18 research outputs found
The order of the automorphism group of a binary -analog of the Fano plane is at most two
It is shown that the automorphism group of a binary -analog of the Fano
plane is either trivial or of order .Comment: 10 page
Matroids with nine elements
We describe the computation of a catalogue containing all matroids with up to
nine elements, and present some fundamental data arising from this cataogue.
Our computation confirms and extends the results obtained in the 1960s by
Blackburn, Crapo and Higgs. The matroids and associated data are stored in an
online database, and we give three short examples of the use of this database.Comment: 22 page
Nonexistence Certificates for Ovals in a Projective Plane of Order Ten
In 1983, a computer search was performed for ovals in a projective plane of
order ten. The search was exhaustive and negative, implying that such ovals do
not exist. However, no nonexistence certificates were produced by this search,
and to the best of our knowledge the search has never been independently
verified. In this paper, we rerun the search for ovals in a projective plane of
order ten and produce a collection of nonexistence certificates that, when
taken together, imply that such ovals do not exist. Our search program uses the
cube-and-conquer paradigm from the field of satisfiability (SAT) checking,
coupled with a programmatic SAT solver and the nauty symbolic computation
library for removing symmetries from the search.Comment: Appears in the Proceedings of the 31st International Workshop on
Combinatorial Algorithms (IWOCA 2020
LinCode - computer classification of linear codes
We present an algorithm for the classification of linear codes over finite
fields, based on lattice point enumeration. We validate a correct
implementation of our algorithm with known classification results from the
literature, which we partially extend to larger ranges of parameters.Comment: 12 pages, 5 table
Maximal integral point sets in affine planes over finite fields
Motivated by integral point sets in the Euclidean plane, we consider integral
point sets in affine planes over finite fields. An integral point set is a set
of points in the affine plane over a finite field
, where the formally defined squared Euclidean distance of every
pair of points is a square in . It turns out that integral point
sets over can also be characterized as affine point sets
determining certain prescribed directions, which gives a relation to the work
of Blokhuis. Furthermore, in one important sub-case integral point sets can be
restated as cliques in Paley graphs of square order. In this article we give
new results on the automorphisms of integral point sets and classify maximal
integral point sets over for . Furthermore, we give two
series of maximal integral point sets and prove their maximality.Comment: 18 pages, 3 figures, 2 table
Computer classification of linear codes
We present algorithms for classification of linear codes over finite fields,
based on canonical augmentation and on lattice point enumeration. We apply
these algorithms to obtain classification results over fields with 2, 3 and 4
elements. We validate a correct implementation of the algorithms with known
classification results from the literature, which we partially extend to larger
ranges of parameters.Comment: 18 pages, 9 tables; this paper is a merge and extension of
arXiv:1907.10363 and arXiv:1912.0935