R. Froese, UPPER-BOUNDS FOR THE RESONANCE COUNTING FUNCTION OF SCHRODINGER-OPERATORS IN ODD DIMENSIONS, Canadian journal of mathematics, 50(3), 1998, pp. 538-546
The purpose of this note is to provide a simple proof of the sharp pol
ynomial upper bound for the resonance counting function of a Schroding
er operator in odd dimensions. At the same time we generalize the resu
lt to the class of super-exponentially decreasing potentials.