Homology of graph burnings

In this paper we study graph burnings using methods of algebraic topology. We prove that the time function of a burning is a graph map to a path graph. We use this fact to define a category whose objects are graph burnings and morphisms are graph maps which commute with the time functions of the burnings. In this category we study relations between burnings of different graphs and, in particular, between burnings of a graph and its subgraphs. For every graph, we define a simplicial complex, arising from the set of all the burnings, which we call a configuration space of the burnings. The simplicial structure of the configuration space defines burning homology of the graph. We describe properties of the configuration space and the burning homology theory. We prove that the one-dimensional skeleton of the configuration space of a graph G coincides with the complement graph of G. The results are illustrated with numerous examples.