We study the asymptotic quasinormal modes for the scalar perturbation of the noncommutative geometry inspired Schwarzschild black hole in (3+1) dimensions. We have considered M ≥ M0, which effectively correspond to a single horizon Schwarzschild black hole with correction due to noncommutativity. We have shown that for this situation the real part of the asymptotic quasinormal frequency is prop...

There is a well-known, intuitive geometric correspondence between high-frequency quasinormal modes of Schwarzschild black holes and null geodesics that reside on the light ring (often called spherical photon orbits): the real part of the mode’s frequency relates to the geodesic’s orbital frequency, and the imaginary part of the frequency corresponds to the Lyapunov exponent of the orbit. For sl...

The present study aimed to compare post-aging microtensile values of fissure sealant(FS) containing amorphous calcium phosphate(ACP) with or without bonding after various enamel-etching methods. The buccal enamel surfaces of teeth were prepared and divided into five main groups according to enamel etching (Group 1; acid-etching, Group 2; air-abrasion, Group 3; 2W, Group 4; 3W, and Group 5; 4W o...

We show that strongly coupled field theories with holographic gravity duals at finite charge density and low temperatures can undergo de Haas van Alphen quantum oscillations as a function of an external magnetic field. Exhibiting this effect requires computation of the one loop contribution of charged bulk fermions to the free energy. The one loop calculation is performed using a formula expres...

We present the quasinormal frequencies of the massive scalar field in the background of a Schwarzchild black hole surrounded by quintessence with the third-order WKB method. The mass of the scalar field u plays an important role in studying the quasinormal frequencies, the real part of the frequencies increases linearly as mass u increases, while the imaginary part in absolute value decreases l...

We investigate the quasinormal modes for gravitational perturbations of rotating black holes in four dimensional Anti-de Sitter (AdS) spacetime. The study of the quasinormal frequencies related to these modes is relevant to the AdS/CFT correspondence. Although results have been obtained for Schwarzschild and Reissner-Nordstrom AdS black holes, quasinormal frequencies of Kerr-AdS black holes are...

Recent observational results suggest that the universe in large scale is described by an Einstein equation with an (at least effective) cosmological constant. In this context, the dynamics of fields in spacetimes which are not asymptotically flat has taken on new importance. Quasinormal modes are a fundamental part of this dynamics. In general, perturbations in the spacetime exterior of a black...

More than three decades ago, Detweiler provided an analytical formula for the gravitational resonant frequencies of rapidly-rotating Kerr black holes. In the present work we shall discuss an important discrepancy between the famous analytical prediction of Detweiler and the recent numerical results of Zimmerman et al. In addition, we shall refute the claim that recently appeared in the physics ...

The study of quasinormal modes in a black hole background spacetime has a long history [1]-[19]. It is shown that their frequencies and damping times are entirely fixed by the black hole parameters and independent of the initial perturbations. Therefore, it is certain that quasinormal modes carry the characteristic information about a black hole and it can provide a new and direct way for astro...

We sketch the results of calculations of the quasinormal frequencies of the electrically charged dilaton black hole. At the earlier phase of evaporation (Q is less than 0.7−0.8M), the dilaton black hole " rings " with the complex frequencies which differ negligibly from those of the Reissner-Nordström black hole. The spectrum of the frequencies weakly depends upon the dilaton coupling. When per...