خلافت اور جمہوریت نتائج و عواقب عصر حاضر کے تناظر میں

Islām is a complete code of life. Man is the vicegerent and representative of Allāh. The role of vicegerent and caliphate can only be fulfilled in a complete manner, when the system of the Islamic Caliphate is established. It is the duty of Muslims to endeavor for establishing such a system in the world. The caliphate is the political title of Islām. It is, actually, the sovereignty of Almighty God on the earth. God creates its sovereignty by selecting the pious people from the humankind. With the help of Caliphate, unity, strength and equality can be established in the Muslim world. Democracy is the system of government, which is based on the wishes of the majority of the people of a state. However, the real democracy is the one in which wishes of people are directly or indirectly catered. An ideal democracy is the one in which all affairs of the country are run with the consultation of all the people. If the affairs of any state are run by the majority of the people, then that state will move towards its destruction. Allāh says, “O Muhammad.. ! If you obey most of the dwellers of the earth they will lead you astray from Allah’s way. ” The affairs of the Islamic state must not run by the wishes of the majority nor the minority of the people, but, on the values of truth and justice. The author of this paper presents a critical and comparative study of the Islamic Caliphate and democracy, and concludes that it is the Caliphate and not democracy, which is the true Islamic system of government.

Some Inflationary and Cosmic Issues in General Relativity

In this thesis, we investigate two interesting issues. First, we study the validity of gen- eralized second law of thermodynamics for FRW universe bounded by four horizons, i.e., Hubble, apparent, particle and event horizons in the framework of non-linear electrodynamics. We assume that the universe is composed of dark matter, magnetic ¯eld and some unknown component of dark energy with two di®erent interacting terms. It is found that energy transfer from dark energy to magnetic energy depends upon the sign of interacting terms. In this scenario, we calculate energy densities of dark matter and other dark energy °uid. It turns out that this law always holds on the Hubble and apparent horizons, but fails on the particle and event horizons for both interacting and non-interacting cases. Second, we study warm in°ation using vector ¯elds in the background of locally rotationally symmetric Bianchi I universe model. To discuss in°ation, we formulate the ¯eld equations, slow-roll and perturbation parameters (scalar and tensor power spectra, their spectral indices and tensor-scalar ratio) under slow-roll approximation. These parameters are evaluated in terms of in°aton during intermediate and logame- diate in°ationary regimes by taking variable and constant dissipation coe±cient. The graphical analysis of these parameters is shown to check compatibility of the model with WMAP7 and Planck observational data. We also deal with the dynamics of warm in°ation in which slow-roll in°ation is driven by non-Abelian gauge ¯elds in the same background metric. In this context, the solutions of in°aton and in°ationary parameters during intermediate as well as xiv xv logamediate in°ationary eras are evaluated. It is concluded that anisotropic in°ation- ary universe model with non-Abelian gauge ¯elds remain compatible with WMAP7 data. We then assume that the anisotropic universe is composed of in°aton and im- perfect °uid having radiation and bulk viscous pressure. The analysis is made by taking dissipation and bulk viscous coe±cients to be variable as well as constant. We constrain the model as well as cosmological parameters using recent Planck and WMAP7 probe. Finally, we consider an in°ationary FRW universe model in the context of gen- eralized cosmic Chaplygin gas by taking matter ¯eld as standard and tachyon scalar ¯elds. The solution of in°aton ¯elds and scalar potentials during intermediate and logamediate in°ationary regimes are found by modifying the ¯rst Friedmann equa- tion. The graphical behavior of observed physical parameter shows that the model remains incompatible with WMAP7 and Planck observational data in each case. We also study the e®ects of bulk viscous pressure on this model assuming in°aton and imperfect °uid as constituents of the universe. We evaluate in°aton ¯elds, poten- tials and entropy density for variable as well as constant dissipation and bulk viscous coe±cients in weak and strong dissipated regimes during intermediate era. The cor- responding parameters are constrained using recent Planck, WMAP7 and BICEP2 probes.