High-entropy dual functions over finite fields and locally decodable codes

Jop Briët, Farrokh Labib
2021 Forum of Mathematics, Sigma  
We show that for infinitely many primes p there exist dual functions of order k over ${\mathbb{F}}_p^n$ that cannot be approximated in $L_\infty $ -distance by polynomial phase functions of degree $k-1$ . This answers in the negative a natural finite-field analogue of a problem of Frantzikinakis on $L_\infty $ -approximations of dual functions over ${\mathbb{N}}$ (a.k.a. multiple correlation sequences) by nilsequences.
doi:10.1017/fms.2021.1 fatcat:itxoj2gexbfzrn6lid67ho2vve