Tau conjecture

In mathematics, the tau conjecture may refer to one of


 * Lehmer's conjecture on the non-vanishing of the Ramanujan tau function
 * The Ramanujan–Petersson conjecture on the rate of growth of the Ramanujan tau function, proved by Deligne
 * Shub and Smale's tau-conjecture on the integer zeroes of a polynomial, one of Smale's problems