Year: 2025
Type: preprint
Abstract: By an independent set in a simple graph $G$, we mean a set of pairwise non-adjacent vertices in $G$. The independence polynomial of $G$ is defined as $I_G(z)=a_0 + a_1 z + a_2 z^2+\cdots+a_αz^α$, where $a_i$ is the number of independent sets in $G$ with cardinality $i$ and $α$ is the cardinality of a largest independent set in $G$, known as the independence number of $G$. Let $G^m$ denote the $m$-times lexicographic product of $G$ with itself. The independence attractor of $G$, denoted by $\mathcal{A}(G)$, is defined as $\mathcal{A}(G) = \lim_{m\rightarrow \infty} \{z: I_{G^m}(z)=0\}$, where the limit is taken with respect to the Hausdorff metric on the space of all compact subsets of the plane. This paper deals with independence attractors that are topologically simple. It is shown that $\mathcal{A}(G)$ can never be a circle. If $\mathcal{A}(G)$ is a line segment then it is proved that the line segment is $[-\frac{4}{k}, 0]$ for some $k \in \{1, 2, 3, 4 \}$. Examples of graphs with independence number four are provided whose independence attractors are line segments.
Source: arXiv (Cornell University)
Authors: Khetawat, Garima, Manna, Moumita, Nayak, Tarakanta
Institution: Indian Institute of Technology Bhubaneswar
Language: English
Subfield: Geometry and Topology
Field: Mathematics
Domain: Physical Sciences
Open Access status: green
Funder: University Grants Commission
OpenAlex ID: W4415036458
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