100 citations · 145 across the 12 of their papers we have counts for
13 papers
A conceptual model for growth by Capital-Education investments
Ferdinand Verhulst
Economic growth depends on capital investments and on investments in education and innovation. The model introduced here will specifiy aggregate output as determined by aggregate s…
Evolution to mirror-symmetric galaxies
Ferdinand Verhulst
The evolution of a rotating axisymmetric galaxy from an asymmetric state to a state of mirror symmetry with respect to the galactic plane has as basic result that in the asymmetric…
Evolution to symmetry
Ferdinand Verhulst
A natural example of evolution can be described by a time-dependent two degrees-of-freedom Hamiltonian. We choose the case where initially the Hamiltonian derives from a general cu…
Explorations for alternating FPU-chains with large mass
Wilberd van der Kallen, Ferdinand Verhulst
We show interaction between high- and low-frequency modes in periodic -FPU chains with alternating large masses. The treatment discusses the difficult case where the number of p…
Optical-acoustical interaction in FPU-chains with alternating large masses (plus appendix)
Roelof Bruggeman, Ferdinand Verhulst
One of the problems of periodic FPU-chains with alternating masses is whether significant interactions exist between the so-called (high frequency) optical and (low frequency) acou…
Variations on the Fermi-Pasta-Ulam chain, a survey
Ferdinand Verhulst
We will present a survey of low energy periodic Fermi-Pasta-Ulam chains with leading idea the "breaking of symmetry". The classical periodic FPU-chain (equal masses for all particl…