# Reflection positivity and invertible topological phases

@article{Freed2016ReflectionPA, title={Reflection positivity and invertible topological phases}, author={Daniel S. Freed and Michael J. Hopkins}, journal={arXiv: High Energy Physics - Theory}, year={2016} }

We implement an extended version of reflection positivity (Wick-rotated unitarity) for invertible topological quantum field theories and compute the abelian group of deformation classes using stable homotopy theory. We apply these field theory considerations to lattice systems, assuming the existence and validity of low energy effective field theory approximations, and thereby produce a general formula for the group of Symmetry Protected Topological (SPT) phases in terms of Thom's bordism… Expand

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