In addition to the many diierent Nielsen-type numbers that have been introduced to study xed points, there are Nielsen-type numbers that have been created to study coincidences of maps; intersections of maps; and preimages of maps. These problems, while distinct, are all similar, and the Nielsen theories that have been created to study them display strong structural similarities as well. In thi...

A bstract The flavour problem of the Standard Model can be addressed through Froggatt-Nielsen (FN) mechanism. In this work, we develop an approach to study FN textures building a direct link between FN-charge assignments and measured masses mixing angles via unitary transformations in space. We specifically focus on quark sector identify most economic models able provide dynamical natural under...

The relationship between xed point theory and K {theory is explained, both classical Nielsen theory (versus K 0) and 1{parameter xed point theory (versus K 1). In particular, various zeta functions associated with suspension ows are shown to come in a natural way as \traces" of \torsions" of Whitehead and Reidemeister type.