Automorphisms of a distance-regular graph with intersection array {176, 135, 32, 1; 1, 16, 135, 176}
Trudy Instituta matematiki i mehaniki, Trudy Instituta Matematiki i Mekhaniki UrO RAN, Tome 24 (2018) no. 2, pp. 173-184

Voir la notice de l'article provenant de la source Math-Net.Ru

A distance-regular graph $\Gamma$ with intersection array $\{176,135,32,1;1,16,135,176\}$ is an $AT4$-graph. Its antipodal quotient $\bar\Gamma$ is a strongly regular graph with parameters $(672,176$, $40,48)$. In both graphs the neighborhoods of vertices are strongly regular with parameters $(176,40,12,8)$. We study the automorphisms of these graphs. In particular, the graph $\Gamma$ is not arc-transitive. If $G=\mathrm{Aut}\,(\Gamma)$ contains an element of order 11, acts transitively on the vertex set of $\Gamma$, and $S(G)$ fixes each antipodal class, then the full preimage of the group $(G/S(G))'$ is an extension of a group of order 3 by $M_{22}$ or $U_6(2)$. We describe automorphism groups of strongly regular graphs with parameters $(176,40,12,8)$ and $(672,176,40,48)$ in the vertex-symmetric case.
Keywords: strongly regular graph, distance-regular graph
Mots-clés : graph automorphism.
@article{TIMM_2018_24_2_a15,
     author = {A. A. Makhnev and D. V. Paduchikh},
     title = {Automorphisms of a distance-regular graph with intersection array {176, 135, 32, 1; 1, 16, 135, 176}},
     journal = {Trudy Instituta matematiki i mehaniki},
     pages = {173--184},
     publisher = {mathdoc},
     volume = {24},
     number = {2},
     year = {2018},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TIMM_2018_24_2_a15/}
}
TY  - JOUR
AU  - A. A. Makhnev
AU  - D. V. Paduchikh
TI  - Automorphisms of a distance-regular graph with intersection array {176, 135, 32, 1; 1, 16, 135, 176}
JO  - Trudy Instituta matematiki i mehaniki
PY  - 2018
SP  - 173
EP  - 184
VL  - 24
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/TIMM_2018_24_2_a15/
LA  - ru
ID  - TIMM_2018_24_2_a15
ER  - 
%0 Journal Article
%A A. A. Makhnev
%A D. V. Paduchikh
%T Automorphisms of a distance-regular graph with intersection array {176, 135, 32, 1; 1, 16, 135, 176}
%J Trudy Instituta matematiki i mehaniki
%D 2018
%P 173-184
%V 24
%N 2
%I mathdoc
%U http://geodesic.mathdoc.fr/item/TIMM_2018_24_2_a15/
%G ru
%F TIMM_2018_24_2_a15
A. A. Makhnev; D. V. Paduchikh. Automorphisms of a distance-regular graph with intersection array {176, 135, 32, 1; 1, 16, 135, 176}. Trudy Instituta matematiki i mehaniki, Trudy Instituta Matematiki i Mekhaniki UrO RAN, Tome 24 (2018) no. 2, pp. 173-184. http://geodesic.mathdoc.fr/item/TIMM_2018_24_2_a15/