On the Hamilton-Jacobi equation for second class constrained systems

We discuss a general procedure for arriving at the Hamilton-Jacobi equation of second-class constrained systems, and illustrate it in terms of a number of examples by explicitely obtaining the respective Hamilton principal function, and verifying that it leads to the correct solution to the Euler-Lagrange equations.Comment: 17 pages, to appear in Ann. Phy

BRST Analysis of QCD_2 as a Perturbed WZW Theory

Integrability of Quantum Chromodynamics in 1+1 dimensions has recently been suggested by formulating it as a perturbed conformal Wess-Zumino-Witten Theory. The present paper further elucidates this formulation, by presenting a detailed BRST analysis.Comment: 14 pages, LaTe

Effect of using the Wisconsin design for reading skill development on the reading achievement of fourth grade pupils

The purpose of this study was to measure the effect of using the Wisconsin Design for Reading Skill Development in the teaching of reading to fourth grade pupils. Since the Wisconsin Design for Reading Skill Development is fairly new, and in the process of being field tested, such research could be a valuable indicator of its worth as a teaching procedure. Three factors were considered in the development of the objective: 1. Would an intensive program in word attack skills increase reading achievement in grade four? 2. Would the results be sufficient to warrant the incorporation of this instruction into the regular program? 3. Would an intensive program benefit all children

Lattice sum rules for the colour fields

We analyse the sum rules describing the action and energy in the colour fields around glueballs, torelons and static potentials.Comment: 9 pages LATEX, (typos corrected, to appear in Phys Rev D

Asymptotic behavior of age-structured and delayed Lotka-Volterra models

In this work we investigate some asymptotic properties of an age-structured Lotka-Volterra model, where a specific choice of the functional parameters allows us to formulate it as a delayed problem, for which we prove the existence of a unique coexistence equilibrium and characterize the existence of a periodic solution. We also exhibit a Lyapunov functional that enables us to reduce the attractive set to either the nontrivial equilibrium or to a periodic solution. We then prove the asymptotic stability of the nontrivial equilibrium where, depending on the existence of the periodic trajectory, we make explicit the basin of attraction of the equilibrium. Finally, we prove that these results can be extended to the initial PDE problem.Comment: 29 page

Measure of the path integral in lattice gauge theory

We show how to construct the measure of the path integral in lattice gauge theory. This measure contains a factor beyond the standard Haar measure. Such factor becomes relevant for the calculation of a single transition amplitude (in contrast to the calculation of ratios of amplitudes). Single amplitudes are required for computation of the partition function and the free energy. For U(1) lattice gauge theory, we present a numerical simulation of the transition amplitude comparing the path integral with the evolution in terms of the Hamiltonian, showing good agreement.Comment: 5 pages, 2 figure