  Recent studies of electrical transport, both theoretical and experimental,
near the bandwidth-tuned Mott metal-insulator transition have uncovered
apparent quantum critical scaling of the electrical resistivity at elevated
temperatures, despite the fact that the actual low-temperature phase transition
is of first order. This raises the question whether there is a hidden Mott
quantum critical point. Here we argue that the dynamical mean-field theory of
the Hubbard model admits, in the low-temperature limit, asymptotically
scale-invariant (i.e. power-law) solutions, corresponding to the metastable
insulator at the boundary of metal-insulator coexistence region, which can be
linked to the physics of the pseudogap Anderson model. While our
state-of-the-art numerical renormalization group calculations reveal that this
asymptotic regime is restricted to very small energies and temperatures and
hence difficult to access numerically, we uncover the existence of a wide
crossover regime where the single-particle spectrum displays a \emph{different}
power law. We show that it is this power-law regime, corresponding to
approximate local quantum criticality, which is continuously connected to and
responsible for the apparent quantum critical scaling above the classical
critical end point. We connect our findings to experiments on tunable Mott
materials.
