CHARACTERIZATION OF POLYNOMIALS
Abstract
In 1954, it was proved that if f is infinitely differentiable in the interval I and some derivatives (of order depending on x) vanish at each x, then f is a polynomial. Later, it was generalized for the multivariable case. A further extension for distributions is possible. If Ω ⊆ Rn is a non-empty connected open set, and for every
, there exists m(φ) ∈ N such that (Dαu)(φ) = 0 for all multi-indices α satisfying ‖α‖ = m(φ), then u is a polynomial (in distributional sense).