Delineating of groundwater potential zones based on remote sensing,GIS and analytical hierarchical process: a case of Waddai,eastern Chad

GeoJournal - The delineation of favourable areas of water potentials and their management must be based on rigorous scientific studies. Thus, geographic information system (GIS) and remote sensing...     

Quasinormal modes and Hawking radiation of a Reissner-Nordström black hole surrounded by quintessence

We investigate quasinormal modes (QNMs) and Hawking radiation of a Reissner-Nordström black hole surrounded by quintessence. The Wentzel-Kramers-Brillouin (WKB) method is used to evaluate the QNMs and the rate of radiation. The results show that due to the interaction of the quintessence with the background metric, the QNMs of the black hole damp more slowly when increasing the density of quintessence and the black hole radiates at slower rate.     

Quasinormal modes of scalar perturbation around a quantum-corrected Schwarzschild black hole

In this paper, we evaluate quasinormal modes (QNMs) of scalar perturbations around a quantum-corrected Schwarzschild black hole by using the third order Wentzel-Kramers-Brillouin (WKB) approximation method. The results show that due to the quantum fluctuations in the background of the Schwarzschild black hole, the QNMs of the black hole damp more slowly when increasing the quantum correction factor (a), and oscillate more slowly.