Catoni F., Et Al. the Mathematics of Minkowski Space-Time.. With
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Old-Fashioned Relativity & Relativistic Space-Time Coordinates
Relativistic Coordinates-Classic Approach 4.A.1 Appendix 4.A Relativistic Space-time Coordinates The nature of space-time coordinate transformation will be described here using a fictional spaceship traveling at half the speed of light past two lighthouses. In Fig. 4.A.1 the ship is just passing the Main Lighthouse as it blinks in response to a signal from the North lighthouse located at one light second (about 186,000 miles or EXACTLY 299,792,458 meters) above Main. (Such exactitude is the result of 1970-80 work by Ken Evenson's lab at NIST (National Institute of Standards and Technology in Boulder) and adopted by International Standards Committee in 1984.) Now the speed of light c is a constant by civil law as well as physical law! This came about because time and frequency measurement became so much more precise than distance measurement that it was decided to define the meter in terms of c. Fig. 4.A.1 Ship passing Main Lighthouse as it blinks at t=0. This arrangement is a simplified model for a 1Hz laser resonator. The two lighthouses use each other to maintain a strict one-second time period between blinks. And, strict it must be to do relativistic timing. (Even stricter than NIST is the universal agency BIGANN or Bureau of Intergalactic Aids to Navigation at Night.) The simulations shown here are done using RelativIt. Relativistic Coordinates-Classic Approach 4.A.2 Fig. 4.A.2 Main and North Lighthouses blink each other at precisely t=1. At p recisel y t=1 sec. -
The Emergence of Gravitational Wave Science: 100 Years of Development of Mathematical Theory, Detectors, Numerical Algorithms, and Data Analysis Tools
BULLETIN (New Series) OF THE AMERICAN MATHEMATICAL SOCIETY Volume 53, Number 4, October 2016, Pages 513–554 http://dx.doi.org/10.1090/bull/1544 Article electronically published on August 2, 2016 THE EMERGENCE OF GRAVITATIONAL WAVE SCIENCE: 100 YEARS OF DEVELOPMENT OF MATHEMATICAL THEORY, DETECTORS, NUMERICAL ALGORITHMS, AND DATA ANALYSIS TOOLS MICHAEL HOLST, OLIVIER SARBACH, MANUEL TIGLIO, AND MICHELE VALLISNERI In memory of Sergio Dain Abstract. On September 14, 2015, the newly upgraded Laser Interferometer Gravitational-wave Observatory (LIGO) recorded a loud gravitational-wave (GW) signal, emitted a billion light-years away by a coalescing binary of two stellar-mass black holes. The detection was announced in February 2016, in time for the hundredth anniversary of Einstein’s prediction of GWs within the theory of general relativity (GR). The signal represents the first direct detec- tion of GWs, the first observation of a black-hole binary, and the first test of GR in its strong-field, high-velocity, nonlinear regime. In the remainder of its first observing run, LIGO observed two more signals from black-hole bina- ries, one moderately loud, another at the boundary of statistical significance. The detections mark the end of a decades-long quest and the beginning of GW astronomy: finally, we are able to probe the unseen, electromagnetically dark Universe by listening to it. In this article, we present a short historical overview of GW science: this young discipline combines GR, arguably the crowning achievement of classical physics, with record-setting, ultra-low-noise laser interferometry, and with some of the most powerful developments in the theory of differential geometry, partial differential equations, high-performance computation, numerical analysis, signal processing, statistical inference, and data science. -
Hyperbolic Geometry
Flavors of Geometry MSRI Publications Volume 31,1997 Hyperbolic Geometry JAMES W. CANNON, WILLIAM J. FLOYD, RICHARD KENYON, AND WALTER R. PARRY Contents 1. Introduction 59 2. The Origins of Hyperbolic Geometry 60 3. Why Call it Hyperbolic Geometry? 63 4. Understanding the One-Dimensional Case 65 5. Generalizing to Higher Dimensions 67 6. Rudiments of Riemannian Geometry 68 7. Five Models of Hyperbolic Space 69 8. Stereographic Projection 72 9. Geodesics 77 10. Isometries and Distances in the Hyperboloid Model 80 11. The Space at Infinity 84 12. The Geometric Classification of Isometries 84 13. Curious Facts about Hyperbolic Space 86 14. The Sixth Model 95 15. Why Study Hyperbolic Geometry? 98 16. When Does a Manifold Have a Hyperbolic Structure? 