Heawood proved that every planar graph with no 1-cycles is vertex 5colorable, which is equivalent to the statement that every planar graph with no 1-bonds has a nowhere-zero 5-flow. Tutte has conjectured that every graph with no 1-bonds has a nowhere-zero 5-flow. We show that Tutte's 5-Flow Conjectu
The Tutte group of projective planes
β Scribed by Franz Kalhoff
- Publisher
- Springer
- Year
- 1992
- Tongue
- English
- Weight
- 312 KB
- Volume
- 43
- Category
- Article
- ISSN
- 0046-5755
No coin nor oath required. For personal study only.
β¦ Synopsis
Dress and Wenzel have codified the notion of the Tutte group of a matroid and have determined the Tutte group of projective spaces over skew fields and of finite projective planes. In this note we shall examine the Tutte group of arbitrary projective planes.
Let H = (~, A '~) be a projective plane not of order 2. Considering H as a matroid, its extended Tutte group is given by T jr := U:~r/K~e, where F ~e is the free abelian group generated by all antiflags (L, p) ~ ~ Γ ~ and by a special element e, and ~e equals the subgroup of ~:Je generated by e 2 and by all elements of the shape n(A, bXA, c)-I(B, cXB, a)-1(C, aXC, b) -1 with mutually distinct, confluent lines A, B, C and points aEA\B, beB\C, c E C\A. We denote the elements of T ~e by
π SIMILAR VOLUMES
In the present article we shall show that any two disjoint Baer subplanes of PG(2,q 2) are contained in exactly one Singer-Baer partition. Given two disjoint Baer subplanes of P = PG(2,q 2) with Baer involutions zo and zi we shall see that 6 := zozl is a projective collineation whose order is a div
Compact connected projective planes have been investigated extensively in the last 30 years, mostly by studying their automorphism groups. It is our aim here to remove the connectedness assumption in some general results of Salzmann [31] and H/ihl[14] on automorphism groups of compact projective pla