TY - JOUR
T1 - Polar graphs and corresponding involution sets, loops and Steiner triple systems
AU - Karzel, Helmut
AU - Pianta, Silvia
AU - Zizioli, Elena
PY - 2006
Y1 - 2006
N2 - A 1-factorization (or parallelism) of the complete graph with loops
(P, E, ) is called polar if each 1-factor (parallel class) contains exactly one
loop and for any three distinct vertices x1, x2, x3, if {x1} and {x2, x3} belong
to a 1-factor then the same holds for any permutation of the set {1, 2, 3}.
To a polar graph (P, E,|| ) there corresponds a polar involution set (P, I), an
idempotent totally symmetric quasigroup (P, ∗), a commutative, weak inverse
property loop (P,+) of exponent 3 and a Steiner triple system (P, B).
We have: (P, E,|| ) satisfies the trapezium axiom ⇔ ∀α ∈ I : αIα =
I ⇔(P, ∗) is self-distributive ⇔ (P,+) is a Moufang loop ⇔ (P, B) is an affine
triple system; and: (P, E,|| ) satisfies the quadrangle axiom⇔ I3 =I ⇔(P, +)
is a group ⇔ (P, B) is an affine space.
AB - A 1-factorization (or parallelism) of the complete graph with loops
(P, E, ) is called polar if each 1-factor (parallel class) contains exactly one
loop and for any three distinct vertices x1, x2, x3, if {x1} and {x2, x3} belong
to a 1-factor then the same holds for any permutation of the set {1, 2, 3}.
To a polar graph (P, E,|| ) there corresponds a polar involution set (P, I), an
idempotent totally symmetric quasigroup (P, ∗), a commutative, weak inverse
property loop (P,+) of exponent 3 and a Steiner triple system (P, B).
We have: (P, E,|| ) satisfies the trapezium axiom ⇔ ∀α ∈ I : αIα =
I ⇔(P, ∗) is self-distributive ⇔ (P,+) is a Moufang loop ⇔ (P, B) is an affine
triple system; and: (P, E,|| ) satisfies the quadrangle axiom⇔ I3 =I ⇔(P, +)
is a group ⇔ (P, B) is an affine space.
KW - graphs
KW - loops
KW - steiner systems
KW - graphs
KW - loops
KW - steiner systems
UR - http://hdl.handle.net/10807/55454
U2 - 10.1007/s00025-006-0214-4
DO - 10.1007/s00025-006-0214-4
M3 - Article
SN - 1422-6383
SP - 149
EP - 160
JO - Results in Mathematics
JF - Results in Mathematics
ER -