Consider a maximal amenable subgroup H in a discrete countable group G. In this talk I will give a general condition implying that the von Neumann subalgebra LH is still maximal amenable inside LG. The condition is expressed in terms of H-invariant measures on some compact G-space. As an example I will show that the subgroup of upper triangular matrices inside SL(n,Z) gives rise to a maximal am...

We extend the topos-theoretic treatment given in previous papers [1, 2] of assigning values to quantities in quantum theory, and of related issues such as the Kochen-Specker theorem. This extension has two main parts: the use of von Neumann algebras as a base category (Section 2); and the relation of our generalized valuations to (i) the assignment to quantities of intervals of real numbers, an...

In this paper, von Neumann entropy is used to study three kinds of bipartite qutrit model, which represent SU(3) strongly correlated model, three-level Lipkin-Meshkov-Glick model, and spin-1 model. The relation between the ground-state entanglement and the quantum phase transition in those models is exhibited and the connection between the entanglement extremes and the symmetries is also discus...

This paper presents preliminary data on the effects of physical exercise and virtual reality upon mood and cognition in severely brain injured adults. The work draws upon two established fields of experimental psychology, enriched environments and physical exercise, in order to propose a new orientation for neurological rehabilitation. The results will be discussed in relation to organisation a...

We apply the von Neumann-Morgenstern stable set to the n-player cake division problem. Only time-preferences á la Rubinstein (1982) are assumed. The stable set is defined with respect to the following dominance relation: x dominates y if there is a player who prefers x over y even with one period lag. The Nash bargaining solution is characterized in the language of stable sets. Through the char...

We consider a class of quantum dissipative semigroup on a von-Neumann algebra which admits a normal invariant state. We investigate asymptotic behavior of the dissipative dynamics and their relation to that of the canonical Markov shift. In case the normal invariant state is also faithful, we also extend the notion of ‘quantum detailed balance’ introduced by Frigerio-Gorini and prove that forwa...

The relation between the restricted path integral approach to quantum measurement theory and the commonly accepted von Neumann wavefunction collapse postulate is presented. It is argued that in the limit of impulsive measurements the two approaches lead to the same predictions. The example of repeated impulsive quantum measurements of position performed on a harmonic oscillator is discussed in ...

We discuss skewed parton distributions in the coordinate space. Solution of the corresponding LO evolution equation is constructed in terms of eigenfunctions of the evolution kernel and its relation to the conformal symmetry is explained. Talk given at the XVth International Conference on Particles And Nuclei, June 10-16, 1999 Uppsala, Sweden Alexander von Humboldt fellow, on leave from Petersb...

This paper discusses different approaches in cognitive science and artificial intelligence research from the perspective of radical constructivism, addressing especially their relation to the biologically based theories of von Uexküll, Piaget as well as Maturana and Varela. In particular recent work in ‘New AI’ and adaptive robotics on situated and embodied intelligence is examined, and we disc...

The well-known von Neumann inequality for commuting row contractions can be interpreted as saying that the tuple (Mz1 , . . . ,Mzn) on the Drury-Arveson space H 2 n dominates every other commuting row contraction (A1, . . . , An). We show that a similar domination relation exists among certain pairs of “lessor” row contractions (B1, . . . , Bn) and (A1, . . . , An). This hints at a possible hie...