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present study, we
have obtained a new analytical solution of combined Einstein-Maxwell field equations describing the interior field of a ball
having static spherically symmetric isotropic charged fluid within it.
The charge and electric field intensity are zero at the center and
monotonically increasing towards the boundary of the fluid ball. Besides these, adiabatic index is also
increasing towards the boundary and becomes infinite on it. All other physical
quantities such as pressure, density, adiabatic speed of sound, charge density,
adiabatic index are monotonically decreasing towards the surface. Causality
condition is obeyed at the center of ball. In the limiting case of vanishingly small charge, the solution
degenerates into Schwarzchild uniform density solution for electrically
neutral fluid. The solution joins smoothly to the Reissner-Nordstrom solution over the boundary. We have
constructed a neutron star model by assuming
the surface density . The mass of the neutron star comes with radius
A scheme of teleporting a superposition of coherent states |α> and |-α> using a 4-partite state, a beam splitter and two phase shifters was proposed by N. Ba An (Phys. Rev. A, 68, 022321, 2003). The author concluded that the probability for successful teleportation is only 1/4 in the limit |α|→∞ and 1/2 in the limit |α|→∞. In this paper it is shown that the author’s scheme can be altered slightly so as to obtain an almost perfect teleportation for an appreciable value of |α|2. We find the minimum assured fidelity i.e., the minimum fidelity for an arbitrarily chosen information state, which we write MAF in this paper, for different cases. We also discuss the effect of decoherence on teleportation fidelity. We find that if no photons are counted in both final outputs, MAF, is still nonzero except when there is no decoherence and the initial state (the state to be teleported) is even coherent state. For non-zero photon counts, MAF decreases with increase in |α|2 for low noise. For high noise, however, it increases, attains a maximum value and then decreases with |α|2. The average fidelity depends appreciably on the initial state for low values of |α|2 only.