The pursuit of better atomic clocks has advanced many research areas, providing better quantum state control, new insights in quantum science, tighter limits on fundamental constant variation and improved tests of relativity. The record for the best stability and accuracy is currently held by optical lattice clocks. Here we take an important step towards realizing the full potential of a many-p...

We review research (our own and others’) on communities of practice. Crucial dimensions of analysis include the balance between virtual and physical interactions, and the roles of people within the communities of practice.

A fast algorithm is established to transform points of the unit sphere into fundamental region symmetrically. With the resulting algorithm, a flexible form of invariant mappings is achieved to generate aesthetic patterns with symmetries of the regular polyhedra.

In advanced robotic applications where a physical interaction of the robot with the environment takes place, the measurement of interaction forces is of basic importance for a safe execution of the desired tasks. In this paper, a novel ‘stress’ sensor is presented and its basic characteristics illustrated and discussed. Among its positive features, one may find the very compact size, good elect...

The contribution provides the background of the model of Expansive Nondecelerative Universe, rationalizes the introduction of Vaidya metrics allowing thus to localize and quantify gravitational energy. A unifying explanation of the fundamental physical interactions is accompanied by demonstration of some consequences and predictions relating to cosmological problems.

We calculate the constraints on the constants of hypothetical long-range interactions which follow from the recent measurement of the Casimir force. A comparison with previous constraints is given. The new constraints are up to a factor of 3000 stronger in some parameter regions .

In the study of Fuchsian groups, it is a nontrivial problem to determine a set of generators. Using a dynamical approach we construct for any cocompact arithmetic Fuchsian group a fundamental region in SL2(R) from which we determine a set of small generators.

In this paper we argue that a set of fundamental forces has driven modern communication services to become highly centralized. This centralization has enabled globe spanning communication infrastructure and services to be built, but has also enabled powerful actors to monitor and control communications on an unprecedented scale. As a counterbalancing force we propose a Liberouter network, which...

Let G be a connected linear Lie group which finitely covers the isometry group of X. Furthermore, let Γ ⊂ G be a discrete subgroup. We assume that Γ is geometrically finite. We refer to Definition 2.1 for a precise explanation of this notion. If X is a real hyperbolic space, then Γ is geometrically finite iff it admits a fundamental domain with finitely many totally geodesic faces. In the other...