Approximations for Fault-Tolerant Total and Partial Positive Influence Domination

TL;DR

This paper introduces approximation algorithms for fault-tolerant total domination and related influence domination problems in graphs, providing the first logarithmic approximation bounds for these complex variants.

Contribution

It presents the first approximation algorithms with logarithmic bounds for fault-tolerant total domination and weighted partial positive influence dominating set problems.

Findings

First $1 + abla(\Delta + m - 1)$ approximation for fault-tolerant total domination.

Logarithmic approximations for simple, total, and connected influence domination variants.

Extended approximation framework for non-submodular functions to fractional values.

Abstract

In $\textit{total domination}$, given a graph $G=(V,E)$, we seek a minimum-size set of nodes $S\subseteq V$, such that every node in $V$ has at least one neighbor in $S$. We define a $\textit{fault-tolerant}$ version of total domination, where we require any node in $V \setminus S$ to have at least $m$ neighbors in $S$. Let $\Delta$ denote the maximum degree in $G$. We prove a first $1 + \ln(\Delta + m - 1)$ approximation for fault-tolerant total domination. We also consider fault-tolerant variants of the weighted $\textit{partial positive influence dominating set}$ problem, where we seek a minimum-size set of nodes $S\subseteq V$, such that every node in $V$ is either a member of $S$ or the sum of weights of its incident edges leading to nodes in $S$ is at least half of the sum of weights over all its incident edges. We prove the first logarithmic approximations for the simple, total, and connected variants of this problem. To prove the result for the connected case, we extend the general approximation framework for non-submodular functions from integer-valued to fractional-valued functions, which we believe is of independent interest.