119341992
Phase transition and properties of a compact star
We investigate the phase transition to a deconfined phase and the consequences in the formation of neutron stars. We use the recently proposed effective-field-theory-motivated relativistic mean-field theory for the hadrons and the MIT bag model and color-flavor locked (CFL) phase for the quark matter to get the appropriate equation of state. The properties of the stars are then calculated. The differences between unpaired and CFL quark matter are discussed.
121013898
Relativistic mean field study of clustering in light nuclei
The clustering phenomenon in light, stable and exotic nuclei is studied within the relativistic mean field (RMF) approach. Numerical calculations are done by using the axially deformed harmonic oscillator basis. The calculated nucleon density distributions and deformation parameters are analyzed to look for the cluster configurations. The calculations explain many of the well-established cluster structures in both the ground and intrinsic excited states. Comparisons of our results with other model calculations and the available experimental information suggest that the RMF theory is well suited for studying clustering in light nuclei. A few discrepancies and their possible sources are also discussed.
119377258
Versatility of field theory motivated nuclear effective Lagrangian approach
Abstract We analyze the results for infinite nuclear and neutron matter using the standard relativistic mean field model and its recent effective field theory motivated generalization. For the first time, we show quantitatively that the inclusion in the effective theory of vector meson self-interactions and scalar–vector cross-interactions explains naturally the recent experimental observations of the softness of the nuclear equation of state, without losing the advantages of the standard relativistic model for finite nuclei.
119189441
Basic Mechanics of Planet-Satellite Interaction with special reference to Earth-Moon System
In1879 George Howard Darwin theoretically analyzed the outward spiraling orbit of Moon and the subsequent lengthening of the Mean Solar Day. The author redid the same analysis based on the fact that Moon was receding at the rate of 3.8 cm per annum. Basic Mechanics of Earth-Moon is worked out and various system parameters are optimized to fit the given boundary condition obtained by Apollo Mission and other modern means of observations. Based on this theoretical formulation the theoretical graph of the lengthening of the Mean Solar Day with respect to time is drawn and is compared with the observational graph of the same based on pale ontological data, paleo tidal data and iron-banded formation. The observational data on Mean Solar Day is found to follow the theoretical smooth curve in post-Cambrian Era but is found to deviate in the remote past. This deviation is corrected by taking the evolving form of Moment of Inertia of Earth. The deviation of the observed data prompts the Author to suggest that the lengthening of the Mean Solar Day curve could possibly be used as an analytical seismograph for the impending earthquakes and sudden volcanic eruptions. The Basic Mechanics of E-M system is generalized to lay the foundation of simulation software for any Planet-Satellite pair in our Solar System.
118316994
Irregularly Shaped Satellites-Phobos & Deimos- moons of Mars, and their evolutionary history
Phobos, a moon of Mars, is below the Clarke synchronous orbit and due to tidal interaction is losing altitude. With this altitude loss it is doomed to the fate of total destruction by direct collision with Mars. On the other hand Deimos, the second moon of Mars is in extra-synchronous orbit and almost stay put in the present orbit. The reported altitude loss of Phobos is two meter per century by wikipedia and sixty ft per century according to ozgate url . The reported time in which the destruction will take place is fiftyMy and fortyMy respectively. The authors had proposed a planetary-satellite dynamics based on detailed study of Earth-Moon. Based on this planetary satellite dynamics, two meter/century approach velocity leads to the age of Phobos to be twenty three Gyrs which is physically untenable since our Solar System age is four and a half Gyrs. Hence the present altitude loss is assumed to be twenty meter per century. This leads to the age of Phobos to be two decimal three Gyrs and age of Deimos to be two decimal two six Gyrs which is an acceptable result and from this analysis it is predicted that the travel time from the present orbital radius of nine thousand three hundred and eighty km to the Martian surface at three thousand, three hundred and ninety seven km is ten decimal and four Myrs. Hence doomsday of Phobos is at ten decimal and fourMyrs from now. Mars Express studies have confirmed that Phobos is indeed trapped in a death spiral.