### Speaker

Dr
Bijan Saha
(Laboratory of Information Technologies, Joint Institute for Nuclear Research)

### Description

Within the scope of non-diagonal Bianchi cosmological models we have
studied the role of spinor field in the evolution of the Universe.
Unlike in diagonal Bianchi models such as I, III, V, VI0
and VI where spinor field distribution along the main axis is
isotropic and becomes zero for linear spinor field, in case
(non-diagonal) Bianchi models such as II, VIII and IX, spinor
field distribution along the main axis is anisotropic and does not
vanish in absence of spinor field nonlinearity. The equation for
volume scale V in case of diagonal Bianchi models can be resolved
exactly and the corresponding solution can be presented as
quadrature. In case of non-diagonal Bianchi models the corresponding
equation contains a term with the firs derivative of V explicitly and does not allow
exact solution in quadrature.
In absence of non-diagonal components of energy-momentum tensor non-diagonal Bianchi spacetime becomes locally rotationally symmetric.
Inclusion of spinor field does not change the situation as well.
It was found that depending on the sign of coupling constant the
model allows either an open Universe that rapidly grows up or a
close Universe that ends in Big Crunch singularity.

### Primary author

Dr
Bijan Saha
(Laboratory of Information Technologies, Joint Institute for Nuclear Research)