Metric Lagrangians with two propagating degrees of freedom

Dynamical Systems with Two Degrees of Freedom.

Non-differentiable Degrees of Freedom : Fluctuating Metric Signature

In this article we investigate the metric signature as a non-differentiable degree of freedom. The specific model is a vacuum 7D Universe on the principal bundle with an SU(2) structural group. An analytical solution is found which to a 4D observer appears as a flat Universe with a fluctuating metric signature, and frozen extra dimensions with an SU(2) instanton gauge field. A piece of this sol...

Decoupling Multivariable Control with Two Degrees of Freedom

Low-temperature sample orienting device with two degrees of freedom.

We describe a rotating sample holder with two degrees of freedom for galvanomagnetic measurements at low temperatures which allows positioning within 0.5 degrees with a reproducibility of better than 0.5 degrees . The main advantages of our device over other constructions are simple and accurate device adjustment, simple and convenient handling, and simple and quick sample changing.

Energy Shaping for Systems with Two Degrees of Underactuation and More than Three Degrees of Freedom

We study the stabilizability, via the method of energy shaping, of a given Lagrangian system with two degrees of underactuation and with n ≥ 4 degrees of freedom. By making use of the formal theory of PDEs, we derive an involutive system of PDEs which governs energy shapability, and thus deduce, for the first time, easily verifiable conditions under which energy shaping is guaranteed. We illust...