103 17. How to Get Analytic Coordinates at Infinity? 106 References 108 Index 110 1. Introduction Hyperbolic geometry was created in the first half of the nineteenth century in the midst of attempts to understand Euclid’s axiomatic basis for geometry. It is one type of non-Euclidean geometry, that is, a geometry that discards one of Euclid’s axioms. Einstein and Minkowski found in non-Euclidean geometry a This work was supported in part by The Geometry Center, University of Minnesota, an STC funded by NSF, DOE, and Minnesota Technology, Inc., by the Mathematical Sciences Research Institute, and by NSF research grants. 59 60 J. W. CANNON, W. J. FLOYD, R. KENYON, AND W. R. PARRY geometric basis for the understanding of physical time and space. In the early part of the twentieth century every serious student of mathematics and physics studied non-Euclidean geometry. -
Unifying the Hyperbolic and Spherical 2-Body Problem with Biquaternions
Unifying the Hyperbolic and Spherical 2-Body Problem with Biquaternions Philip Arathoon December 2020 Abstract The 2-body problem on the sphere and hyperbolic space are both real forms of holo- morphic Hamiltonian systems defined on the complex sphere. This admits a natural description in terms of biquaternions and allows us to address questions concerning the hyperbolic system by complexifying it and treating it as the complexification of a spherical system. In this way, results for the 2-body problem on the sphere are readily translated to the hyperbolic case. For instance, we implement this idea to completely classify the relative equilibria for the 2-body problem on hyperbolic 3-space for a strictly attractive potential. Background and outline The case of the 2-body problem on the 3-sphere has recently been considered by the author in [1]. This treatment takes advantage of the fact that S3 is a group and that the action of SO(4) on S3 is generated by the left and right multiplication of S3 on itself. This allows for a reduction in stages, first reducing by the left multiplication, and then reducing an intermediate space by the residual right-action. An advantage of this reduction-by-stages is that it allows for a fairly straightforward derivation of the relative equilibria solutions: the relative equilibria may first be classified in the intermediate reduced space and then reconstructed on the original phase space. For the 2-body problem on hyperbolic space the same idea does not apply. Hyperbolic 3-space H3 cannot be endowed with an isometric group structure and the symmetry group SO(1; 3) does not arise as a direct product of two groups. -
An Analysis of Spacetime Numbers
Rowan University Rowan Digital Works Theses and Dissertations 4-30-1999 An analysis of spacetime numbers Nicolae Andrew Borota Rowan University Follow this and additional works at: https://rdw.rowan.edu/etd Recommended Citation Borota, Nicolae Andrew, "An analysis of spacetime numbers" (1999). Theses and Dissertations. 1771. https://rdw.rowan.edu/etd/1771 This Thesis is brought to you for free and open access by Rowan Digital Works. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of Rowan Digital Works. For more information, please contact [email protected]. AN ANALYSIS OF SPACETIME NUMBERS by Nicolae Andrew Borota A Thesis Submitted in partial fulfillment of the requirements of the Masters of Arts Degree of The Graduate School at Rowan University 04/30/99 Approved by Date Approved A/P/ i- 30 /F?7 ABSTRACT Nicolae Andrew Borota An Analysis of Spacetime Numbers 1999 Thesis Mathematics The familiar complex numbers begin by considering the solution to the equation i = -1, which is not a real number. A two-dimensional number system arises of the form z = x + iy. Spacetime numbers are based upon the simple relation j = 1, with the corresponding two-dimensional number system z = x + jt. It seems odd that anything useful can come from this simple idea, since the solutions of our j equation are the familiar real numbers +1 and -1. However, many interesting applications arise from these new numbers. The most useful aspect of spacetime numbers is in solving problems in the areas of special and general relativity. These areas deal with the notion of space-time, hence the name "spacetime numbers." My goal is to explain in a direct, yet simple manner, the use of these special numbers. -
The Universe of General Relativity, Springer 2005.Pdf
