Dirac brackets in geometric dynamics
Dirac field on newtonian space-time
Dirac operator in contact symplectic parabolic geometry
Dirac operators on hypersurfaces
In this paper some relation among the Dirac operator on a Riemannian spin-manifold , its projection on some embedded hypersurface and the Dirac operator on with respect to the induced (called standard) spin structure are given.
Dirac structures and dynamical -matrices
The purpose of this paper is to establish a connection between various objects such as dynamical -matrices, Lie bialgebroids, and Lagrangian subalgebras. Our method relies on the theory of Dirac structures and Courant algebroids. In particular, we give a new method of classifying dynamical -matrices of simple Lie algebras , and prove that dynamical -matrices are in one-one correspondence with certain Lagrangian subalgebras of .
Dirac submanifolds and Poisson involutions
Direct approach to mean-curvature flow with topological changes
This contribution deals with the numerical simulation of dislocation dynamics. Dislocations are described by means of the evolution of a family of closed or open smooth curves , . The curves are driven by the normal velocity which is the function of curvature and the position. The evolution law reads as: . The motion law is treated using direct approach numerically solved by two schemes, i. e., backward Euler semi-implicit and semi-discrete method of lines. Numerical stability is improved...
Direct kinematics of double-triangular parallel manipulators.
Dirichlet points, Garnett points, and infinite ends of hyperbolic surfaces. I.
Dirichlet regions in manifolds without conjugate points.
Disconnected regular -manifolds
Disconnectedness of Sublevel Sets of Some Riemannian.
Disconnections of plane continua
The paper deals with locally connected continua in the Euclidean plane. Theorem 1 asserts that there exists a simple closed curve in that separates two given points , of if there is a subset of (a point or an arc) with this property. In Theorem 2 the two points , are replaced by two closed and connected disjoint subsets , . Again – under some additional preconditions – the existence of a simple closed curve disconnecting and is stated.
Discrete and nondiscrete isometric deformations of surfaces in .
Discrete isothermic surfaces.
Discrete Laplace cycles of period four
We study discrete conjugate nets whose Laplace sequence is of period four. Corresponding points of opposite nets in this cyclic sequence have equal osculating planes in different net directions, that is, they correspond in an asymptotic transformation. We show that this implies that the connecting lines of corresponding points form a discrete W-congruence. We derive some properties of discrete Laplace cycles of period four and describe two explicit methods for their construction.
Discrete minimal surface algebras.
Discrete periodic geodesics in a surface.
Discrete thickness
We investigate the relationship between a discrete version of thickness and its smooth counterpart. These discrete energies are deffned on equilateral polygons with n vertices. It will turn out that the smooth ropelength, which is the scale invariant quotient of length divided by thickness, is the Γ-limit of the discrete ropelength for n → ∞, regarding the topology induced by the Sobolev norm ‖ · ‖ W1,∞(S1,ℝd). This result directly implies the convergence of almost minimizers of the discrete energies...
Discreteness Conditions for the Laplacian on Complete, Non-Compact Riemannian Manifolds.