R. Paternoga et R. Graham, CHERN-SIMONS STATE FOR THE NONDIAGONAL BIANCHI TYPE IX MODEL - ART. NO. 083501, Physical review. D. Particles and fields, 5808(8), 1998, pp. 3501
The Bianchi type IX mixmaster model is quantized in its nondiagonal fo
rm, imposing spatial diffeomorphism, time reparametrization, and Loren
tz invariance as constraints on physical state vectors before gauge fi
xing. The result turns out to be different from quantizing the diagona
l model obtained by gauge fixing already on the classical level. For t
he nondiagonal model a generalized nine-dimensional Fourier transforma
tion over a suitably chosen manifold connects the representations in m
etric variables and in Ashtekar variables. A space of five states in t
he metric representation is generated from the single physical Chem-Si
mons state in Ashtekar variables by choosing five different integratio
n manifolds, which cannot be deformed into each other. For the case of
a positive cosmological constant Lambda we extend our previous study
of these five states for the diagonal Bianchi type IX model to the non
diagonal case. It is shown that additional discrete (permutation) symm
etries of physical states arise in the quantization of the nondiagonal
model, which are satisfied by two of the five states connected to the
Chern-Simons state. These have the characteristics of a wormhole grou
nd state and a Hartle-Hawking ''no-boundary'' state, respectively. We
also exhibit a special gauge fixing of the time reparametrization inva
riance of the quantized system and define an associated manifestly pos
itive scalar product. Then the wormhole ground state is left as the on
ly normalizable physical state connected to the Chern-Simons state. [S
0556-2821(98)04316-1].