On a dynamical Brauer–Manin obstruction
Let be a morphism of a variety defined over a number field , let be a -subvariety, and let be the orbit of a point . We describe a local-global principle for the intersection . This principle may be viewed as a dynamical analog of the Brauer–Manin obstruction. We show that the rational points of are Brauer–Manin unobstructed for power maps on in two cases: (1) is a translate of a torus. (2) is a line and has a preperiodic coordinate. A key tool in the proofs is the classical...