Power moments of negative order for the principal spectral function of a string

We established necessary and sufficient conditions for the existence of finite power moments of all integer negative orders for the principal spectral function of a string. The necesity of this problem is explained by its relation to the so-called strong Stieltjes moment problem. Odessa Academy of Food Technologies, Odessa. Translated from Ukrainskii Matematischeskii Zhurnal, Vol. 48, No. 9, pp. 1209–1222, September, 1996.