. We show how many of the empirical characteristics presented can be see as optimal responses to the legal framework.

Quantum-classical transition and quantum activation of ratchet currents in the parameter space

The quantum ratchet current is studied in the parameter space of the dissipative kicked rotor model coupled to a zero temperature quantum environment. We show that vacuum fluctuations blur the generic isoperiodic stable structures found in the classical case. Such structures tend to survive when a measure of statistical dependence between the quantum and classical currents are displayed in the parameter space. In addition, we show that quantum fluctuations can be used to overcome transport barriers in the phase space. Related quantum ratchet current activation regions are spotted in the parameter space. Results are discussed {based on quantum, semiclassical and classical calculations. While the semiclassical dynamics involves vacuum fluctuations, the classical map is driven by thermal noise.Comment: 6 pages, 3 figure

Analysis of Latin America's corporations as a rational response to the economic environment present in the region. Part I. Corporate governance: Empirical characteristics and the legal framework

This is the first of a series of working papers analyzing the basic characteristics of the economic environment in which Latin American Corporations live and the optimal design of incentive programs compatible with such environment. By economic environment we mean the technology that the organizations have access to, the legal framework present in these countries, the macro-economical characteristics, the markets in which they operate (competitors, monopolies, customers, reliability of suppliers, etc.), the nature of their capital markets and in general of the sources of financing for their companies, etc. We could broadly say that any key feature of the economy that has the potential to influence the way business is run in Latin America is part of its economic environment. The underlying unifying idea in this series is that, unless we have clear evidence to the contrary, corporate practices observed in Latin American firms are rational responses to the environment in which they operate. They are a sort of Darwinian adaptation to such environment. Therefore, much like in biological systems, these characteristics of corporations should be considered optimal in a relative sense. That is, in order to survive in the market, the observed corporate practices should be better that the ones from the competition for the given economic environment. This observation suggests that improvements to the observed practices are indeed possible. In fact, the present series of working papers is in part structured to explore possible improvements. These improvements, however, are not likely to be the simple copy of corporate practices that evolved as an optimal response to the environment of the developed world. In this first work we present some important empirical characteristics of the Latin American Corporations and the first key aspect of the economic environment prevailing in this region: the legal framework. We show how many of the empirical characteristics presented can be see as optimal responses to the legal framework

On the Divergence of Perturbation Theory: Steps Towards a Convergent Series

The mechanism underlying the divergence of perturbation theory is exposed. This is done through a detailed study of the violation of the hypothesis of the Dominated Convergence Theorem of Lebesgue using familiar techniques of Quantum Field Theory. That theorem governs the validity (or lack of it) of the formal manipulations done to generate the perturbative series in the functional integral formalism. The aspects of the perturbative series that need to be modified to obtain a convergent series are presented. Useful tools for a practical implementation of these modifications are developed. Some resummation methods are analyzed in the light of the above mentioned mechanism

Matching Current Correlators in Lattice QCD to Chiral Perturbation Theory

Chiral perturbation theory gives direct and unambiguous predictions for the form of various two-point hadronic correlators at low momentum in terms of a finite set of couplings in a chiral Lagrangian. In this paper we study the feasibility of extracting the couplings in the chiral Lagrangian (through 1-loop order) by fitting two-point correlators computed in lattice QCD to the predicted chiral form. The correlators are computed using a pseudofermion technique yielding all-point quark propagators which allows the computation of the full four-momentum transform of the two-point functions to be obtained without sacrificing any of the physical content of the unquenched gauge configurations used. Results are given for an ensemble of dynamical configurations generated using the truncated determinant algorithm on a large coarse lattice. We also present a new analysis of finite volume effects based on a finite volume dimensional regularization scheme which preserves the power-counting rules appropriate for a chiral Lagrangian

Analysis of Latin America's corporations as a rational response to the economic environment present in the region. Part III. Quantifying Latin American firms' exposure to external factors

This is the last of a series of three working papers analyzing the basic characteristics of the economic environment in which Latin American firms operate and the optimal design of incentive programs compatible with such environment. Executive pay-for-performance compensation schemes are usually based on stock returns. However, stock returns change in response to forces beyond management control (e.g., market crushes). The economic environment in which Latin American firms operate is highly unstable, which means that this is a very important limitation for Latin American firms. In the present paper, we present a procedure to decompose variability in stock returns in order to identify and measure components that respond to external factors beyond management control. For this, we have created indices that capture statistically the external influences that affect stock returns. We show how such indices can be used to construct a risk profile that allows management to know to what extent observed outcomes depend on external factors, versus their own actions. In addition, these indices can be used as a basis to develop indexed options: financial instruments designed to factor out the effects of external risks, making it possible for executives to be evaluated only on the basis of the value they generate. We show that these indices can be developed out of purely local information, but that the solutions tend to be moderately unstable, which implies that compensation instruments developed with this methodology should be of relatively short maturity