English

Nielsen coincidence theory for $(n,1)$-valued pairs

Algebraic Topology 2026-04-01 v1

Abstract

We generalise Nielsen theory to coincidences of pairs (f,g)(f,g) where f:XYf:X\multimap Y is nn-valued multimap and g:XYg:X\to Y is a single-valued map, for XX and YY closed oriented triangulable manifolds of equal dimension. We prove a Wecken theorem in this setting, and formulas for the Nielsen, Lefschetz and Reidemeister numbers in terms of the analogous invariants for single-valued maps. If XX and YY are orientable infra-nilmanifolds, we derive explicit formulas in terms of the fundamental group morphisms of ff and gg.

Keywords

Cite

@article{arxiv.2603.29314,
  title  = {Nielsen coincidence theory for $(n,1)$-valued pairs},
  author = {Karel Dekimpe and Lore De Weerdt},
  journal= {arXiv preprint arXiv:2603.29314},
  year   = {2026}
}

Comments

47 pages, 3 figures