Obstructions to homotopy invariance of loop coproduct via parametrised fixed-point theory

Lea Kenigsberg, Noah Porcelli

Given $f:M\to N$ a homotopy equivalence of compact manifolds with boundary, we use a construction of Geoghegan and Nicas to define its Reidemeister trace $[T] \in π_1^{st}(\mathc…