We present a characteristic algorithm for computing the perturbation of a Schwarzschild spacetime by means of solving the Teukolsky equation. We implement the algorithm as a characteristic evolution code and apply it to compute the advanced solution to a black hole collision in the close approximation. The code successfully tracks the initial burst and quasinormal decay of a black hole perturba...

Objective(s) To determine the potential toxic effects of manual soldering flux cored solder wire on lung of the rat as an experimental model. Materials and Methods A total number of 48 adult male rats were divided into experimental (n= 30) and control (n= 18) groups. Based on exposure time to solder fume, each group was further subdivided into 2, 4 and 6 week subgroups. Rats of experimental ...

We develop an analytical ringdown waveform model, including both the fundamental and overtone quasinormal modes, for charged black holes show that it is precise enough to analyze current gravitational wave data. Applying this model GW150914, charge mass ratio of remnant hole (${\ensuremath{\lambda}}_{f}$) has been constrained with sole data first time 90% upper limit ${\ensuremath{\lambda}}_{f}...

The nonextreme Dp-brane solutions in type II supergravity (in the near-horizon limit) are expected to be dual to (p+ 1)-dimensional noncompact supersymmetric Yang-Mills theories at finite temperature. We study the translationally invariant perturbations along the branes in those backgrounds and calculate quasinormal frequencies numerically. These frequencies should determine the thermalization ...

We establish an exact connection between the Choptuik scaling parameter for the three-dimensional BTZ black hole, and the imaginary part of the quasinormal frequencies for scalar perturbations. Via the AdS/CFT correspondence, this leads to an interpretation of Choptuik scaling in terms of the timescale for return to equilibrium of the dual conformal field theory.

Let S∞ denote the symmetric group on the natural numbers N. Then S∞ is a Polish group with the topology inherited from NN with the product topology and the discrete topology on N. Let d denote the least cardinality of a dominating family for NN and let c denote the continuum. Using theorems of Galvin, and Bergman and Shelah we prove that if G is any subgroup of S∞ that is closed in the above to...

Objective(s): The present study aimed to assess the in-vitro efficacy of nanoparticulate calcium sodium phosphosilicate mouthwash in the obstruction of dentinal tubules.Materials and Methods: This in-vitro, study was conducted on 120 sections obtained from extracted human premolars, which were etched with citric acid for two minutes and rinsed with distilled water. Afterwards, the section...

We provide a complete classification of asymptotic quasinormal frequencies for static, spherically symmetric black hole spacetimes in d dimensions. This includes all possible types of gravitational perturbations (tensor, vector and scalar type) as described by the Ishibashi–Kodama master equations. The frequencies for Schwarzschild are dimension independent, while for Reissner–Nordstrøm are dim...

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...

in this paper, we introduce some properties of an intuitionistic normal fuzzy m-subgroup of m- group with m-homomorphism and isomorphism. we study he image, the pre-image and the inverse mapping of the intuitionistic normal fuzzy m-‎subgroups.‎