2,325 research outputs found
Thin Domain Walls in Lyra Geometry
This paper studies thin domain walls within the frame work of Lyra Geometry.
We have considered two models. First one is the thin domain wall with
negligible pressures perpendicular and transverse direction to the wall and
secondly, we take a particular type of thin domain wall where the pressure in
the perpendicular direction is negligible but transverse pressures are existed.
It is shown that the thin domain walls have no particle horizon and the
gravitational force due to them is attractive.Comment: 8 pages, typos are corrected, published Astrophysics and Space
Sciences 305, 337 (2006
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
Vacuumless topological defects in Lyra geometry
Few years ago, Cho and Vilenkin have proposed that topological defects can
arise in symmetry breaking models without having degenerate vacua. These types
of defects are known as vacuumless defects. In the present work, the
gravitational field of a vacuumless global string and global monopole have been
investigated in the context of Lyra geometry. We find the metric of the
vacuumless global string and global monopole in the weak field approximations.
It has been shown that the vacuumless global string can have repulsive whereas
global monopole exerts attractive gravitational effects on a test particle. It
is dissimilar to the case studied in general relativity.Comment: 14 pages, 9 figures. To appear in Astrophys.Space.Sc
A study of global monopole in Lyra geometry
A class of exact static solution around a global monopole resulting from the
breaking of a global S0(3) symmetry is obtained in the context of Lyra
geometry. Our solution is shown to possess an interesting feature like
wormholes space-time. It has been shown that the global monopole exerts no
gravitational force on surrounding non-relativistic matter.Comment: 6 pages, Published in Mod.Phys.Lett.A19:2785-2790,200
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