  In arXiv:1601.02203, a simple model has been proposed in order to solve one
of the problems related with the cosmological constant. The model is given by a
topological field theory and the model has an infinite numbers of the BRS
symmetries. The BRS symmetries are, however, spontaneously broken in general.
In this paper, we investigate the BRS symmetry in more details and show that
there is one and only one BRS symmetry which is not broken and the unitarity
can be guaranteed. In the model, the quantum problem of the vacuum energy,
which may be identified with the cosmological constant, reduces to the
classical problem of the initial condition. In this paper, we investigate the
cosmology given by the model and specify the region of the initial conditions
which could be consistent with the evolution of the universe. We also show that
there is a stable solution describing the de Sitter space-time, which may
explain the accelerating expansion in the current universe.
