The Light Velocity Casimir Effect
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Computational Characterization of the Wave Propagation Behaviour of Multi-Stable Periodic Cellular Materials∗
Computational Characterization of the Wave Propagation Behaviour of Multi-Stable Periodic Cellular Materials∗ Camilo Valencia1, David Restrepo2,4, Nilesh D. Mankame3, Pablo D. Zavattieri 2y , and Juan Gomez 1z 1Civil Engineering Department, Universidad EAFIT, Medell´ın,050022, Colombia 2Lyles School of Civil Engineering, Purdue University, West Lafayette, IN 47907, USA 3Vehicle Systems Research Laboratory, General Motors Global Research & Development, Warren, MI 48092, USA. 4Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX 78249, USA Abstract In this work, we present a computational analysis of the planar wave propagation behavior of a one-dimensional periodic multi-stable cellular material. Wave propagation in these ma- terials is interesting because they combine the ability of periodic cellular materials to exhibit stop and pass bands with the ability to dissipate energy through cell-level elastic instabilities. Here, we use Bloch periodic boundary conditions to compute the dispersion curves and in- troduce a new approach for computing wide band directionality plots. Also, we deconstruct the wave propagation behavior of this material to identify the contributions from its various structural elements by progressively building the unit cell, structural element by element, from a simple, homogeneous, isotropic primitive. Direct integration time domain analyses of a representative volume element at a few salient frequencies in the stop and pass bands are used to confirm the existence of partial band gaps in the response of the cellular material. Insights gained from the above analyses are then used to explore modifications of the unit cell that allow the user to tune the band gaps in the response of the material. -
Path Integrals in Quantum Mechanics
Path Integrals in Quantum Mechanics Dennis V. Perepelitsa MIT Department of Physics 70 Amherst Ave. Cambridge, MA 02142 Abstract We present the path integral formulation of quantum mechanics and demon- strate its equivalence to the Schr¨odinger picture. We apply the method to the free particle and quantum harmonic oscillator, investigate the Euclidean path integral, and discuss other applications. 1 Introduction A fundamental question in quantum mechanics is how does the state of a particle evolve with time? That is, the determination the time-evolution ψ(t) of some initial | i state ψ(t ) . Quantum mechanics is fully predictive [3] in the sense that initial | 0 i conditions and knowledge of the potential occupied by the particle is enough to fully specify the state of the particle for all future times.1 In the early twentieth century, Erwin Schr¨odinger derived an equation specifies how the instantaneous change in the wavefunction d ψ(t) depends on the system dt | i inhabited by the state in the form of the Hamiltonian. In this formulation, the eigenstates of the Hamiltonian play an important role, since their time-evolution is easy to calculate (i.e. they are stationary). A well-established method of solution, after the entire eigenspectrum of Hˆ is known, is to decompose the initial state into this eigenbasis, apply time evolution to each and then reassemble the eigenstates. That is, 1In the analysis below, we consider only the position of a particle, and not any other quantum property such as spin. 2 D.V. Perepelitsa n=∞ ψ(t) = exp [ iE t/~] n ψ(t ) n (1) | i − n h | 0 i| i n=0 X This (Hamiltonian) formulation works in many cases. -
Curiens Principle and Spontaneous Symmetry Breaking
