Quantum mechanics of bipartite ribbon graphs: Integrality, Lattices and Kronecker coefficients

TL;DR

This paper introduces a quantum mechanical framework based on bipartite ribbon graphs, revealing new insights into Kronecker coefficients, lattice structures, and their implications for quantum complexity and geometric interpretations.

Contribution

It establishes a novel quantum system on ribbon graphs, linking algebraic, combinatorial, and geometric aspects, and provides a combinatorial interpretation of Kronecker coefficients.

Findings

Kronecker coefficients relate to lattice dimensions.

Quantum systems can be characterized by ribbon graph reconnection coefficients.

Potential for quantum experiments to explore Kronecker coefficients.

Abstract

We define solvable quantum mechanical systems on a Hilbert space spanned by bipartite ribbon graphs with a fixed number of edges. The Hilbert space is also an associative algebra, where the product is derived from permutation group products. The existence and structure of this Hilbert space algebra has a number of consequences. The algebra product, which can be expressed in terms of integer ribbon graph reconnection coefficients, is used to define solvable Hamiltonians with eigenvalues expressed in terms of normalized characters of symmetric group elements and degeneracies given in terms of Kronecker coefficients, which are tensor product multiplicities of symmetric group representations. The square of the Kronecker coefficient for a triple of Young diagrams is shown to be equal to the dimension of a sub-lattice in the lattice of ribbon graphs. This leads to an answer to the long-standing question of a combinatoric interpretation of the Kronecker coefficients. As an avenue to explore quantum supremacy and its implications for computational complexity theory, we outline experiments to detect non-vanishing Kronecker coefficients for hypothetical quantum realizations/simulations of these quantum systems. The correspondence between ribbon graphs and Belyi maps leads to an interpretation of these quantum mechanical systems in terms of quantum membrane world-volumes interpolating between string geometries.