2,037 research outputs found
Anisotropic fluid spheres of embedding class one using Karmarkar condition
We obtain a new anisotropic solution for spherically symmetric spacetimes by
analysing of the Karmarkar embedding condition. For this purpose we construct a
suitable form of one of the gravitational potentials to obtain a closed form
solution. This form of the remaining gravitational potential allows us to solve
the embedding equation and integrate the field equations. The resulting new
anisotropic solution is well behaved which can be utilized to construct
realistic static fluid spheres. Also we estimated masses and radii of fluid
spheres for LMC X-4 and EXO 1785-248 by using observational data sets values.
The obtained masses and radii show that our anisotropic solution can represent
fluid spheres to a very good degree of accuracy.Comment: 16 pages, 11 figure
A family of charged compact objects with anisotropic pressure
Utilizing an ansatz developed by Maurya and co-workers we present a class of
exact solutions of the Einstein-Maxwell field equations describing a
spherically symmetric compact object. A detailed physical analysis of these
solutions in terms of stability, compactness and regularity indicate that these
solutions may be used to model strange star candidates. In particular, we model
the strange star candidate Her X-1 and show that our solution conforms to
observational data to an excellent degree of accuracy. An interesting and novel
phenomenon which arises in this model is the fact that the relative difference
between the electromagnetic force and the force due to pressure anisotropy
changes sign within the stellar interior. This may be a an additional mechanism
required for stability against cracking of the stellar object
Growth and Characterization of Fe0.95Se0.6Te0.4 Single Crystal
In this paper we present the single crystal growth of Fe0.95Se0.6Te0.4 high
TC superconducting sample by the modified Bridgman technique. The x-ray
diffraction pattern shows the single crystal nature of the sample, as only
(00l) peaks are detectable. The stoichiometric composition has been verified by
energy dispersive x-ray analysis. The superconducting transition temperature at
14 K was confirmed through DC magnetization (ZFC-FC) and resistivity
measurements. By analyzing the isothermal M-H curves, we determined the value
of H_c1 (0) ~360 Oe by extrapolating the data. The temperature coefficient of
resistivity obtained using the power law fitting was found to be 0.6. The
obtained Raman spectra at room temperature can be interpreted with the
tetragonal crystal structure and space group P4/nmm.Comment: conference pape
All spherically symmetric charged anisotropic solutions for compact star
In the present paper we develop an algorithm for all spherically symmetric
anisotropic charged fluid distribution. Considering a new source function
we find out a set of solutions which is physically well behaved and
represent compact stellar models. A detailed study specifically shows that the
models actually correspond to strange stars in terms of their mass and radius.
In this connection we investigate about several physical properties like energy
conditions, stability, mass-radius ratio, electric charge content, anisotropic
nature and surface redshift through graphical plots and mathematical
calculations. All the features from these studies are in excellent agreement
with the already available evidences in theory as well as observations.Comment: 28 pages, 15 figures, major changes in the text. arXiv admin note:
text overlap with arXiv:1408.5126 by other author
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