Akademska digitalna zbirka SLovenije - logo
Narodna in univerzitetna knjižnica, Ljubljana (NUK)
Naročanje gradiva za izposojo na dom
Naročanje gradiva za izposojo v čitalnice
Naročanje kopij člankov
Urnik dostave gradiva z oznako DS v signaturi
  • Highly arc-transitive digraphs with no homomorphism onto Z
    Malnič, Aleksander ...
    If an infinite digraph ▫$D$▫ an edge ▫$e'$▫ is reachable from an edge ▫$e$▫ if there exist an alternating walk in ▫$D$▫ whose initial and terminal edges are ▫$e$▫ and ▫$e'$▫. Reachability is an ... equivalence relation and if ▫$D$▫ is 1-arc-transitive, then this relation is either universal or all of its equivalence classes induce isomorphic bipartite digraphs. In earlier paper Cameron, Praeger and Wormald asked if there exist highly arc-transitive digraphs (apart from directed cycles) for which the reachability relation is not universal and which do not have a homomorphism onto the two-way infinite directed path (a Cayley diagraph of ▫$\mathbb Z$▫ with respect to one generator. Evans gave an affirmative answer by constructing a locally infinite example. For each odd integer ▫$n \ge 3$▫, a construction of a highly arc-transitive digraph without property ▫$Z$▫ satisfying the additional properties that its in- and out-degrees are equal to 2 and that the reahability equivalence classes induce alternating cycles of length ▫$2n$▫, is given. Futhermore, using the line digraph operator, digraphs having the above properties but with alternating cycles of length 4 are obtained.
    Vir: Preprint series. - ISSN 1318-4865 (Vol. 37, [št.] 659, 1999, str. 1-10)
    Vrsta gradiva - članek, sestavni del
    Leto - 1999
    Jezik - angleški
    COBISS.SI-ID - 8888921

vir: Preprint series. - ISSN 1318-4865 (Vol. 37, [št.] 659, 1999, str. 1-10)

loading ...
loading ...
loading ...

Vnos na polico