Search of wormholes in different dimensional non-commutative inspired space-time with lorentzian distribution

In this paper we are searching whether the wormhole solutions exists in different dimensional non- commutative inspired spacetimes. It is well known that the noncommutativity of the space is an outcome of string theory and it replaced the usual point like object by a smeared object. Here we have chosen Lorentzian distribution as the density function in the noncommutative inspired space- time. We have observed that the wormhole solutions exist only in four and five dimension, however, higher than fine dimension no wormhole exists. For five dimensional spacetime, we get a wormhole for a restricted region. In usual four dimensional spacetime, we get a stable wormhole which is asymptotically flat.Comment: 13 pages,23 figures, Accepted in European Physical Journal

The Dark Energy Star and Stability analysis

We have proposed a new model of dark energy star consisting of five zones namely, solid core of constant energy density, the thin shell between core and interior, an inhomogeneous interior region with anisotropic pressures, thin shell and the exterior vacuum region. We have discussed various physical properties. The model satisfies all the physical requirements. The stability condition under small linear perturbation has also been discussed.Comment: 11 pages,16 figures, Accepted in European Physical Journal

Višedimenzijski globalni monopol u Lyrinoj geometriji

We present an approximate solution around a global monopole resulting from a breaking of a global SO(3) symmetry in a five-dimensional space-time based on Lyra’s geometry in normal gauge, i.e., displacement vector φi = (0, 0, 0, 0, β0), where β0 is a constant. Acceleration due to the monopole has been evaluated by studying the geodesic equation. A comparison is made with the classical results.Dajemo približno rješenje oko globalnog monopola koje slijedi kršenje globalne SO(3) simetrije u peto-dimenzijskom prostoru-vremenu, zasnovano na Lyrinoj geometriji u normalnoj baždarnosti, tj., pomačni je vektor φi = (0, 0, 0, 0, β0), uz β0 = const. Ubrzanje zbog monopola odred–uje se promatranjem geodetske jednadžbe. Načinili smo usporedbu s klasičnim rezultatima

A class of interior solutions corresponding to a (2+1)(2+1) dimensional asymptotically anti-de Sitter spacetime

Lower dimensional gravity has the potential of providing non-trivial and valuable insight into some of the conceptual issues arising in four dimensional relativistic gravitational analysis. The asymptotically anti-de Sitter (2+1) dimensional spacetime described by Ba$\tilde{n}$ados, Teitelboim and Zanelli (BTZ) which admits a black hole solution, has become a source of fascination for theoretical physicists in recent years. By suitably choosing the form of the mass function $m(r)$, we derive a new class of solutions for the interior of an isotropic star corresponding to the exterior (2+1) asymptotically anti-de Sitter BTZ spacetime. The solution obtained satisfies all the regularity conditions and its simple analytical form helps us to study the physical parameters of the configuration in a simple manner.Comment: 5 pages, 5 figures. Accepted for publication in Phys. Lett. B, some typos are correcte

Višedimenzijski globalni monopol u Lyrinoj geometriji

We present an approximate solution around a global monopole resulting from a breaking of a global SO(3) symmetry in a five-dimensional space-time based on Lyra’s geometry in normal gauge, i.e., displacement vector φi = (0, 0, 0, 0, β0), where β0 is a constant. Acceleration due to the monopole has been evaluated by studying the geodesic equation. A comparison is made with the classical results.Dajemo približno rješenje oko globalnog monopola koje slijedi kršenje globalne SO(3) simetrije u peto-dimenzijskom prostoru-vremenu, zasnovano na Lyrinoj geometriji u normalnoj baždarnosti, tj., pomačni je vektor φi = (0, 0, 0, 0, β0), uz β0 = const. Ubrzanje zbog monopola odred–uje se promatranjem geodetske jednadžbe. Načinili smo usporedbu s klasičnim rezultatima