The Influence of the Shear on the Gravitational Waves in the Early
  Anisotropic Universe
  We study the singularity of the congruences for both timelike and null
geodesic curves using the expansion of the early anisotropic Bianchi type I
Universe. In this paper, we concentrate on the influence of the shear of the
timelike and null geodesic congruences in the early Universe. Under some
natural conditions, we derive the Raychaudhuri type equation for the expansion
and the shear-related equations. Recently, scientists working on the LIGO
(Laser Interferometer Gravitational-Wave Observatory) have shown many
possibilities to observing the anisotropy of the primordial gravitational wave
background radiation. We deduce the evolution equation for the shear that may
be responsible for those observational results.
