I am very honoured and pleased to participate in the commemoration of the 50 th anniversary of the founding of the CWI of the Dutch Foundation Mathematical Centre. The subject of my talk is concerned not with diierential equations but with something that is used all the time in various nonlinear analytic problems , namely degree theory. It seems particularly appropriate to speak on this subject...

We construct, for the first time, an off-shell supersymmetric continuous spin gauge theory in 4-dimensional Minkowski spacetime, both constrained and unconstrained Lagrangian formulations. As extension to on-shell description [1], we employ auxiliary field close algebra of supersymmetry transformations off-shell. The 4d $\mathcal{N}=1$ massless supermultiplet is then denoted by $(\mathrm{\Phi},...

in this study a simple and general chemical association theory is introduced. the concept of infinite equilibrium model is re-examined and true mole fractions of associated species are calculated. the theory is applied to derive the distribution function of associated species. as a severe test the application of presented theory to the van der waals mixture model is introduced in order to perfo...