Einstein Studies Editors: Don Howard John Stachel Published under the sponsorship of the Center for Einstein Studies, Boston University Volume 1: Einstein and the History of General Relativity Don Howard and John Stachel, editors Volume 2: Conceptual Problems of Quantum Gravity Abhay Ashtekar and John Stachel, editors Volume 3: Studies in the History of General Relativity Jean Eisenstaedt and A.J. Kox, editors Volume 4: Recent Advances in General Relativity Allen I. Janis and John R. Porter, editors Volume 5: The Attraction of Gravitation: New Studies in the History of General Relativity John Earman, Michel Janssen and John D. Norton, editors Volume 6: Mach’s Principle: From Newton’s Bucket to Quantum Gravity Julian B. Barbour and Herbert Pfister, editors Volume 7: The Expanding Worlds of General Relativity Hubert Goenner, Jürgen Renn, Jim Ritter, and Tilman Sauer, editors Volume 8: Einstein: The Formative Years, 1879–1909 Don Howard and John Stachel, editors Volume 9: Einstein from ‘B’ to ‘Z’ John Stachel Volume 10: Einstein Studies in Russia Yuri Balashov and Vladimir Vizgin, editors Volume 11: The Universe of General Relativity A.J. Kox and Jean Eisenstaedt, editors A.J. Kox Jean Eisenstaedt Editors The Universe of General Relativity Birkhauser¨ Boston • Basel • Berlin A.J. Kox Jean Eisenstaedt Universiteit van Amsterdam Observatoire de Paris Instituut voor Theoretische Fysica SYRTE/UMR8630–CNRS Valckenierstraat 65 F-75014 Paris Cedex 1018 XE Amsterdam France The Netherlands AMS Subject Classification (2000): 01A60, 83-03, 83-06 Library of Congress Cataloging-in-Publication Data The universe of general relativity / A.J. Kox, editors, Jean Eisenstaedt. p. -
On Bivectors and Jay-Vectors - 2 - M
Ricerche di Matematica (2019) 68, 859–882. https://doi.org/10.1007/s11587-019-00442-2 On bivectors and jay-vectors M. Hayes School of Mechanical and Materials Engineering, University College, Dublin N. H. Scott∗ School of Mathematics, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ Received: 5 February 2019 Revised: 25 March 2019 Published: 6 April 2019 · · Note from the second author. This is joint work with my erstwhile PhD supervisor at the University of East Anglia, Norwich, Professor Mike Hayes, late of University College Dublin. Since Mike’s unfortunate death I have endeavoured to finish the work in a man- ner he would have approved of. This paper is dedicated to Colette Hayes, Mike’s widow. Abstract A combination a+ib where i2 = 1 and a, b are real vectors is called a bivector. − Gibbs developed a theory of bivectors, in which he associated an ellipse with each bivector. He obtained results relating pairs of conjugate semi-diameters and in particular considered the implications of the scalar product of two bivectors being zero. This paper is an attempt to develop a similar formulation for hyperbolas by the use of jay-vectors — a jay-vector is a linear combination a +jb of real vectors a and b, where j2 = +1 but j is not a real number, so j = 1. The implications 6 ± of the vanishing of the scalar product of two jay-vectors is also considered. We show how to generate a triple of conjugate semi-diameters of an ellipsoid from any arXiv:2004.14154v1 [math.GM] 27 Apr 2020 orthonormal triad. -
Hyperbolic Functions∗
Hyperbolic functions∗ Attila M´at´e Brooklyn College of the City University of New York November 30, 2020 Contents 1 Hyperbolic functions 1 2 Connection with the unit hyperbola 2 2.1 Geometricmeaningoftheparameter . ......... 3 3 Complex exponentiation: connection with trigonometric functions 3 3.1 Trigonometric representation of complex numbers . ............... 4 3.2 Extending the exponential function to complex numbers. ................ 5 1 Hyperbolic functions The hyperbolic functions are defined as follows ex e−x ex + e−x sinh x ex e−x sinh x = − , cosh x = , tanh x = = − 2 2 cosh x ex + e−x 1 2 sech x = = , ... cosh x ex + e−x The following formulas are easy to establish: (1) cosh2 x sinh2 x = 1, sech2 x = 1 tanh2 x, − − sinh(x + y) = sinh x cosh y + cosh x sinh y cosh(x + y) = cosh x cosh y + sinh x sinh y; the analogy with trigonometry is clear. The differentiation formulas also show a lot of similarity: ′ ′ (sinh x) = cosh x, (cosh x) = sinh x, ′ ′ (tanh x) = sech2 x = 1 tanh2 x, (sech x) = tanh x sech x. − − Hyperbolic functions can be used instead of trigonometric substitutions to evaluate integrals with quadratic expressions under the square root. For example, to evaluate the integral √x2 1 − dx Z x2 ∗Written for the course Mathematics 1206 at Brooklyn College of CUNY. 1 for x > 0, we can use the substitution x = cosh t with t 0.1 We have √x2 1 = sinh t and dt = sinh xdx, and so ≥ − √x2 1 sinh t − dx = sinh tdt = tanh2 tdt = (1 sech2 t) dt = t tanh t + C. -
