## Gil Cohen's homepage

Welcome! I am a faculty member at the Department of Computer Science at Tel Aviv University. I am working on pseudo-randomness, explicit constructions, and coding theory. Of particular interest are randomness extractors, derandomization of space-bounded computation, spectral graph theory, tree codes, locally decodable and correctable codes, and algebraic-geometric codes.

A Course on Algebraic-Geometric Codes

Next semester I will give a course on Algebraic Geometric Codes. These elegant codes beat the Gilbert-Varshamov bound (i.e., random codes) over sufficiently large (yet constant size) fields. The mathematics underlying these codes is extremely deep (and, in particular, involves the resolution of the Riemann hypothesis over function fields). If you like beautiful mathematics, in particular Galois theory and a bit of commutative algebra, join the course (either as an enrolled student or as an audit). Email me for any question. Remark: One question that I have been asked several times is whether the course can be taken in conjunction with the course Galois Theory (0366-2133). The answer is yes. We will need Galois theory mostly on the second part of the semester and we will mostly use what you'll learn by then.