Shapes of compacta and ANR-systems
This paper shows that the simplicial type of a finite simplicial complex is determined by its algebra of polynomial functions on the baricentric coordinates with coefficients in any integral domain. The link between and is done through certain admissible matrix associated to in a natural way. This result was obtained for the real numbers by I. V. Savel’ev [5], using methods of real algebraic geometry. D. Kan and E. Miller had shown in [2] that determines the homotopy type of the polyhedron...
Basic examples show that coincidence theory is intimately related to central subjects of differential topology and homotopy theory such as Kervaire invariants and divisibility properties of Whitehead products and of Hopf invariants. We recall some recent results and ask a few questions which seem to be important for a more comprehensive understanding.