The Fourier-Bessel transform and fractional powers of differential operators. (Q1432306)

The author uses the Fourier-Bessel transformation to study fractional powers of the differential operator \[ \frac {\partial^2} {\partial x_1^2} +\cdots+ \frac {\partial^2} {\partial x_p^2}- \frac {\partial^2} {\partial x_{p+1}^2} -\cdots- \frac {\partial^2} {\partial x_{p+q}^2}- \frac {\tau} {x_{p+q}} \frac {\partial} {\partial x_{p+q}}. \]