Curie’sPrinciple and spontaneous symmetry breaking John Earman Department of History and Philosophy of Science, University of Pittsburgh, Pittsburgh, PA, USA Abstract In 1894 Pierre Curie announced what has come to be known as Curie’s Principle: the asymmetry of e¤ects must be found in their causes. In the same publication Curie discussed a key feature of what later came to be known as spontaneous symmetry breaking: the phenomena generally do not exhibit the symmetries of the laws that govern them. Philosophers have long been interested in the meaning and status of Curie’s Principle. Only comparatively recently have they begun to delve into the mysteries of spontaneous symmetry breaking. The present paper aims to advance the dis- cussion of both of these twin topics by tracing their interaction in classical physics, ordinary quantum mechanics, and quantum …eld theory. The fea- tures of spontaneous symmetry that are peculiar to quantum …eld theory have received scant attention in the philosophical literature. These features are highlighted here, along with a explanation of why Curie’sPrinciple, though valid in quantum …eld theory, is nearly vacuous in that context. 1. Introduction The statement of what is now called Curie’sPrinciple was announced in 1894 by Pierre Curie: (CP) When certain e¤ects show a certain asymmetry, this asym- metry must be found in the causes which gave rise to it (Curie 1894, p. 401).1 This principle is vague enough to allow some commentators to see in it pro- found truth while others see only falsity (compare Chalmers 1970; Radicati 1987; van Fraassen 1991, pp. -
The Zig-Zag Road to Reality 1 Introduction
The zig-zag road to reality Author Colin, S, Wiseman, HM Published 2011 Journal Title Journal of Physics A: Mathematical and Theoretical DOI https://doi.org/10.1088/1751-8113/44/34/345304 Copyright Statement © 2011 Institute of Physics Publishing. This is the author-manuscript version of this paper. Reproduced in accordance with the copyright policy of the publisher.Please refer to the journal's website for access to the definitive, published version. Downloaded from http://hdl.handle.net/10072/42701 Griffith Research Online https://research-repository.griffith.edu.au The zig-zag road to reality S Colin1;2;y and H M Wiseman1;z 1 Centre for Quantum Dynamics, Griffith University, Brisbane, QLD 4111, Australia. 2 Perimeter Institute for Theoretical Physics, 31 Caroline Street North, ON N2L2Y5, Waterloo, Canada. E-mail: [email protected], [email protected] Abstract In the standard model of particle physics, all fermions are fundamentally massless and only acquire their effective bare mass when the Higgs field condenses. Therefore, in a fundamental de Broglie-Bohm pilot-wave quan- tum field theory (valid before and after the Higgs condensation), position beables should be attributed to massless fermions. In our endeavour to build a pilot-wave theory of massless fermions, which would be relevant for the study of quantum non-equilibrium in the early universe, we are naturally led to Weyl spinors and to particle trajectories which give mean- ing to the `zig-zag' picture of the electron discussed recently by Penrose. We show that a positive-energy massive Dirac electron of given helicity can be thought of as a superposition of positive and negative energy Weyl particles of the same helicity and that a single massive Dirac electron can in principle move luminally at all times. -
Vector Wave Propagation Method Ein Beitrag Zum Elektromagnetischen Optikrechnen
Vector Wave Propagation Method Ein Beitrag zum elektromagnetischen Optikrechnen Inauguraldissertation zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften der Universitat¨ Mannheim vorgelegt von Dipl.-Inf. Matthias Wilhelm Fertig aus Mannheim Mannheim, 2011 Dekan: Prof. Dr.-Ing. Wolfgang Effelsberg Universitat¨ Mannheim Referent: Prof. Dr. rer. nat. Karl-Heinz Brenner Universitat¨ Heidelberg Korreferent: Prof. Dr.-Ing. Elmar Griese Universitat¨ Siegen Tag der mundlichen¨ Prufung:¨ 18. Marz¨ 2011 Abstract Based on the Rayleigh-Sommerfeld diffraction integral and the scalar Wave Propagation Method (WPM), the Vector Wave Propagation Method (VWPM) is introduced in the thesis. It provides a full vectorial and three-dimensional treatment of electromagnetic fields over the full range of spatial frequen- cies. A model for evanescent modes from [1] is utilized and eligible config- urations of the complex propagation vector are identified to calculate total internal reflection, evanescent coupling and to maintain the conservation law. The unidirectional VWPM is extended to bidirectional propagation of vectorial three-dimensional electromagnetic fields. Totally internal re- flected waves and evanescent waves are derived from complex Fresnel coefficients