Mathematicians find hidden patterns in graph theory with real-world applications
Researchers have solved a decades-old puzzle about how networks organize themselves, discovering that the answer depends entirely on the network's structure. The findings could help companies optimize everything from supply chains to social networks by predicting how interconnected systems behave.
Originaltitel: The minimum number of maximal independent sets in twin-free graphs
<p>The problem of determining the maximum number of maximal independent sets in certain graph classes dates back to a paper of Miller and Muller and a question of Erdos and Moser from the 1960s. The minimum was always considered to be less interesting due to simple examples such as stars. In this paper we show that the problem becomes interesting when restricted to twin-free graphs, where no two vertices have the same open neighbourhood. We consider the question for arbitrary graphs, bipartite graphs and trees. The minimum number of maximal independent sets turns out to be logarithmic in the number of vertices for arbitrary graphs, linear for bipartite graphs and exponential for trees. In the latter case, the minimum and the extremal graphs have been determined earlier by Taletskiii and Malyshev, but we present a shorter proof.</p>