Ginsparg's theorem

Ginsparg's theorem addresses how certain symmetries, like chiral symmetry, behave when space-time is discretized into a grid (lattice) for calculations in quantum field theory. It states that a modified version of these symmetries can be preserved exactly on the lattice, even though the original symmetry is broken by the discretization. This allows physicists to study important properties of particles, such as their masses and interactions, using computational methods without losing key features of the underlying theory. Essentially, Ginsparg's theorem ensures a consistent way to approximate continuous physical laws on a discrete computational grid.