Homotopy Representations over the Orbit Category
  Let G be a finite group. The unit sphere in a finite-dimensional orthogonal G-representation motivates the definition of homotopy representations, due to tom Dieck. We introduce an algebraic analogue, and establish its basic properties including the Borel-Smith conditions and realization by finite G-CW-complexes. 
Ian Hambleton and Ergun Yalcin
math.AT math.GT