Let G be a graph class. The square root of G contains all graphs whose square belong in G. We prove that if G is non-trivial and minor closed, then all graphs in its square root have carving-width bounded by some constant depending only on G. As a consequence, every square root of such a graph class has a linear time recognition algorithm.

We define the limiting density of a minor-closed family of simple graphs F to be the smallest number k such that every n-vertex graph in F has at most kn(1+o(1)) edges, and we investigate the set of numbers that can be limiting densities. This set of numbers is countable, well-ordered, and closed; its order type is at least ωω. It is the closure of the set of densities of density-minimal graphs...

We give a common generalisation of the closed graph theorems of De Wilde and of Popa.

The aim of this paper is that of discussing closed graph theorems for bornological vector spaces in a self-contained way, hoping to make the subject more accessible to non-experts. We will see how to easily adapt classical arguments of functional analysis over R and C to deduce closed graph theorems for bornological vector spaces over any complete, non-trivially valued field, hence encompassing...

In this paper we shall establish some forms of the closed, graph theorem for locally convex spaces, using the approach of Ptak(l7). Our interest is in classifying pairs of locally convex spaces (E, F) which have the property that every closed graph linear mapping T: E -> F is continuous; if (E,F) has this property then we shall say that (E, F) is in the class *&. \is# is a particular class of l...

This paper adresses the following problem: Given a closed orientable threemanifold M , are there at most finitely many closed orientable three-manifolds 1-dominated by M? We solve this question for the class of closed orientable graph manifolds. More presisely the main result of this paper asserts that any closed orientable graph manifold 1dominates at most finitely many orientable closed three...

Article history: Received 2 October 2010 Accepted 25 May 2011 Available online 19 July 2011 Communicated by Paul Helm

Let $kgeq 1$ be an integer, and $G=(V,E)$ be a finite and simplegraph. The closed neighborhood $N_G[e]$ of an edge $e$ in a graph$G$ is the set consisting of $e$ and all edges having a commonend-vertex with $e$. A signed Roman edge $k$-dominating function(SREkDF) on a graph $G$ is a function $f:E rightarrow{-1,1,2}$ satisfying the conditions that (i) for every edge $e$of $G$, $sum _{xin N[e]} f...