Partial Dynamical Symmetry in a Fermionic Many-Body System

The concept of partial symmetry is introduced for an interacting fermion system. The associated Hamiltonians are shown to be closely related to a realistic nuclear quadrupole-quadrupole interaction. An application to $^{12}$C is presented.Comment: 4 pages, 2 figures, Proc. Int. Conf. "Bologna 2000 - Structure of the Nucleus at the Dawn of the Century", Bologna, Italy, May 29 - June 3, 200

Composite powerplant and shroud therefor Patent

Shrouded composite propulsion system configuratio

Two-component higher order Camassa-Holm systems with fractional inertia operator: a geometric approach

In the following we study the qualitative properties of solutions to the geodesic flow induced by a higher order two-component Camassa-Holm system. In particular, criteria to ensure the existence of temporally global solutions are presented. Moreover in the metric case, and for inertia operators of order higher than three, the flow is shown to be geodesically complete.Comment: 13 page

Attitude and propellant flow control system and method Patent

Attitude and propellant flow control system for liquid propellant rocket vehicle

Steady water waves with multiple critical layers

We construct small-amplitude periodic water waves with multiple critical layers. In addition to waves with arbitrarily many critical layers and a single crest in each period, two-dimensional sets of waves with several crests and troughs in each period are found. The setting is that of steady two-dimensional finite-depth gravity water waves with vorticity.Comment: 16 pages, 2 figures. As accepted for publication in SIAM J. Math. Ana