Povzetek

Let ▫$\Gamma$▫ denote a ▫$Q$▫-polynomial distance-regular graph with diameter ▫$D \ge 3$▫ and intersection numbers ▫$a_1=0$▫, ▫$a_2 \ne 0$▫. Let ▫$X$▫ denote the vertex set of ▫$\Gamma$▫ and let ▫$A \in {\mathrm{Mat}}_X ({\mathbb{C}})$▫ denote the adjacency matrix of ▫$\Gamma$▫. Fix ▫$x \in X$▫ and let denote $A^\ast \in {\mathrm{Mat}}_X ({\mathbb{C}})$ the corresponding dual adjacency matrix. Let ▫$T$▫ denote the subalgebra of ▫$A{\mathrm{Mat}}_X ({\mathbb{C}})$▫ generated by ▫$A$▫, ▫$A^\ast$▫. We call ▫$T$▫ the Terwilliger algebra of ▫$\Gamma$▫ with respect to ▫$x$▫. We show that up to isomorphism there exists a unique irreducible ▫$T$▫-module ▫$W$▫ with endpoint 1. We show that ▫$W$▫ has dimension ▫$2D-2$▫. We display a basis for ▫$W$▫ which consists of eigenvectors for ▫$A^\ast$▫. We display the action of ▫$A$▫ on this basis. We show that ▫$W$▫ appears in the standard module of ▫$\Gamma$▫ with multiplicity ▫$k-1$▫, where ▫$k$▫ is the valency of ▫$\Gamma$▫.

Ključne besede

matematika;teorija grafov;razdaljno regularni grafi;matrika sosednosti;Terwilligerjeva algebra;mathematics;graph theory;adjacency matrix;distance-regular graph;Terwilliger algebra;

Podatki

Jezik: Angleški jezik
Leto izida:
Tipologija: 1.01 - Izvirni znanstveni članek
Organizacija: UP - Univerza na Primorskem
UDK: 519.17
COBISS: 14627929 Povezava se bo odprla v novem oknu
ISSN: 0195-6698
Št. ogledov: 4075
Št. prenosov: 30
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Sekundarni jezik: Angleški jezik
Sekundarne ključne besede: matematika;teorija grafov;razdaljno regularni grafi;matrika sosednosti;Terwilligerjeva algebra;
Vrsta dela (COBISS): Delo ni kategorizirano
Strani: str. 192-207
Letnik: ǂVol. ǂ30
Zvezek: ǂno. ǂ1
Čas izdaje: 2009
DOI: 10.1016/j.ejc.2008.02.001
ID: 1473516