It is proved that if an algebra R over a field can be endowed with a pointed and finite-dimensional .nfiltration such that the associated .n-graded algebra T is semi-commutative, then R is left and right finitely partitive. In order to do this, a multi-variable Poincare! series for every finitely generated graded T-module is considered and it is shown that this Poincare! series is a rational fu...

This article reviews the construction and some applications of twisted Poincare-covariant quantum fields on Moyal plane. The Drinfeld twist, which plays a key mathematical role in this construction, is then applied to case discrete groups, with view geons gravity. Poincare-twisted can also be study CMB anisotropies, corrections power spectrum are used put constraints spacetime noncommutativity....

For M and N closed oriented connected smooth manifolds of the same dimension, we consider the mapping space Map(M, N ; f) of continuous maps homotopic to f : M → N . We will show that the evaluation map from the space of maps to the manifold N induces a nontrivial homomorphism on the fundamental group only if the self coincidence number of f , denoted Λf,f , equals zero. Since Λf,f is equal to ...

It is shown that Poincare* duality groups which satisfy the maximal condition on centralisers have a canonical decomposition as the fundamental group of a finite graph of groups in which the edge groups are polycyclic-by-finite. The results give useful information only when there are large polycyclic subgroups. Since 3-manifolds groups satisfy Max-c, the results provide a purely grouptheoretic ...

Abstract: In this paper, the nonlinear dynamical behaviors of an active magnetic bearing-rotor system are investigated using numerical simulation. Firstly, the nonlinear magnetic force is obtained by Taylor series. Secondly, the primary-internal resonance of an AMBRS(active magnetic bearing) -rotor system is studied with the help of LungKutta method. To analyze the motion characters of system, ...

Poincare half-maps can be used to characterize the behavior of recurrent dynamical systems. Their usefulness is demonstrated for a linear three-dimensional single-loop feedback system. In this example everything can be calculated analytically. The resulting half-maps are "benign" endomorphic maps with a complicated topological structure. This is surprising since the combination of two such half...