Graphes de Ramanujan et applications
For each global field of positive characteristic we exhibit many examples of two-variable algebraic functions possessing properties consistent with a conjectural refinement of the Stark conjecture in the function field case recently proposed by the author. All the examples are Coleman units. We obtain our results by studying rank one shtukas in which both zero and pole are generic, i. e., shtukas not associated to any Drinfeld module.
We study sums and products in a field. Let be a field with , where is the characteristic of . For any integer , we show that any can be written as with and , and that for any we can write every as with and . We also prove that for any and there are such that .
In the present paper we investigate distributional properties of sparse sequences modulo almost all prime numbers. We obtain new results for a wide class of sparse sequences which in particular find applications on additive problems and the discrete Littlewood problem related to lower bound estimates of the -norm of trigonometric sums.