Zobrazeno 1 - 10
of 58
pro vyhledávání: '"van Zwam, Stefan H. M."'
Publikováno v:
SIAM Journal on Discrete Mathematics 35 (2021), 1356-1380
Subject to announced results by Geelen, Gerards, and Whittle, we completely characterize the highly connected members of the classes of dyadic, near-regular, and sixth-root-of-unity matroids.
Comment: In Version 3, improvements have been made to
Comment: In Version 3, improvements have been made to
Externí odkaz:
http://arxiv.org/abs/1903.04910
Autor:
Grace, Kevin, van Zwam, Stefan H. M.
Publikováno v:
Annals of Combinatorics 22 (2018), 513-542
Geelen, Gerards, and Whittle [3] announced the following result: let $q = p^k$ be a prime power, and let $\mathcal{M}$ be a proper minor-closed class of $\mathrm{GF}(q)$-representable matroids, which does not contain $\mathrm{PG}(r-1,p)$ for sufficie
Externí odkaz:
http://arxiv.org/abs/1712.07702
We consider the GF$(4)$-representable matroids with a circuit-hyperplane such that the matroid obtained by relaxing the circuit-hyperplane is also GF$(4)$-representable. We characterize the structure of these matroids as an application of structure t
Externí odkaz:
http://arxiv.org/abs/1704.07306
Autor:
Grace, Kevin, van Zwam, Stefan H. M.
Publikováno v:
SIAM Journal on Discrete Mathematics 33 (2019), 26-67
The classes of even-cycle matroids, even-cycle matroids with a blocking pair, and even-cut matroids each have hundreds of excluded minors. We show that the number of excluded minors for these classes can be drastically reduced if we consider in each
Externí odkaz:
http://arxiv.org/abs/1610.01106
Autor:
Grace, Kevin, van Zwam, Stefan H. M.
Publikováno v:
SIAM Journal on Discrete Mathematics 31 (2017), 254-282
A binary frame template is a device for creating binary matroids from graphic or cographic matroids. Such matroids are said to conform or coconform to the template. We introduce a preorder on these templates and determine the nontrivial templates tha
Externí odkaz:
http://arxiv.org/abs/1605.08098
Autor:
Nelson, Peter, van Zwam, Stefan H. M.
For a class $\mathcal{C}$ of binary linear codes, we write $\theta_{\mathcal{C}}\colon (0,1) \to [0,\frac{1}{2}]$ for the maximum-likelihood decoding threshold function of $\mathcal{C}$, the function whose value at $R \in (0,1)$ is the largest bit-er
Externí odkaz:
http://arxiv.org/abs/1504.05225
Autor:
Nelson, Peter, van Zwam, Stefan H. M.
Let $\mathcal{C} = (C_1, C_2, \ldots)$ be a sequence of codes such that each $C_i$ is a linear $[n_i,k_i,d_i]$-code over some fixed finite field $\mathbb{F}$, where $n_i$ is the length of the codewords, $k_i$ is the dimension, and $d_i$ is the minimu
Externí odkaz:
http://arxiv.org/abs/1404.7771
Autor:
Nelson, Peter, van Zwam, Stefan H. M.
A matroid is $\text{GF}(q)$-regular if it is representable over all proper superfields of the field $\text{GF}(q)$. We show that, for highly connected matroids having a large projective geometry over $\text{GF}(q)$ as a minor, the property of $\text{
Externí odkaz:
http://arxiv.org/abs/1401.7040
If S is a set of matroids, then the matroid M is S-fragile if, for every element e in E(M), either M\e or M/e has no minor isomorphic to a member of S. Excluded-minor characterizations often depend, implicitly or explicitly, on understanding classes
Externí odkaz:
http://arxiv.org/abs/1312.5401
Autor:
Chun, Carolyn, Chun, Deborah, Clark, Benjamin, Mayhew, Dillon, Whittle, Geoff, van Zwam, Stefan H. M.
This technical report accompanies the following three papers. It contains the computations necessary to verify some of the results claimed in those papers. [1] Carolyn Chun, Deborah Chun, Dillon Mayhew, and Stefan H. M. van Zwam. Fan-extensions in fr
Externí odkaz:
http://arxiv.org/abs/1312.5175