Let
PK(n,d) be the set of polynomials in
n variables of degree at most
d over the field
K of characteristic zero. We show that there is a number
cn,d such that if
fPK(n,d) then the algebraic de Rham cohomology group
HdRi(KnVar(f)) has rank at most
cn,d. We also show the existence of a bound
cn,d,l for the ranks of de Rham cohomology groups of complements of varieties in
n-space defined by the vanishing of
l polynomials in
PK(n,d). In fact, if
βi:PK(n,d)l→N is the
ith Betti number of the complement of the corresponding variety, we establish the existence of a
Q-algebraic stratification on
PK(n,d)l such that
βi is constant on each stratum.