Now showing items 1-3 of 3

• #### A Cheeger Type Inequality in Finite Cayley Sum Graphs ﻿

[OWP-2019-21] (Mathematisches Forschungsinstitut Oberwolfach, 2019-07-31) - (5 May - 27 July 2019)
Let $G$ be a finite group and $S$ be a symmetric generating set of $G$ with $|S| = d$. We show that if the undirected Cayley sum graph $C_{\Sigma}(G,S)$ is an expander graph and is non-bipartite, then the spectrum of its ...
• #### Groups with Spanier-Whitehead Duality ﻿

[OWP-2019-23] (Mathematisches Forschungsinstitut Oberwolfach, 2019-09-17)
We introduce the notion of Spanier-Whitehead $K$-duality for a discrete group $G$, defined as duality in the KK-category between two $C*$-algebras which are naturally attached to the group, namely the reduced group ...
• #### On Co-Minimal Pairs in Abelian Groups ﻿

[OWP-2019-19] (Mathematisches Forschungsinstitut Oberwolfach, 2019-07-09)
A pair of non-empty subsets $(W,W')$ in an abelian group $G$ is a complement pair if $W+W'=G$. $W'$ is said to be minimal to $W$ if $W+(W'\setminus \{w'\}) \neq G, \forall \,w'\in W'$. In general, given an arbitrary subset ...