# FG1 Seminar talk

2015-07-15

Wilfried **Meidl***Are normal bent functions normal?*

Abstract:

Since their introduction by Rothaus in 1976, Boolean bent functions and bent
functions from *F_p^n* to *F_p*, *p* odd, attracted a lot of
attention due to connections to many areas like combinatorics, coding theory or
cryptography. Several constructions of bent functions are known, most of them
yield bent functions which exhibit certain properties: Whereas asymptotically
almost all Boolean functions are not weakly normal, most constructions of
Boolean bent functions yield weakly normal functions, i.e. Boolean functions in
dimension *n = 2m* which are affine on an *m*-dimensional subspace.

The classical constructions of *p*-ary bent functions yield so called
weakly regular bent functions, many of which are also normal (or at least almost
weakly normal). In this talk some recent results on normality and regularity of
bent functions are discussed. For instance we present constructions of
non-weakly regular bent functions, and show the normality of the famous
Coulter-Matthews bent function.