Arkhipov's theorem, graph minors, and linear system nonlocal games

Abstract

The perfect quantum strategies of a linear system game correspond to certain representations of its solution group. We study the solution groups of graph incidence games, which are linear system games in which the underlying linear system is the incidence system of a (non-properly) twocoloured graph. While it is undecidable to determine whether a general linear system game has a perfect quantum strategy, for graph incidence games this problem is solved by Arkhipov's theorem, which states that the graph incidence game of a connected graph has a perfect quantum strategy if and only if it either has a perfect classical strategy, or the graph is nonplanar. Arkhipov's criterion can be rephrased as a forbidden minor condition on connected twocoloured graphs. We extend Arkhipov's theorem by showing that, for graph incidence games of connected two-coloured graphs, every quotient closed property of the solution group has a forbidden minor characterization. We rederive Arkhipov's theorem from the group theoretic point of view, and then find the forbidden minors for two new properties: finiteness and abelianness. Our methods are entirely combinatorial, and finding the forbidden minors for other quotient closed properties seems to be an interesting combinatorial problem. the most restrictive model of finite-dimensional strategies. Commuting-operator strategies refers to the most permissive model of infinite-dimensional strategies.

Simplicial techniques for operator solutions of linear constraint systems

“…together with the function b specifies a linear system. Note that Σ A(K) coincides with the dual complex K. For more on these kinds of linear systems see [PRSS22]. Each triangle is assigned a value b i (pink color corresponds to 1 value).…”