Antisymmetric tensor fields on spheres: functional determinants and   non--local counterterms
  The Hodge--de Rham Laplacian on spheres acting on antisymmetric tensor fields is considered. Explicit expressions for the spectrum are derived in a quite direct way, confirming previous results. Associated functional determinants and the heat kernel expansion are evaluated. Using this method, new non--local counterterms in the quantum effective action are obtained, which can be expressed in terms of Betti numbers. 
E. Elizalde, M. Lygren and D.V. Vassilevich