Let F be a field of
characteristic zero. We give the following answer to a generalization of a
problem of Büchi over F[t]: A sequence of 92 or more cubes in F[t], not
all constant, with constant third difference equal to 6, consists of cubes of
successive elements x,x + 1,…, for some x ∈ F[t]. We use this, in conjunction to
the negative answer to Hilbert’s tenth problem for F[t], to show that the
solvability of systems of degree-one equations, where some of the variables are
assumed to be cubes and (or) nonconstant, is an unsolvable problem over
F[t].
Keywords
Büchi’s Problem, Hilbert’s Tenth Problem, existential
undecidability, cubic Forms