A period is a complex number arising as the integral of a rational function
with algebraic number coefficients over a rationally-defined region. Although
periods are typically transcendental numbers, there is a conjectural Galois
theory of periods coming from the theory of motives. This paper formalizes an
analogy between a class of periods called multiple zeta values, and congruences
for rational numbers modulo prime powers (called supercongruences). We
construct an analogue of the motivic period map in the setting of
supercongruences, and use it to define a Galois theory of supercongruences. We
describe an algorithm using our period map to find and prove supercongruences,
and we provide software implementing the algorithm.Comment: 24 pages. Comments are welcome. Most of the results of this paper
were previously part of arXiv:1608.0686