  The type IIB matrix model is conjectured to be a nonperturbative definition
of type IIB superstring theory. In this model, spacetime is a dynamical
quantity and compactification of extra dimensions can be realized via
spontaneous symmetry breaking(SSB). In this work, we consider a simpler,
related, six dimensional model in its Euclidean version and study it
numerically. Our calculations provide evidence that the SO(6) rotational
symmetry of the model breaks down to SO(3), which means that the theory lives
in a vacuum where 3 out of the 6 dimensions are large compared to the other 3.
Our results show the same SSB pattern predicted by the Gaussian expansion
method and that they are in quantitative agreement. The Monte Carlo simulations
are hindered by a severe complex action problem which is addressed by applying
the complex Langevin method.
