علم الروایہ و الدرايۃ٬ مفہوم اور تاریخی پس منظر

Hadith and Science of Hadith are the terms used by specialists of Hadith known as Mohaditeen. A hadith is a recorded statement, action or approval of the Prophet Muhammad (S.A.W). It is considered as the second primary source of Islamic law after Quran. It is also a part of revelation. Prophet Muhammad (S.A.W) described it through his words. The science of hadith examplifies the principles with which a specialist in the field of Hadith evaluates the authenticity and accuracy of narrations. In the past there were two specific and developmental stages for the Books of Hadith terminology. In its 1st stage, the Scholars focused on the compilation of the statements of earlier scholars, quoting the expressions they had used without evaluating those terms or suggesting terms applicable to those expressions. This methodology was adopted by the earlier scholars such as Yaḥyā ibn Ma`īn, `Alī ibn al-Madīnī, Muslim ibn al-Ḥajjāj, and Al – Tirmidi. In the second period the Authors cited the quoted statements of the earlier works and began the collection and codification of relevant terms. In this period, the specific Principles were established. Examples of books authored in this manner are: Ma`rifah `Ulūm al-Ḥadīth by al-Ḥākim, Al-Kifāyah by al-Khaṭīb alBaghdādī and the Introduction of Ibn al-Ṣalāḥ. In this article the two major types of science of Hadith have been mentioned, Rewayat-ul-Hadith and Derayat-ulHadith. Its definition and historical background has been described.

Spatial Damping of Electromagnetic Waves in Plasma

In this dissertation, the spatial damping of electromagnetic waves is studied by employing the kinetic theory. In particular, spatial damping of right handed and left handed (R-L) circularly polarized waves, ordinary wave and extraordinary wave is discussed in collisionless plasmas by using the Maxwellian velocity distribution of electrons. In this analysis, we have taken the wave vector to be complex but the wave frequency as real, which contrasts to the customary approach in which the wave frequency is taken complex while the wave vector is real. A comparison is made between numerical and analytical results. For R-L waves, it is investigated that in the hot plasma spatial damping properties can be significantly different from the cold plasma. The possible reason is wave-particle interaction (cyclotron resonance) and higher order thermal effects. It is also shown that the response of plasma to the interacting electromagnetic wave shows the variety of changes in different frequency domains. For perpendicular propagating ordinary and extraordinary modes, the spatial attenuation is investigated by employing the numerical and analytical methods to unveil the complicated structure. The banded attenuation between the harmonics is theoretically investigated, which may have applications both for laboratory and space plasmas. Specifically we have examined how the imaginary wave vector is incorporated with the Poynting flux theorem for circularly polarized wave (CPW) in bi- kappa distributed plasma. We also noticed how the energy flux is affected when the parallel and perpendicular temperatures are different with respect to the direction of ambient magnetic field. It is found that the CPW transports its energy rapidly when the perpendicular temperature is larger than the parallel temperature to the background magnetic field. We also investigated how the wave delivers its energy rapidly over long distance for low values of kappa spectral index (κ). Thus the two parameters, temperature anisotropy and kappa index, control the transport of wave energy.