An amazing coincidence of formulas for the unit root part of crystalline cohomology and the density of states for physical crystals

Certain Laurent polynomials can be viewed as discretizations of a Laplace operator with quasi-periodic boundary conditions. The eigenvalue/eigenfunction equation for this situation then describes the level sets of the Laurent polynomial. The density of states is a measure for the size of these level sets as a function of the level. It can be approximated, in yet another discretization, by counting how the points of which the coordinates are N-th roots of 1 are distributed over the various level sets. The limit as N tends to infinity is also known in number theory/algebraic geometry as the Mahler measure of the Laurent polynomial. By a simple transformation which is reminiscent of the Mellin transform the formula for the density of states becomes a formula for the formal group which describes the unit root part of the crystalline cohomology of the level sets which are then viewed as hypersurfaces in a toric variety. For real solid state physics the Laurent polynomial has to be replaced by a matrix (i.e. an endomorphism of a vector bundle) over a toric variety.