scholarly journals Dispersion modes of hot plasma for a Schwarzschild – de Sitter horizon in a Veselago medium

2011 ◽  
Vol 89 (10) ◽  
pp. 991-1002 ◽  
Author(s):  
M. Sharif ◽  
Ifra Noureen
Keyword(s):  
Refractive Index ◽  
Graphical Representation ◽  
Refractive Index Change ◽  
Magnetized Plasma ◽  
Linear Perturbation ◽  
De Sitter ◽  
Hot Plasma ◽  
Veselago Medium ◽  
General Relativistic ◽  
Grmhd Equations

Herein, we analyze the dispersion modes of hot plasma around the Schwarzschild – de Sitter event horizon in the presence of a Veselago medium (left-handed). For this purpose, we apply Arnowitt, Deser, and Misner 3+1 formalism to develop general relativistic magnetohydrodynamics (GRMHD) equations for the Schwarzschild – de Sitter space–time. Implementation of linear perturbation yields perturbed GRMHD equations that are used for the Fourier analysis of rotating (nonmagnetized and magnetized) plasma. Wave analysis is described by the graphical representation of the wave vector, refractive index, change in refractive index, and phase and group velocities. The outcome of this work supports the validity of a Veselago medium.

scholarly journals Hot plasma modes across Reissner–Nördstrom–de Sitter horizon in a Veselago medium

2015 ◽  
Vol 93 (5) ◽  
pp. 565-573
Author(s):  
Ifra Noureen ◽  
Hafiza Rizwana Kausar
Keyword(s):  
Fourier Analysis ◽  
Wave Dispersion ◽  
Plasma Waves ◽  
Perturbation Scheme ◽  
De Sitter ◽  
Hot Plasma ◽  
Veselago Medium ◽  
General Relativistic ◽  
Grmhd Equations ◽  
Wave Properties

We investigate wave attributes of hot plasma around a Reissner–Nördstrom–de Sitter (RN-dS) metric in a Veselago medium. A perturbation scheme is implemented on general relativistic magnetohydrodynamical (GRMHD) equations that are further used for Fourier analysis. The linearly perturbed Fourier-analyzed GRMHD equations depict the dispersion of hot plasma waves. It is found that inclusion of charge in de Sitter space greatly affects the wave dispersion. A comparison of wave properties is presented, and results reassert the presence of the Veselago medium.

DISPERSION RELATIONS FOR COLD PLASMA AROUND THE HORIZON OF SCHWARZSCHILD–DE SITTER BLACK HOLE

2010 ◽  
Vol 19 (02) ◽  
pp. 113-135
Author(s):  
M. KHAYRUL HASAN
Keyword(s):  
Black Hole ◽  
Cold Plasma ◽  
Wave Number ◽  
Linear Perturbation ◽  
De Sitter ◽  
Rindler Coordinates ◽  
General Relativistic ◽  
Phase And Group Velocities ◽  
The Waves ◽  
Complex Dispersion

In this paper, we investigate the wave properties of cold plasma in the vicinity of Schawarzchild–de Sitter black hole horizon using 3 + 1 formalism. The general relativistic magnetohydrodynamical equations are formulated for this space–time with the use of Rindler coordinates. We consider both the rotating and nonrotating surroundings with magnetized and nonmagnetized plasmas. Linear perturbation and Fourier analysis techniques are applied by introducing simple harmonic waves. We derive complex dispersion relation from the determinant of Fourier analyzed equations for each case which provides real and complex values of the wave number. From the wave number we determine the phase and group velocities, the refractive index etc., which are used to discuss the characteristics of the waves around the event horizon.

scholarly journals Critical angle reflection imaging for quantification of molecular interactions on glass surface

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guangzhong Ma ◽  
Runli Liang ◽  
Zijian Wan ◽  
Shaopeng Wang
Keyword(s):  
Refractive Index ◽  
Small Molecule ◽  
Molecular Interactions ◽  
Glass Surface ◽  
Critical Angle ◽  
Dynamic Range ◽  
Refractive Index Change ◽  
Label Free ◽  
Index Change ◽  
Sensing Range

AbstractQuantification of molecular interactions on a surface is typically achieved via label-free techniques such as surface plasmon resonance (SPR). The sensitivity of SPR originates from the characteristic that the SPR angle is sensitive to the surface refractive index change. Analogously, in another interfacial optical phenomenon, total internal reflection, the critical angle is also refractive index dependent. Therefore, surface refractive index change can also be quantified by measuring the reflectivity near the critical angle. Based on this concept, we develop a method called critical angle reflection (CAR) imaging to quantify molecular interactions on glass surface. CAR imaging can be performed on SPR imaging setups. Through a side-by-side comparison, we show that CAR is capable of most molecular interaction measurements that SPR performs, including proteins, nucleic acids and cell-based detections. In addition, we show that CAR can detect small molecule bindings and intracellular signals beyond SPR sensing range. CAR exhibits several distinct characteristics, including tunable sensitivity and dynamic range, deeper vertical sensing range, fluorescence compatibility, broader wavelength and polarization of light selection, and glass surface chemistry. We anticipate CAR can expand SPR′s capability in small molecule detection, whole cell-based detection, simultaneous fluorescence imaging, and broader conjugation chemistry.

scholarly journals Influence of the geometric configuration of accretion flow on the black hole spin dependence of relativistic acoustic geometry

2018 ◽  
Vol 27 (03) ◽  
pp. 1850023 ◽  
Author(s):  
Pratik Tarafdar ◽  
Tapas K. Das
Keyword(s):  
Black Hole ◽  
Kerr Black Hole ◽  
Geometric Configuration ◽  
Surface Gravity ◽  
Linear Perturbation ◽  
Flow Profile ◽  
White Hole ◽  
Accretion Flow ◽  
Black Hole Spin ◽  
General Relativistic

Linear perturbation of general relativistic accretion of low angular momentum hydrodynamic fluid onto a Kerr black hole leads to the formation of curved acoustic geometry embedded within the background flow. Characteristic features of such sonic geometry depend on the black hole spin. Such dependence can be probed by studying the correlation of the acoustic surface gravity [Formula: see text] with the Kerr parameter [Formula: see text]. The [Formula: see text]–[Formula: see text] relationship further gets influenced by the geometric configuration of the accretion flow structure. In this work, such influence has been studied for multitransonic shocked accretion where linear perturbation of general relativistic flow profile leads to the formation of two analogue black hole-type horizons formed at the sonic points and one analogue white hole-type horizon which is formed at the shock location producing divergent acoustic surface gravity. Dependence of the [Formula: see text]–[Formula: see text] relationship on the geometric configuration has also been studied for monotransonic accretion, over the entire span of the Kerr parameter including retrograde flow. For accreting astrophysical black holes, the present work thus investigates how the salient features of the embedded relativistic sonic geometry may be determined not only by the background spacetime, but also by the flow configuration of the embedding matter.

InP-based optical switch module operating through carrier-induced refractive index change

1990 ◽  
Vol 29 (3) ◽  
pp. 191 ◽  
Author(s):  
Takeshi Kato ◽  
Hiroaki Inoue ◽  
Yasushi Takahashi ◽  
Koji K. Ishida
Keyword(s):  
Refractive Index ◽  
Optical Switch ◽  
Refractive Index Change ◽  
Index Change ◽  
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