Haifa University - Dept. of CS Theory Seminar Speaker : Zeev Dvir, Weizmann. Title: "Hardness-Randomness Tradeoffs for Bounded Depth Arithmetic Circuits". Date: Thursday, Mar. 13. Place: Haifa U. Education Building, room 570. Time: 12:15 - 13:30 Abstract: We show that lower bounds for bounded depth arithmetic circuits imply derandomization of polynomial identity testing for bounded depth arithmetic circuits. More formally, if there exists an explicit polynomial f(x_1,...,x_m) that cannot be computed by a depth d arithmetic circuit of small size then there exists an efficient deterministic algorithm to test whether a given depth d-8 circuit is identically zero or not (assuming the individual degrees of the tested circuit are not too high). In particular, if we are guaranteed that the tested circuit computes a multilinear polynomial then we can perform the identity test efficiently. The above results are obtained using the the arithmetic Nisan-Wigderson generator of [KabanetsImpagliazzo04] together with a new theorem on bounded depth circuits, which is the main technical contribution of our work. Joint work with Amir Shpilka and Amir Yehudayoff.