Zobrazeno 1 - 10
of 142
pro vyhledávání: '"Meshulam, Roy"'
Autor:
Meshulam, Roy, Moyal, Omer
Let $\mathbb{S}_n$ denote the symmetric group on $[n]=\{1,\ldots,n\}$ with the uniform probability measure. For a permutation $\pi \in \mathbb{S}_n$ let $X_{\pi}$ denote the simplicial complex on the vertex set $[n]$ whose simplices are all $\{i_0,\l
Externí odkaz:
http://arxiv.org/abs/2406.19022
Publikováno v:
Israel Journal of Mathematics 256.1 (2023): 297-309
In this note we prove two extensions of a recent combinatorial characterization due to Li, Qiao, Wigderson, Wigderson and Zhang (arXiv:2206.04815) of the maximal dimension of bounded rank subspaces of the graphical matrix space associated with a bipa
Externí odkaz:
http://arxiv.org/abs/2212.11193
Autor:
Meshulam, Roy
Let $G$ be a finite group of order $n$ and for $1 \leq i \leq k+1$ let $V_i=\{i\} \times G$. Viewing each $V_i$ as a $0$-dimensional complex, let $Y_{G,k}$ denote the simplicial join $V_1*\cdots*V_{k+1}$. For $A \subset G$ let $Y_{A,k}$ be the subcom
Externí odkaz:
http://arxiv.org/abs/2211.02085
Autor:
Kalai, Gil, Meshulam, Roy
Let $\mathbb{F}$ be a fixed field and let $X$ be a simplicial complex on the vertex set $V$. The Leray number $L(X;\mathbb{F})$ is the minimal $d$ such that for all $i \geq d$ and $S \subset V$, the induced complex $X[S]$ satisfies $\tilde{H}_i(X[S];
Externí odkaz:
http://arxiv.org/abs/2002.06630
We show that the size of the largest simple d-cycle in a simplicial d-complex $K$ is at least a square root of $K$'s density. This generalizes a well-known classical result of Erd\H{o}s and Gallai \cite{EG59} for graphs. We use methods from matroid t
Externí odkaz:
http://arxiv.org/abs/1910.04605
Autor:
Dinur, Irit, Meshulam, Roy
We study the stability of covers of simplicial complexes. Given a map $f:Y\to X$ that satisfies almost all of the local conditions of being a cover, is it close to being a genuine cover of $X$? Complexes $X$ for which this holds are called cover-stab
Externí odkaz:
http://arxiv.org/abs/1909.08507
An injective word over a finite alphabet $V$ is a sequence $w=v_1v_2\cdots v_t$ of distinct elements of $V$. The set $\mathrm{inj}(V)$ of injective words on $V$ is partially ordered by inclusion. A complex of injective words is the order complex $\De
Externí odkaz:
http://arxiv.org/abs/1908.03394
Autor:
Meshulam, Roy, Zerbib, Shira
Let $V$ be an $n$-dimensional vector space over the finite field of order $q$. The spherical building $X_V$ associated with $GL(V)$ is the order complex of the nontrivial linear subspaces of $V$. Let $\mathfrak{g}$ be the local coefficient system on
Externí odkaz:
http://arxiv.org/abs/1807.05297
Autor:
Meshulam, Roy
It is shown that the good expander codes introduced by Sipser and Spielman, can be realized as the first homology of a graph with respect to a certain twisted coefficient system.
Comment: 4 pages
Comment: 4 pages
Externí odkaz:
http://arxiv.org/abs/1803.05643
Autor:
Kozlov, Dmitry N., Meshulam, Roy
We study several aspects of the $k$-th Cheeger constant of a complex X, a parameter that quantifies the distance of $X$ from a complex $Y$ with nontrivial $k$-th cohomology over $\mathbb{Z}_2$. Our results include general methods for bounding the cos
Externí odkaz:
http://arxiv.org/abs/1802.03210