Topological configurations of the magnetic field play key roles in dynamics space plasmas. This study presents a novel algorithm that can estimate quadratic gradient as well complete geometrical features lines, based on and current density measurements by multiple spacecraft constellation at four or more points. The explicit estimators for linear gradients, apparent velocity structure curvature...

Nonholonomic distributions and adapted frame structures on (pseudo) Riemannian manifolds of even dimension are employed to build structures equivalent to almost Kähler geometry and which allows to perform a Fedosov-like quantization of gravity. The nonlinear connection formalism that was formally elaborated for Lagrange and Finsler geometry is implemented in classical and quantum Einstein gravity.

We use various nonlinear partial differential equations to efficiently solve several surface modelling problems, including surface blending, N-sided hole filling and free-form surface fitting. The nonlinear equations used include two second order flows, two fourth order flows and two sixth order flows. These nonlinear equations are discretized based on discrete differential geometry operators. ...

Over the past 25 years, fast multi-scale algorithms such as wavelet-type pyramid transforms for hierarchical data representation, multi-grid solvers for the numerical solution of operator equations, and subdivision methods in computer-aided geometric design lead to tremendous successes in data and geometry processing, and in scientific computing in general. While linear multi-scale analysis is ...

We conduct a global, weakly nonlinear analysis of the magnetorotational instability (MRI) in a Taylor-Couette flow. This is a multiscale perturbative treatment of the nonideal, axisymmetric MRI near threshold, subject to realistic radial boundary conditions and cylindrical geometry. We analyze both the standard MRI, initialized by a constant vertical background magnetic field, and the helical M...

The well–known notions from tangent bundle geometry, like nonlinear connections and semisprays, are extended to bundle–type tangent manifolds. Also, new objects interesting from a dynamical point of view, like symmetries of nonlinear connections, are introduced. AMS Mathematics Subject Classification (2000): 58A30, 34A26, 37C10, 53C15

Microcoil resonators are a radical new geometry for high Q resonators with unique linear features. In this paper I briefly summarise their linear properties before extending the analysis to nonlinear interactions in microcoil resonators. As expected such nonlinear resonators are bistable and exhibit hysteresis. Finally I discuss possible applications and extensions to such resonators.