  We study the wave function of a tensor model in the canonical formalism by
Hamiltonian Monte Carlo method for Lie group symmetric or nearby values for the
argument of the wave function, and show that there emerge Lie-group symmetric
semi-classical spacetimes. More precisely, we consider some $SO(n+1)\
(n=1,2,3)$ symmetric values for the tensor argument of the wave function, and
show that there emerge discrete $n$-dimensional spheres. A key fact is that
there exist two phases, the classical phase and the quantum phase, depending on
the values of the argument of the wave function, and emergence of classical
spaces above occurs in the former phase, while fluctuations of configurations
are too large for such emergence in the latter phase. The transition between
the two phases has similarity with the Gross-Witten-Wadia transition, or that
between the one-cut and the two-cut solutions in the matrix model. Based on the
results, we give some speculations on how spacetimes evolve in the tensor
model.
