Using both the second order correction of perturbation theory and the exact
computation due to Dalgarno-Lewis, we compute the second order noncommutative
Stark effect,i.e., shifts in the ground state energy of the hydrogen atom in
the noncommutative space in an external electric field. As a side result we
also obtain a sum rule for the mean oscillator strength. The energy shift at
the lowest order is quadratic in both the electric field and the noncommutative
parameter θ. As a result of noncommutative effects the total
polarizability of the ground state is no longer diagonal.Comment: 7 pages, no figure