We introduce a new invariant S (M) for type III factors M with no almost-periodic weights. We compute this invariant for certain free Araki-Woods factors. We show that Connes’ invariant τ cannot distinguish all isomorphism classes of free Araki-Woods factors. We show that there exists a continuum of mutually non-isomorphic free Araki-Woods factors, each without almostperiodic weights.

2. A topological classification of the almost periodic homeomorphisms on a closed 2-cell. A homeomorphism A of a metric space (X, p) onto itself is said to be almost periodic on X if €>0 implies that there exists a relatively dense sequence {«¿} of integers such that p(x, A"*'(x)) <e for all xGA and i= ±1, ±2, • • •. A homeomorphism A of the space X onto itself is said to be topologically equiv...

We investigate spectral properties of the translation action on the orbit closure of a Delone set. In particular, suucient conditions for pure discrete spectrum are given, based on the notion of almost periodicity. Connections with diiraction spectrum are discussed.

By means of Mawhin’s continuation theorem of coincidence degree theory, some new sufficient conditions are obtained for the existence of at least four positive almost periodic solutions for a harvesting mutualism model with time delays. To the best of the author’s knowledge, so far, the result of this paper is completely new. An example is employed to illustrate the result of this paper.

The problem of strict convexity of the Besicovitch-Orlicz space of almost periodic functions is considered here in connection with the Orlicz norm. We give necessary and sufficient conditions in terms of the function φ generating the space. 2000 Mathematics Subject Classification: 46B20, 42A75.

We prove separation of variables for the most general (Dn type) periodic Toda lattice with 2 × 2 Lax matrix. It is achieved by finding proper normalisation for the corresponding Baker-Akhiezer function. Separation of variables for all other periodic Toda lattices associated with infinite series of root systems follows by taking appropriate limits.

let x=(xi, • • ■ , xn) and /=(fi, • • • ,/„), and suppose that / is of class C1. A set, 12, of points x will be called unrestricted if, whenever a point x0 is in 12, the solution path x = x(t), where x0 = x(0), exists for — co </< oo and lies in 12. Two types of stability distinguished simply by "A" and "B" will be considered: (A) Let the value to be arbitrary but fixed. A solution x — x(t) of ...

In this paper, by applying Mawhin’s continuation theorem of coincidence degree theory, we study the existence of almost periodic solutions for neural multi-delay logarithmic population model and obtain one sufficient condition for the existence of positive almost periodic solution for the above equation. An example is employed to illustrate our result. Keywords—Almost periodic solution; Multi-d...

The paper examines the existence of pseudo almost periodic solutions to some classes of partial hyperbolic evolution equations. Namely, sufficient conditions for the existence and uniqueness of pseudo almost periodic solutions to those classes of hyperbolic evolution equations are given. Applications include the existence of pseudo almost periodic solutions to the transport and heat equations w...

We prove that one-dimensional Schrödinger operators with even almost periodic potential have no point spectrum for a dense Gδ in the hull. This implies purely singular continuous spectrum for the almost Mathieu equation for coupling larger than 2 and a dense Gδ in θ even if the frequency is an irrational with good Diophantine properties. §