Electronic Thesis and Dissertation Repository


Doctor of Philosophy




Franz, Matthias.


For a compact smooth manifold with a torus action, its equivariant cohomology is a finitely generated module over a polynomial ring encoding information about the space and the action. For such a module, we can associate a purely algebraic notion called syzygy order. Syzygy order of equivariant cohomology is closely related to the exactness of Atiyah-Bredon sequence in equivariant cohomology. In this thesis we study a family of compact orientable manifolds with torus actions called big polygon spaces. We compute the syzygy orders of their equivariant cohomologies. The main tool used is a quotient criterion for syzygies in equivariant cohomology. We also generalize a lacunary principle for Morse-Bott functions to manifolds with corners in the process of computation. Some applications of the main result are discussed in the end.