Identification of the Order of the Fractional Derivative for the Fractional Wave Equation

A fractional wave equation with a Riemann–Liouville derivative is considered. An arbitrary self-adjoint operator discrete spectrum was taken as the elliptic part. We studied inverse problem of determining order time derivative. By setting value projection solution onto first eigenfunction at fixed point in an additional condition, uniquely restored. The abstract allows us to include many models. Several examples are discussed end article.