and the complex propagation vector. Due to the superposition of locally deformed plane waves, the runtime of the WPM is higher than the runtime of the BPM and therefore an efficient parallel algorithm is de- sirable. A parallel algorithm with a time-complexity that scales linear with the number of threads is presented. The parallel algorithm contains a mini- mum sequence of non-parallel code which possesses a time complexity of the one- or two-dimensional Fast Fourier Transformation. The VWPM and the multithreaded VWPM utilize the vectorial version of the Plane Wave Decomposition (PWD) in homogeneous medium without loss of accuracy to further increase the simulation speed. -
Some Remarks About Mass and Zitterbewegung Substructure Of
Some remarks about mass and Zitterbewegung substructure of electron P. Brovetto†, V. Maxia† and M. Salis†‡ (1) †On leave from Istituto Nazionale di Fisica della Materia - Cagliari, Italy ‡Dipartimento di Fisica - Universit`adi Cagliari, Italy Abstract - It is shown that the electron Zitterbewegung, that is, the high- frequency microscopic oscillatory motion of electron about its centre of mass, originates a spatial distribution of charge. This allows the point-like electron behave like a particle of definite size whose self-energy, that is, energy of its electromagnetic field, owns a finite value. This has implications for the electron mass, which, in principle, might be derived from Zitterbewegung physics. Key words - Elementary particle masses, Zitterbewegung theory. Introduction The nature of mass of elementary particles is one of the most intriguing top- ics in modern physics. Electron deserves a special attention because, differently from quarks which are bound in composite objects (adrons), it is a free parti- cle. Moreover, differently from neutrinos whose vanishingly small mass is still controversial, its mass is a well-known quantity. At the beginning of the past century, the question of the nature of elec- tron mass was debated on the ground of the electromagnetic theory by various authors (Abraham, Lorentz, Poincar´e). Actually, the electron charge e origi- nates in the surrounding space an electromagnetic field −→E, −→H, associated with energy density E2 + H2 /8π and momentum density −→E −→H /4πc. These × densities, when integrated over the space, account for electron self-energy and inertial mass. However, peculiar models must be introduced in order to avoid divergent results. -
ABSTRACT Investigation Into Compactified Dimensions: Casimir
ABSTRACT Investigation into Compactified Dimensions: Casimir Energies and Phenomenological Aspects Richard K. Obousy, Ph.D. Chairperson: Gerald B. Cleaver, Ph.D. The primary focus of this dissertation is the study of the Casimir effect and the possibility that this phenomenon may serve as a mechanism to mediate higher dimensional stability, and also as a possible mechanism for creating a small but non- zero vacuum energy density. In chapter one we review the nature of the quantum vacuum and discuss the different contributions to the vacuum energy density arising from different sectors of the standard model. Next, in chapter two, we discuss cosmology and the introduction of the cosmological constant into Einstein's field equations. In chapter three we explore the Casimir effect and study a number of mathematical techniques used to obtain a finite physical result for the Casimir energy. We also review the experiments that have verified the Casimir force. In chapter four we discuss the introduction of extra dimensions into physics. We begin by reviewing Kaluza Klein theory, and then discuss three popular higher dimensional models: bosonic string theory, large extra dimensions and warped extra dimensions. Chapter five is devoted to an original derivation of the Casimir energy we derived for the scenario of a higher dimensional vector field coupled to a scalar field in the fifth dimension. In chapter six we explore a range of vacuum scenarios and discuss research we have performed regarding moduli stability. Chapter seven explores a novel approach to spacecraft propulsion we have proposed based on the idea of manipulating the extra dimensions of string/M theory. -
Quantum Field Theory*
