3 research outputs found
Greedy weights for matroids
We introduce greedy weights of matroids, inspired by those for linear codes.
We show that a Wei duality holds for two of these types of greedy weights for
matroids. Moreover we show that in the cases where the matroids involved are
associated to linear codes, our definitions coincide with those for codes. Thus
our Wei duality is a generalization of that for linear codes given by
Schaathun. In the last part of the paper we show how some important chains of
cycles of the matroids appearing, correspond to chains of component maps of
minimal resolutions of the independence complex of the corresponding matroids.
We also relate properties of these resolutions to chainedness and greedy
weights of the matroids, and in many cases codes, that appear.Comment: 17 page
Free Resolutions and Generalized Hamming Weights of binary linear codes
In this work, we explore the relationship between free resolution of some
monomial ideals and Generalized Hamming Weights (GHWs) of binary codes. More
precisely, we look for a structure smaller than the set of codewords of minimal
support that provides us some information about the GHWs. We prove that the
first and second generalized Hamming weight of a binary linear code can be
computed (by means of a graded free resolution) from a set of monomials
associated to a binomial ideal related with the code. Moreover, the remaining
weights are bounded by the Betti numbers for that set