Traditionally Bessel functions are considered in the spaces L(2)(0, 1;
x) and L(2)(0, infinity; x), where the weight function x is the coeff
icient of lambda in the formally self-adjoint differential equation -(
xy')' + (n(2)/x)y = lambda xy, satisfied by the Bessel functions J(n)(
root lambda x), J(-n)(root lambda x) and/or Y-n(root lambda x). We exa
mine instead the same equation and its solutions in a Sobolev spaces H
-1, generated in part by the left side of the differential equation. T
he Bessel operators remain self-adjoint and their spectral resolutions
remain the same in the new settings.