A solution to de Groot's absolute cone conjecture

A compactum X is an `absolute cone' if, for each of its points x, the space X is homeomorphic to a cone with x corresponding to the cone point. In 1971, J. de Groot conjectured that each n-dimensional absolute cone is an n-cell. In this paper, we give a complete solution to that conjecture. In particular, we show that the conjecture is true for n<4 and false for n>4. For n=4, the absolute cone conjecture is true if and only if the 3-dimensional Poincare Conjecture is true.