15 research outputs found
Axially Symmetric Cosmological Mesonic Stiff Fluid Models in Lyra's Geometry
In this paper, we obtained a new class of axially symmetric cosmological
mesonic stiff fluid models in the context of Lyra's geometry. Expressions for
the energy, pressure and the massless scalar field are derived by considering
the time dependent displacement field. We found that the mesonic scalar field
depends on only coordinate. Some physical properties of the obtained models
are discussed.Comment: 13 pages, no figures, typos correcte
Gravitational field of domain wall in Lyra geometry
In this paper, we study the domain wall with time dependent displacement
vectors based on Lyra geometry in normal gauge i.e. displacement vector . The field theoretic energy momentum tensor is
considered with zero pressure perpendicular to the wall. We find an exact
solutions of Einstein equation for a scalar field with a potential
describing the gravitational field of a plane symmetric domain wall.
We have seen that the hyper surfaces parallel to the wall ()
are three dimensional de-sitter spaces. It is also shown that the gravitational
field experienced by test particle is attractive.Comment: 11 pages, 6 figures; Submitted in Astrophysics and Space Science
after minor revisio
Lyra's Cosmology of Massive String in Anisotropic Bianchi-II Space-time
The paper deals with a spatially homogeneous and totally anisotropic Bianchi
II cosmological models representing massive strings in normal gauge for Lyra's
manifold. The modified Einstein's field equations have been solved by applying
variation law for Hubble's parameter. This law generates two type of solutions
for average scale factor, one is of power law type and other is of exponential
law type. The power law describes the dynamics of Universe from big bang to
present epoch while exponential law seems reasonable to project dynamics of
future Universe. It has been found that the displacement actor is a
decreasing function of time and it approaches to small positive value at late
time, which is collaborated with Halford (1970) as well as recent observations
of SN Ia. The study reveals that massive strings dominate in early Universe and
eventually disappear from Universe for sufficiently large time, which is in
agreement with the current astronomical observations.Comment: 12 pages, 5 figure