Quantum Field Theory y Frank Wilczek Institute for Advanced Study, School of Natural Science, Olden Lane, Princeton, NJ 08540 I discuss the general principles underlying quantum eld theory, and attempt to identify its most profound consequences. The deep est of these consequences result from the in nite number of degrees of freedom invoked to implement lo cality.Imention a few of its most striking successes, b oth achieved and prosp ective. Possible limitation s of quantum eld theory are viewed in the light of its history. I. SURVEY Quantum eld theory is the framework in which the regnant theories of the electroweak and strong interactions, which together form the Standard Mo del, are formulated. Quantum electro dynamics (QED), b esides providing a com- plete foundation for atomic physics and chemistry, has supp orted calculations of physical quantities with unparalleled precision. The exp erimentally measured value of the magnetic dip ole moment of the muon, 11 (g 2) = 233 184 600 (1680) 10 ; (1) exp: for example, should b e compared with the theoretical prediction 11 (g 2) = 233 183 478 (308) 10 : (2) theor: In quantum chromo dynamics (QCD) we cannot, for the forseeable future, aspire to to comparable accuracy.Yet QCD provides di erent, and at least equally impressive, evidence for the validity of the basic principles of quantum eld theory. Indeed, b ecause in QCD the interactions are stronger, QCD manifests a wider variety of phenomena characteristic of quantum eld theory. These include esp ecially running of the e ective coupling with distance or energy scale and the phenomenon of con nement. -
THE STRONG INTERACTION by J
MISN-0-280 THE STRONG INTERACTION by J. R. Christman 1. Abstract . 1 2. Readings . 1 THE STRONG INTERACTION 3. Description a. General E®ects, Range, Lifetimes, Conserved Quantities . 1 b. Hadron Exchange: Exchanged Mass & Interaction Time . 1 s 0 c. Charge Exchange . 2 d L u 4. Hadron States a. Virtual Particles: Necessity, Examples . 3 - s u - S d e b. Open- and Closed-Channel States . 3 d n c. Comparison of Virtual and Real Decays . 4 d e 5. Resonance Particles L0 a. Particles as Resonances . .4 b. Overview of Resonance Particles . .5 - c. Resonance-Particle Symbols . 6 - _ e S p p- _ 6. Particle Names n T Y n e a. Baryon Names; , . 6 b. Meson Names; G-Parity, T , Y . 6 c. Evolution of Names . .7 d. The Berkeley Particle Data Group Hadron Tables . 7 7. Hadron Structure a. All Hadrons: Possible Exchange Particles . 8 b. The Excited State Hypothesis . 8 c. Quarks as Hadron Constituents . 8 Acknowledgments. .8 Project PHYSNET·Physics Bldg.·Michigan State University·East Lansing, MI 1 2 ID Sheet: MISN-0-280 THIS IS A DEVELOPMENTAL-STAGE PUBLICATION Title: The Strong Interaction OF PROJECT PHYSNET Author: J. R. Christman, Dept. of Physical Science, U. S. Coast Guard The goal of our project is to assist a network of educators and scientists in Academy, New London, CT transferring physics from one person to another. We support manuscript Version: 11/8/2001 Evaluation: Stage B1 processing and distribution, along with communication and information systems. We also work with employers to identify basic scienti¯c skills Length: 2 hr; 12 pages as well as physics topics that are needed in science and technology. -
A Discussion on Characteristics of the Quantum Vacuum
A Discussion on Characteristics of the Quantum Vacuum Harold \Sonny" White∗ NASA/Johnson Space Center, 2101 NASA Pkwy M/C EP411, Houston, TX (Dated: September 17, 2015) This paper will begin by considering the quantum vacuum at the cosmological scale to show that the gravitational coupling constant may be viewed as an emergent phenomenon, or rather a long wavelength consequence of the quantum vacuum. This cosmological viewpoint will be reconsidered on a microscopic scale in the presence of concentrations of \ordinary" matter to determine the impact on the energy state of the quantum vacuum. The derived relationship will be used to predict a radius of the hydrogen atom which will be compared to the Bohr radius for validation. The ramifications of this equation will be explored in the context of the predicted electron mass, the electrostatic force, and the energy density of the electric field around the hydrogen nucleus. It will finally be shown that this perturbed energy state of the quan- tum vacuum can be successfully modeled as a virtual electron-positron plasma, or the Dirac vacuum. PACS numbers: 95.30.Sf, 04.60.Bc, 95.30.Qd, 95.30.Cq, 95.36.