turkmath.org

In this seminar I will talk about the connection between the limiting distributions of rational points on horocycle flows and the value distribution of incomplete Gauss sums. A key property of the horocycle flow on a finite-area hyperbolic surface is that long closed horocycles are uniformly distributed. We embed rational points on such horocycles on the modular surface and investigate their equidistribution properties. On the other hand, it is well known that the classical Gauss sums can be evaluated in closed form depending on the residue class of the number of terms in the sum modulo 4. This is not the case for the incomplete Gauss sums, where we restrict the range of summation to a sub-interval and study their limiting behavior at random argument as the number of terms goes to infinity. If the time permits, I also establish an analogue of the weak invariance principle for incomplete Gauss sums.