This volume contains the proceedings of the AMS Special Session on Ends and Boundaries of Groups, held in honor of Michael Mihalik's 70th birthday, from April 15-16, 2023, at the University of Cincinnati, Cincinnati, Ohio. The papers cover current topics in geometric group theory and related topology. Four survey papers discuss hyperbolic actions, CAT(0) groups, Thompson-type groups and $Z$-set boundaries. Other papers cover new material related to hyperbolic groups, Poincare Duality groups, outer automorphism groups, right angled Artin groups, and mapping class groups. Several papers present new results on ends of spaces and related group theory. A notable addition, intended for readers interested in the interplay of topology and group theory, is a self-contained detailed exposition of $Z$-sets and their role in geometric group theory.
Articles
Yael Algom-Kfir and Mladen Bestvina, Groups of proper homotopy equivalences
of graphs and Nielsen Realization
Fredric D. Ancel, Z-sets in ANRs
Liam Axon and Jack Calcut, The End Sum of Surfaces
Sahana H. Balasubramanya, A survey on classifying hyperbolic actions of
groups
Martin R. Bridson, Dawid Kielak and Monika Kudlinska, Stallings's Fibring
Theorem and $\mathrm {PD}^3$-pairs
Noah Caplinger and Dan Margalit, Totally Symmetric Sets
M. Cardenas, F. F. Lasheras and A. Quintero, Proper $2$-equivalences and
amalgams over virtually free groups
Alexander Dranishnikov and Satyanath Howladar, On Gromov's conjecture for
right-angled Artin groups
Jerzy Dydak, Yuankui Ma and Hussain Rashed, Ends of large scale groups
Daniel S. Farley, The expansion set construction of classifying spaces for
generalized Thompson groups
Talia Fernos, Le Conte de la Mesure sur les Complexes Cubiques CAT(0)
Craig R. Guilbault and Daniel Gulbrandsen, A generalized theory of expansions
and collapses with applications to $\mathcal {Z}$-compactification
G. Christopher Hruska and Kim Ruane, Hyperbolic groups and local
connectivity
Nir Lazarovich and Emily Stark, Failure of quasi-isometric rigidity for
infinite-ended groups
Rylee Alanza Lyman, One-endedness of outer automorphism groups of free
products of finite and cyclic groups
Molly A. Moran, A brief survey of $\mathcal {Z}$-boundaries
Ross Geoghegan, Binghamton University, NY, Craig R. Guilbault, University of Wisconsin, Milwaukee, WI.
Kim Ruane, Tufts University, Medford, MA.
