Tours de mains

Université de Tours Parc de Grandmont

Letting the mass depend on the spin-field coupling as M 2 = m 2 − (eg/2c 2)F αβ S αβ , we propose a new set of relativistic planar equations of motion for spinning anyons. Our model can accommodate any gyromagnetic ratio g and provides us with a novel version of the Bargmann-Michel-Telegdi equations in 2 + 1 dimensions. The system becomes singular when the field takes a critical value, and, for...

Parc de Grandmont, F-37200 TOURS (France)

Dynamical (super)symmetries of monopoles and vortices (1) Abstract. The dynamical (super)symmetries for various monopole systems are reviewed. For a Dirac monopole, no smooth Runge-Lenz vector can exist; there is, however, a spectrum-generating conformal o(2, 1) dynamical symmetry that extends into osp(1/1) or osp(1/2) for spin 1/2 particles. Self-dual 't Hooft-Polyakov-type monopoles admit an ...

WARP - water mains renewal planner

Minimum-link watchman tours

We consider the problem of computing a watchman route in a polygon with holes. We show that the problem of finding a minimum-link watchman route is NP-complete, even if the holes are all convex. The proof is based on showing that the related problem of finding a minimum-link tour on a set of points in the plane is NP-complete. We provide a provably good approximation algorithm that achieves an ...

Figurative Tours and Braids

We start with a rectangular grid of points, and we connect pairs of points to form either a tour (a Hamiltonian cycle) or a braid (a collection of disjoint paths that start in the top row and end on the bottom). In each case, our goal is to design a graph that will closely resemble a grayscale target image when viewed from a distance. From up close, the graph will look like an abstract pattern....