scholarly journals An introduction to gravitational waves through electrodynamics: a quadrupole comparison

2021 ◽  
Author(s):  
Glauber Carvalho Dorsch ◽  
Lucas Emanuel Antunes Porto
Keyword(s):  
Electromagnetic Radiation ◽  
Gravitational Waves ◽  
Quadrupole Moment ◽  
Radiation Emission ◽  
Transverse Modes ◽  
Stellar Formation ◽  
The Stability

Abstract We present a pedagogical introduction to some key computations in gravitational waves via a side-by-side comparison with the quadrupole contribution of electromagnetic radiation. Subtleties involving gauge choices and projections over transverse modes in the tensorial theory are made clearer by direct analogy with the vectorial counterpart. The power emitted by the quadrupole moment in both theories is computed, and the similarities as well as the origins of eventual discrepancies are discussed. Finally, we analyze the stability of bound systems under radiation emission, and discuss how the strength of the interactions can be established this way. We use the results to impose an anthropic bound on Newton's constant of order G < 3×104 Gobs, which is on par with similar constraints from stellar formation.

Optimum Multi-Nozzle Configuration for Minimizing the Rayleigh Integral During High-Frequency Transverse Instabilities

2021 ◽  
Author(s):  
Vishal Acharya ◽  
Tim Lieuwen
Keyword(s):  
High Frequency ◽  
Transverse Mode ◽  
Acoustic Mode ◽  
Combustion Stability ◽  
Circular Distribution ◽  
Transverse Modes ◽  
Fixed Set ◽  
Circular Configuration ◽  
Swirling Strength ◽  
The Stability

Abstract This paper develops a formalism for optimizing nozzle location/configuration with respect to combustion stability of high-frequency transverse modes in a can combustor. The stability of these acoustically non-compact flames was assessed using the Rayleigh Integral (RI). Several key control parameters influence RI - flame angle, swirling strength, nozzle location, as well as nozzle location with respect to the acoustic mode shape. In this study, we consider a N-around-1 configuration such as typically used in a multi-nozzle can system and study the overall stability of this system for different natural transverse modes. Typically, such nozzles are distributed in a uniformly circular manner for which we study the overall RI and for cases where RI&gt;0, we optimize the nozzle distribution that can reduce and minimize RI. For a fixed geometry such a circular configuration, the analysis shows how the flame's parameters must vary across the different nozzles, to result in a relatively stable system. Additionally, for a fixed set of flame parameters, the analysis also indicates the non-circular distribution of the N nozzles that minimizes RI. Overall, the analysis aims to provide insights on designing nozzle locations around the center nozzle for minimal amplification of a given transverse mode.

scholarly journals COHERENT THZ ELECTROMAGNETIC RADIATION EMISSION AS A SHOCK WAVE DIAGNOSTIC AND PROBE OF ULTRAFAST PHASE TRANSFORMATIONS

2009 ◽  
Author(s):  
Evan J. Reed ◽  
Michael R. Armstrong ◽  
Ki-Yong Kim ◽  
James H. Glownia ◽  
William M. Howard ◽  
...  
Keyword(s):  
Shock Wave ◽  
Electromagnetic Radiation ◽  
Phase Transformations ◽  
Radiation Emission

Method of Far-field Electromagnetic Radiation Prediction and Suppression Based on Equivalence of Capacitance Parameters in Power Converter System

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Li Zhengzhi ◽  
B Zhang Kaiyan ◽  
Wang Shishan ◽  
A Guo Jian
Keyword(s):  
Electromagnetic Radiation ◽  
Research Area ◽  
Power Converter ◽  
Path Model ◽  
Scattering Parameter ◽  
Radiation Emission ◽  
Current Path ◽  
Key Issues ◽  
Magnetic Ring ◽  
Good Agreement

Electromagnetic radiation is one of the key issues in research area of EMC. This paper analyzes that common-mode (CM) current is the main noise source, and transmits through parasitic capacitances between input cables and ground, thus CM current path model (CCP) is established. Moreover, CCP is formed as equivalent prediction model of radiation (EMR) by appropriate simplification. The parasitic capacitances of EMR are extracted, and EMR is iterative designed. Furthermore, the radiation emission of two models is in good agreement. At last, ferrite magnetic ring is selected to change scattering parameter matrix, thus electromagnetic radiation can be suppressed; the recommended installation of magnetic ring is given. Keywords: Radiation; Parasitic Parameter;

Stability of relativistic transverse cold plasma waves. Part 2. Linearly polarized waves

1979 ◽  
Vol 22 (2) ◽  
pp. 201-222 ◽  
Author(s):  
F. J. Romeiras
Keyword(s):  
Nonlinear Wave ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Transverse Modes ◽  
Electron Positron ◽  
Polarized Waves ◽  
Linearly Polarized ◽  
Linear Differential ◽  
Unmagnetized Plasma ◽  
The Stability

This is part 2 of a paper concerned with the stability against small perturbations of a certain class of nonlinear wave solutions of the equations that describe a cold unmagnetized plasma. It refers to transverse linearly polarized waves in an electron-positron plasma. A numerical method, based on Floquet's theory of linear differential equations with periodic coefficients, is used to solve the perturbation equations and obtain the instability growth rates. All the three possible types of perturbations are discussed for a typical value of the (large) amplitude of the nonlinear wave: electrically longitudinal slightly unstable modes (with maximum growth rate γ approximately equal to 0·07ω0, where ω0is the frequency of the nonlinear wave); purely transverse moderately unstable modes (with γ ≃ 0·26ω0); and highly unstable electrically transverse modes (with γ ≃ l·5ω0).

Detecting Blackholes through Gravitational Waves

2014 ◽  
Author(s):  
Charles D. Bailyn
Keyword(s):  
Black Holes ◽  
General Relativity ◽  
Electromagnetic Radiation ◽  
Gravitational Waves ◽  
Gravitational Radiation ◽  
Stellar Mass ◽  
Supermassive Black Holes ◽  
Current Technology

This chapter looks at the detection of black holes through gravitational waves. While further improvements can be expected in the ability to detect and measure electromagnetic radiation, it is possible that the next great advances in observational astrophysics will come from the detection of other kinds of information altogether. Currently, there is a great excitement about the possibility of directly detecting an entirely new “celestial messenger,” namely, gravitational radiation. The existence of gravitational waves is a prediction of general relativity, and current technology is very close to being able to detect them directly. The strongest sources of gravitational radiation are expected to be merging black holes. Since such mergers are expected to occur, both between stellar-mass and supermassive black holes, the detection of gravitational radiation would provide a new way not only to explore gravitational physics but also to look for and to study celestial black holes.

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