Ana Silva

activity

20172020

collaborators

5 papers

math.CO2020

Cycle convexity and the tunnel number of links

Júlio Araújo, Victor Campos, Darlan Girão +3

In this work, we introduce a new graph convexity, that we call Cycle Convexity, motivated by related notions in Knot Theory. For a graph $G = (V, E)$ , define the interval function in…

cs.CC2020

On the proper orientation number of chordal graphs

Julio Araujo, Alexandre Cezar, Carlos V. G. C. Lima +2

An orientation $D$ of a graph $G = (V, E)$ is a digraph obtained from $G$ by replacing each edge by exactly one of the two possible arcs with the same end vertices. For each $v \in V(…

cs.DS2018

Dual parameterization of Weighted Coloring

Júlio Araújo, Victor A. Campos, Carlos Vinícius G. C. Lima +3

Given a graph $G$ , a proper $k$ -coloring of $G$ is a partition $c = (S_{i})_{i \in [1, k]}$ of $V (G)$ into $k$ stable sets $S_{1}, \dots, S_{k}$ . Given a weight function $w: V(G) \to \ma…

cs.DS2018

Weighted proper orientations of trees and graphs of bounded treewidth

Júlio Araújo, Cláudia Linhares Sales, Ignasi Sau +1

Given a simple graph $G$ , a weight function $w : E (G) \to N ∖ {0}$ , and an orientation $D$ of $G$ , we define $μ^{-} (D) = max_{v \in V (G)} w_{D}^{-} (v)$ , where $w…

cs.DS2017

On the complexity of finding internally vertex-disjoint long directed paths

Júlio Araújo, Victor A. Campos, Ana Karolinna Maia +2

For two positive integers $k$ and $ℓ$ , a $(k \times ℓ)$ -spindle is the union of $k$ pairwise internally vertex-disjoint directed paths with $ℓ$ arcs between two vertices $…