Title

It has been known for a long time that the class of self-dual codes over a finite field is asymptotically good and that it attains the Gilbert-Varshamov bound. Stichtenoth showed that over fields with quadratic cardinality self-dual codes even attain the Tsfasman-Vladut-Zink bound. In this talk I will explain how using some well-known facts about quadratic forms and a new cubic tower of curves an analogous result can be obtained for self-dual codes over cubic finite fields. This new construction also gives a simpler proof for the quadratic case. [joint work with H. Stichtenoth].