Language:   Search:   Contact
Zentralblatt MATH has released its new interface!
For an improved author identification, see the new author database of ZBMATH.

Query:
Fill in the form and click »Search«...
Format:
Display: entries per page entries
Zbl 1241.15002
Ball, Simeon
On sets of vectors of a finite vector space in which every subset of basis size is a basis.
(English)
[J] J. Eur. Math. Soc. (JEMS) 14, No. 3, 733-748 (2012). ISSN 1435-9855; ISSN 1435-9863/e

Summary: It is shown that the maximum size of a set ${ S}$ of vectors of a $k$-dimensional vector space over ${\mathbb F}_q$, with the property that every subset of size $k$ is a basis, is at most $q+1$, if $k \leq p$, and at most $q+k-p$, if $q \geq k \geq p+1 \geq 4$, where $q=p^h$ and $p$ is prime. Moreover, for $k\leq p$, the sets $S$ of maximum size are classified, generalising Beniamino Segre's arc is a conic'' theorem. These results have various implications. One such implication is that a $k\times (p+2)$ matrix, with $k \leq p$ and entries from ${\mathbb F}_p$, has $k$ columns which are linearly dependent. Another is that the uniform matroid of rank $r$ that has a base set of size $n \geq r+2$ is representable over ${\mathbb F}_p$ if and only if $n \leq p+1$. It also implies that the main conjecture for maximum distance separable codes is true for prime fields; that there are no maximum distance separable linear codes over ${\mathbb F}_p$, of dimension at most $p$, longer than the longest Reed-Solomon codes. The classification implies that the longest maximum distance separable linear codes, whose dimension is bounded above by the characteristic of the field, are Reed-Solomon codes.
MSC 2000:
*15A03 Vector spaces
05B35 Matroids (combinatorics)
51E21 Blocking sets, ovals, k-arcs
94B05 General theory of linear codes

Keywords: arcs; maximum distance separable codes; uniform matroids; vector space; basis; rank; Reed-Solomon codes

Cited in: Zbl 1257.51006

Highlights
Master Server