scholarly journals Transport properties of a class of electromagnetic waves

2007 ◽  
Vol 34 (2) ◽  
pp. 161-171
Author(s):  
David Christie
Keyword(s):  
Transport Properties ◽  
Electromagnetic Waves ◽  
Transport Equations ◽  
Space Time ◽  
Wkb Approximation ◽  
Curved Space ◽  
Dependent Transport ◽  
Relationship Of ◽  
The Relationship

We demonstrate that in many cases, known frame-dependent transport equations for a propagating electromagnetic 2-form in an arbitrarily curved space-time can be replaced by a much simpler set of frame-independent equations. The frame-dependent equations can then be more easily recovered from the simpler set presented here if required. The relationship of such transport equations to the WKB approximation is also briefly discussed.

scholarly journals Broadband Terahertz Spectroscopy of Phonon-Polariton Dispersion in Ferroelectrics

Photonics ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 55 ◽  
Author(s):  
Seiji Kojima
Keyword(s):  
Electromagnetic Waves ◽  
Terahertz Spectroscopy ◽  
Far Infrared ◽  
Longitudinal Optical ◽  
Vibrational Modes ◽  
Terahertz Time Domain Spectroscopy ◽  
Raman Scattering Spectroscopy ◽  
Longitudinal Optical Mode ◽  
Relationship Of ◽  
The Relationship

Electromagnetic waves at frequencies below the X-ray region strongly couple to the optical vibrational modes in a solid. These coupled excitations have been called phonon polaritons. The relationship of the polariton frequency versus the polariton wavevector shows a remarkable dispersion, especially in the vicinity of the transverse and longitudinal optical mode frequencies. The significant frequency dependence enables valuable applications such as a tunable terahertz radiation source. The polariton dispersion relations of technologically important dielectric and ferroelectric crystals were reviewed in the broad terahertz range using terahertz time-domain spectroscopy, far-infrared spectroscopy, and Raman scattering spectroscopy.

GRAVITATIONAL ANOMALY AND THE WORLD TOPOLOGY

1992 ◽  
Vol 07 (01) ◽  
pp. 33-42 ◽  
Author(s):  
ASHIM ROY ◽  
PRATUL BANDYOPADHYAY
Keyword(s):  
Space Time ◽  
Quantum Geometry ◽  
Gravitational Anomaly ◽  
Quantization Procedure ◽  
The World ◽  
Relationship Of ◽  
The Relationship

Here it is shown that the gravitational anomaly is compensated by the torsion term in the Einstein–Cartan action when the geometrical and topological origin of torsion is considered in the context of quantum geometry characterizing the quantization procedure of a fermion. The relationship of this anomaly with Pontryagin index is then established. The relevance of this index in the origin of topological fixtures like wormholes in space-time has also been discussed.

The concept of order I. The space-time structure

1954 ◽  
Vol 50 (2) ◽  
pp. 278-286 ◽  
Author(s):  
E. W. Bastin ◽  
C. W. Kilmister
Keyword(s):  
Physical World ◽  
Space Time ◽  
Time Structure ◽  
Electromagnetic Structure ◽  
Space Time Structure ◽  
Relationship Of ◽  
The Relationship

ABSTRACTEven if ideas of measurement did not exist, a great deal of the simple mechanical and electromagnetic structure of the physical world could be understood. To see how this can be so, the orthodox ideas of the relationship of mathematics to physics are inadequate. In this paper a development of this fundamental non-metrical physics is made to depend on a different view of this relationship.

scholarly journals الذاكرة في المجموعة القصصية (يسقط المطر.. تموت الأميرة) لمنى الشمري / Memory in the anthology of stories (The rain falls.. The Princess passes away) by Mona Shammari

2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Hannan Ghāzi Al-Muṭairī
Keyword(s):  
Short Story ◽  
Analytical Method ◽  
Cultural Awareness ◽  
Space Time ◽  
The Past ◽  
Relationship Of ◽  
The Relationship

ملخص البحث: يسعى هذا البحث إلى عرض ملامح الذاكرة عند القاصة منى الشمري في مجموعتها القصصية (يسقط المطر.. تموت الأميرة) بوصفها منجزاً في رسم صورة الذاكرة عبر المكان والزمن والشخصية واللغة، فكل هذه العناصر السابقة شكلت أدوات وظفتها القاصة وعبرت من خلالها عن صور الذاكرة التي برزت من خلال أربعة محاور كالآتي: الذاكرة والمكان، الذاكرة والزمن، الذاكرة والشخصية، الذاكرة واللغة. يقوم البحث وفق المنهج الوصفي التحليلي، ومن النتائج التي خلص إليها البحث: شكلت منطقة (الفحيحيل) دور البطولة عبر المجموعة القصصية؛ إذ كانت مسرحاً لأحداث القصص، كما أن علاقة الذاكرة بالزمن تتوقف على موقف الشخصية من هذا الزمن، كما تسعى الشخصيات للاحتفاظ بالأشياء التي تذكرها بالماضي في محاولة لتعويض الحنين، وقد شكلت اللغة الوعاء الثقافي الذي سجلت من خلاله القاصة ذاكرة الماضي. الكلمات المفتاحية: الذاكرة -الحنين إلى الماضي -القصة القصيرة-منى الشمري– الكويت.   Abstract: This research seeks to present the features of memory in the story series of Mona Al-Shammari (The Rain Falls..The Princess Passes Away) as an achievement in drawing the image of memory through space, time, personality and language. All of these previous elements have   used as tools for capturing the memory images that have emerged through four axes: memory and space, memory and time, memory and personality, memory and language. The research   conducted according to the descriptive analytical method. The research found the following results: Fahaheel represented the role of heroism through the story series as it was the scene of storytelling, and the relationship of memory in time depends on the personality position of this time. The characters also try to retain the things they remember in the past in an attempt to compensate nostalgia. The language formed the cultural awareness through which the story recorded the past. Keywords: Memory- nostalgia- short story - Mona Shammari - Kuwait.   Abstrak Kajian ini berusaha untuk memaparkan ciri-ciri memori dalam antologi cerita nukilan Mona Al-Shammari (Hujan turun..Puteri mangkat) sebagai satu pencapaian dalam melakarkan imej memori melalui ruang, masa, watak dan bahasa. Semua unsur-unsur yang lepas telah digunakan sebagai alat untuk mencerap imej-imej memori yang telah muncul dalam empat dimensi: memori dan ruang, memori dan masa, memori dan watak serta memori dan bahasa. Kajian ini dilaksanakan secara deskriptif dan analitikal. Kajian ini mendapati: Fahaleel mewakili watak hero dalam rangkaian cerita-cerita tersebut kerana ia adalah merupakan latar penceritaan cerita; hubungan memori dalam masa bergantung kepada kedudukan watak di dalam masa tersebut. Watak-watak tersebut juga cuba mengekalkan apa yang diingati mereka pada masa lampau sebagai satu usaha untuk menggantikan nostalgia. Bahasa pula dilihat membentuk kesedaran budaya melalui masa lampau yang dirakamkan oleh cerita. Kata kunci: Memori, nostalgia, cerpen, Mona Shammari, Kuwait