+x I. BACKGROUND ON STANDARD MODEL OF COSMOLOGY Prior to developing the central theme of the paper, it will be useful to present the reader with an executive summary of the characteristics and mathematical relationships central to what is now commonly referred to as the standard model of Big Bang cosmology, the Friedmann-Lema^ıtre-Robertson-Walker metric. The Friedmann equations are analytic solutions of the Einstein field equations using the FLRW metric, and Equation(s) (1) show some commonly used forms that include the cosmological constant[1], Λ. -
Quantum Vacuum Energy Density and Unifying Perspectives Between Gravity and Quantum Behaviour of Matter
Annales de la Fondation Louis de Broglie, Volume 42, numéro 2, 2017 251 Quantum vacuum energy density and unifying perspectives between gravity and quantum behaviour of matter Davide Fiscalettia, Amrit Sorlib aSpaceLife Institute, S. Lorenzo in Campo (PU), Italy corresponding author, email: [email protected] bSpaceLife Institute, S. Lorenzo in Campo (PU), Italy Foundations of Physics Institute, Idrija, Slovenia email: [email protected] ABSTRACT. A model of a three-dimensional quantum vacuum based on Planck energy density as a universal property of a granular space is suggested. This model introduces the possibility to interpret gravity and the quantum behaviour of matter as two different aspects of the same origin. The change of the quantum vacuum energy density can be considered as the fundamental medium which determines a bridge between gravity and the quantum behaviour, leading to new interest- ing perspectives about the problem of unifying gravity with quantum theory. PACS numbers: 04. ; 04.20-q ; 04.50.Kd ; 04.60.-m. Key words: general relativity, three-dimensional space, quantum vac- uum energy density, quantum mechanics, generalized Klein-Gordon equation for the quantum vacuum energy density, generalized Dirac equation for the quantum vacuum energy density. 1 Introduction The standard interpretation of phenomena in gravitational fields is in terms of a fundamentally curved space-time. However, this approach leads to well known problems if one aims to find a unifying picture which takes into account some basic aspects of the quantum theory. For this reason, several authors advocated different ways in order to treat gravitational interaction, in which the space-time manifold can be considered as an emergence of the deepest processes situated at the fundamental level of quantum gravity. -
The Massless Two-Loop Two-Point Function and Zeta Functions in Counterterms of Feynman Diagrams
The Massless Two-loop Two-point Function and Zeta Functions in Counterterms of Feynman Diagrams Dissertation zur Erlangung des Grades \Doktor der Naturwissenschaften" am Fachbereich Physik der Johannes-Gutenberg-Universit¨at in Mainz Isabella Bierenbaum geboren in Landau/Pfalz Mainz, Februar 2005 Datum der mundlic¨ hen Prufung:¨ 6. Juni 2005 D77 (Diss. Universit¨at Mainz) Contents 1 Introduction 1 2 Renormalization 3 2.1 General introduction . 3 2.2 Feynman diagrams and power counting . 5 2.3 Dimensional regularization . 9 2.4 Counterterms . 10 2.4.1 One-loop diagrams . 10 2.4.2 Multi-loop diagrams . 11 3 Hopf and Lie algebra 15 3.1 The Hopf algebras HR and HF G . 15 3.1.1 The Hopf algebra of rooted trees HR . 16 3.1.2 The Hopf algebra of Feynman graphs HF G . 20 3.1.3 Correspondence between HR, HF G, and ZFF . 20 3.2 Lie algebras . 24 4 The massless two-loop two-point function | an overview 27 4.1 General remarks . 27 4.2 Integer exponents νi | the triangle relation . 29 4.3 Non-integer exponents νi . 32 5 Nested sums 37 5.1 Nested sums . 38 5.1.1 From polylogarithms to multiple polylogarithms . 38 5.1.2 Algebraic relations: shuffle and quasi-shuffle . 41 5.2 nestedsums | the theory and some of its functions . 45 5.2.1 nestedsums | the general idea . 46 5.2.2 nestedsums | the four classes of functions . 48 6 The massless two-loop two-point function 53 6.1 The expansion of I^(2;5) . 53 6.1.1 Decomposition of I^(2;5) .