A theory of twisted umkehr maps
arXiv:2603.23776
Abstract
We develop a theory of umkehr maps for twisted generalized homology theories. In this theory, interesting umkehr maps, including generalizations of important classical ones, are induced by cartesian morphisms of a certain category opfibred over the category of spaces and continuous maps, making it possible to access them through universal properties.
90 pages. v2: Update reference, fix typo