TY - JOUR
T1 - Topological graph inverse semigroups
AU - Mesyan, Z.
AU - Mitchell, J. D.
AU - Morayne, M.
AU - Péresse, Y. H.
N1 - Michał Morayne was partially supported by NCN grant DEC-2011/01/B/ST1/01439 while this work was performed.
PY - 2016/8/1
Y1 - 2016/8/1
N2 - To every directed graph E one can associate a graph inverse semigroup G(E), where elements roughly correspond to possible paths in E . These semigroups generalize polycyclic monoids, and they arise in the study of Leavitt path algebras, Cohn path algebras, graph C⁎C⁎-algebras, and Toeplitz C⁎-algebras. We investigate topologies that turn G(E) into a topological semigroup. For instance, we show that in any such topology that is Hausdorff, G(E)∖{0} must be discrete for any directed graph E . On the other hand, G(E) need not be discrete in a Hausdorff semigroup topology, and for certain graphs E , G(E) admits a T1 semigroup topology in which G(E)∖{0} is not discrete. We also describe, in various situations, the algebraic structure and possible cardinality of the closure of G(E) in larger topological semigroups.
AB - To every directed graph E one can associate a graph inverse semigroup G(E), where elements roughly correspond to possible paths in E . These semigroups generalize polycyclic monoids, and they arise in the study of Leavitt path algebras, Cohn path algebras, graph C⁎C⁎-algebras, and Toeplitz C⁎-algebras. We investigate topologies that turn G(E) into a topological semigroup. For instance, we show that in any such topology that is Hausdorff, G(E)∖{0} must be discrete for any directed graph E . On the other hand, G(E) need not be discrete in a Hausdorff semigroup topology, and for certain graphs E , G(E) admits a T1 semigroup topology in which G(E)∖{0} is not discrete. We also describe, in various situations, the algebraic structure and possible cardinality of the closure of G(E) in larger topological semigroups.
KW - Graph inverse semigroup
KW - Polycyclic monoid
KW - Topological semigroup
UR - http://arxiv.org/abs/1306.5388
U2 - 10.1016/j.topol.2016.05.012
DO - 10.1016/j.topol.2016.05.012
M3 - Article
SN - 0166-8641
VL - 208
SP - 106
EP - 126
JO - Topology and Its Applications
JF - Topology and Its Applications
ER -