scholarly journals Propagation of high-frequency electromagnetic waves through a magnetized plasma in curved space-time. I

1980 ◽  
Vol 370 (1742) ◽  
pp. 389-406 ◽  
Keyword(s):  
Partial Differential Equations ◽  
Differential Equations ◽  
High Frequency ◽  
Electromagnetic Waves ◽  
Space Time ◽  
Magnetized Plasma ◽  
Asymptotic Solutions ◽  
Perturbation Equation ◽  
Partial Differential ◽  
Curved Space

This is the first of two papers on the propagation of high-frequency electromagnetic waves through a magnetized plasma in curved space-time. We first show that the nonlinear system of equations governing the plasma and the electromagnetic field in a given, external gravitational field has locally a unique solution for any initial data set obeying the appropriate constraints, and that this system is linearization stable at any of its solu­tions. Next we prove that the linearized perturbations of a ‘background’ solution are characterized by a third-order (not strictly) hyperbolic, constraint-free system of three partial differential equations for three unknown functions of the four space-time coordinates. We generalize the algorithm for obtaining oscillatory asymptotic solutions of linear systems of partial differential equations of arbitrary order, depending polynomially on a small parameter such that it applies to the previously established perturbation equation when the latter is rewritten in terms of dimensionless variables and a small scale ratio. For hyperbolic systems we then state a sufficient condition in order that asymptotic solutions of finite order, constructed as usual by means of a Hamiltonian system of ordinary differential equations for the characteristic strips and a system of transport equations determining the propagation of the amplitudes along the rays, indeed approximate solutions of the system. The pro­cedure is a special case of a two-scale method, suitable for describing the propagation of locally approximately plane, monochromatic waves through a dispersive, inhomogeneous medium. In the second part we shall apply the general method to the perturbation equation referred to above.

Propagation of high-frequency electromagnetic waves through a magnetized plasma in curved space-time. II. Application of the asymptotic approximation

1981 ◽  
Vol 374 (1756) ◽  
pp. 65-86 ◽  
Keyword(s):  
High Frequency ◽  
Electromagnetic Waves ◽  
Polarization State ◽  
Space Time ◽  
Magnetized Plasma ◽  
Curved Space ◽  
Polarized Waves ◽  
Background Magnetic Field ◽  
Linearly Polarized ◽  
Unmagnetized Plasma

This is the second of two papers on the propagation of high-frequency electromagnetic waves through an inhomogeneous, non-stationary plasma in curved space-time. By applying the general two-scale W.K.B. method developed in part I to the basic wave equation, derived also in that paper, we here obtain the dispersion relation, the rays, the polarization states and the transport laws for the amplitudes of these waves. In an unmagnetized plasma the transport preserves the helicity and the eccentricity of the polarization state along each ray; the axes of the polarization ellipse rotate along a ray, relative to quasiparallely displaced directions, at a rate determined by the vorticity of the electron fluid; and the norm of the amplitude changes according to a conservation law which can be interpreted as the constancy of the number of quasiphotons. In a magnetized plasma the polarization state changes differently for ordinary and extraordinary waves, according to the angle between the wavenormal and the background magnetic field, and under specified approximation conditions the direction of polarization of linearly polarized waves undergoes a generalized Faraday rotation.

A Stage Presence: Michael Kirby’s Embedded Sculptures

2017 ◽  
Vol 61 (2) ◽  
pp. 105-116
Author(s):  
Alexander Streitberger
Keyword(s):  
Performance Art ◽  
Theoretical Concept ◽  
Space Time ◽  
Relationship Of ◽  
The Relationship

Well-known for his writing on Happenings, performance art, and avantgarde theatre, Michael Kirby also produced a series of highly notable photo-sculptures. Developed in conjunction with the theoretical concept of “situational aesthetics,” these “embedded sculptures” were conceived of as “visual instruments” that explored the relationship of space, time, context, and beholder.

The Relationship of Transport Properties and 1HNMR Spectra to the Structure of Molten Methylpyridinium Halides

1981 ◽  
Vol 128 (11) ◽  
pp. 2331-2336 ◽  
Author(s):  
David S. Newman ◽  
Rick R. Rhinebarger ◽  
David Siconolfi ◽  
Olumuyiwa A. Banjoko
Keyword(s):  
Transport Properties ◽  
Relationship Of ◽  
The Relationship
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