Document Details

Document Type : Thesis 
Document Title :
Analytical and Computanal developments of N_Dimensional Radialy symmetric polytropes and Isothermal Configurations.
التكوينات التحليلية والحسابية في الفراغ النوني للنماذج البولوتروبية والحرارية ذات التماثل القطرية
 
Subject : Faculty of Sciences 
Document Language : Arabic 
Abstract : Polytropic models are vital for two classes of theoretical astrophysics: stellar structure and cosmic dynamics. In fact, the polytrope representation of stars models, is a method that today still lends valuable technique and insights to the internal structure of stars. It is also proven to be most versatile in examination of a variety of situations, including the analysis of isothermal cores, convective stellar interiors and fully degenerate stellar configurations. In cosmic dynamics, the Lane-Emden equation of the polytropic equilibrium configurations is considered as generating function of potential models for flattened galactic systems, upon such potentials the forces and the star orbits in these systems could be determined. Moreover, the effects of a positive cosmological constant on astrophysical and cosmological configurations described by polytrobic equation of state. In brief, great efforts has been devoted up to now, and is being devoted at present to express some characteristic physical parameters related to ploytrobic models. In the present thesis, literal analytical expressions in power series forms are established for the physical characteristics of N-dimensional radially symmetric polytropes and isothermal configurations. The importance of these expressions is due to some factors of these are:(i) their analytical forms, offer in general much deeper insight into the nature of the physical characteristics to which they refer. (ii)These expressions are general in the sense that they could be used for any geometric index N and for any polytropic index n, so they can suit many of the applications polytropes and isothermal configurations. (iii)The coefficients of each of these expressions have been found directly without the use of recurrence formulae. On the other hand we used for the computational developments of these expressions the continued fraction theory. The continued fraction not given the prominence they deserve in the university curricula despite the fact that they are generally, far more efficient tools for evaluating the classical functions than the more familiar infinite power series. Their convergence is typically faster and more extensive than the series and, ironically, they were in use centuries before the invention of the power series. 
Supervisor : dr.Sharaf, M.A 
Thesis Type : Master Thesis 
Publishing Year : 1431 AH
2010 AD 
Co-Supervisor : dr.Magdy Ibrahim Imam EL-Saftawy 
Added Date : Sunday, May 30, 2010 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
فيروز محمد الجدعانيAL-JEADDANE, FAIROZ MOHAMMADResearcherMaster 

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