Joh. de Vries, W.H. Vroom, T. de Graaf, Wereldwijd bankieren. ABN AMRO 1824-1999

Willem A . de Graaf

Hugo De Vries

Modal De Vries Algebras

We introduce modal de Vries algebras and develop a duality between the category of modal de Vries algebras and the category of coalgebras for the Vietoris functor on compact Hausdorff spaces. This duality serves as a common generalization of de Vries duality between de Vries algebras and compact Hausdorff spaces, and the duality between modal algebras and modal spaces.

Coupled Korteweg-de Vries equations

When a system supports two distinct long-wave modes with nearly coincident phase speeds, the weakly nonlinear and linear dispersion unfolding generically leads to two coupled Korteweg-de Vries equations. In this paper, we review the derivation of such systems in stratified fluids, extending previous studies by allowing for background shear flows. Coupled Korteweg-de Vries systems have very rich...

Kinematic Spaces and De Vries Algebras: towards Possible Physical Meaning of De Vries Algebras

Traditionally, in physics, space-times are described by (pseudo-)Riemann spaces, i.e., by smooth manifolds with a tensor metric field. However, in several physically interesting situations smoothness is violated: near the Big Bang, at the black holes, and on the microlevel, when we take into account quantum effects. In all these situations, what remains is causality – an ordering relation. To d...