On the Formal Consistency of Theory and Experiment, with Applications
On the Formal Consistency of Theory and Experiment, with Applications to Problems in the Initial-Value Formulation of the Partial-Differential Equations of Mathematical Physicsy DRAFT Erik Curielz June 9, 2011 yThis paper is a corrected and clarified version of Curiel (2005), which itself is in the main a distillation of the much lengthier, more detailed and more technical Curiel (2004). I make frequent reference to that paper throughout this one, primarily for the statement, elaboration and proof of technical results omitted here. zI would like to thank someone for help with this paper, but I can't. 1 Theory and Experiment Abstract The dispute over the viability of various theories of relativistic, dissipative fluids is an- alyzed. The focus of the dispute is identified as the question of determining what it means for a theory to be applicable to a given type of physical system under given con- ditions. The idea of a physical theory's regime of propriety is introduced, in an attempt to clarify the issue, along with the construction of a formal model trying to make the idea precise. This construction involves a novel generalization of the idea of a field on spacetime, as well as a novel method of approximating the solutions to partial-differential equations on relativistic spacetimes in a way that tries to account for the peculiar needs of the interface between the exact structures of mathematical physics and the inexact data of experimental physics in a relativistically invariant way. It is argued, on the ba- sis of these constructions, that the idea of a regime of propriety plays a central role in attempts to understand the semantical relations between theoretical and experimental knowledge of the physical world in general, and in particular in attempts to explain what it may mean to claim that a physical theory models or represents a kind of physical system. -
Appendix A: the Present-Day Meaning of Geometry
Appendix A: The Present-day Meaning of Geometry …… effringere ut arta Rerum Naturae portarum claustra cupiret. De Rerum Natura (I, 70–71) The 19th century is today known as the century of industrial revolution but equally important is the revolution in mathematics and physics, that took place in 18th and 19th centuries. Actually we can say that the industrial revolution arises from the important technical and scientific progresses. As far as the mathematics is concerned a lot of new arguments appeared, and split a matter that, for more than twenty centuries, has been represented by Euclidean geometry also considered, following Plato and Galileo, as the language for the measure and interpretation of the Nature. Practically the differential calculus, complex numbers, analytic, differential and non-Euclidean geometries, the functions of a complex variable, partial differential equations and group theory emerged and were formalized. Now we briefly see that many of these mathematical arguments are derived as an extension or a criticism of Euclidean geometry. In both cases the conclusion is a complete validation of the logical and operative cogency of Euclidean geometry. Finally a reformulation of the finalization of Euclidean geometry has been made, so that also the ‘‘new geometries’’ are, today, considered in an equivalent way since they all fit with the general definition: Geometry is the study of the invariant properties of figures or, in an equivalent way a geometric property is one shared by all congruent figures. There are many ways to state the congruency (equivalence) between figures, here we recall one that allows us the extensions considered in this book. -
The Historical Origins of Spacetime Scott Walter
The Historical Origins of Spacetime Scott Walter To cite this version: Scott Walter. The Historical Origins of Spacetime. Abhay Ashtekar, V. Petkov. The Springer Handbook of Spacetime, Springer, pp.27-38, 2014, 10.1007/978-3-662-46035-1_2. halshs-01234449 HAL Id: halshs-01234449 https://halshs.archives-ouvertes.fr/halshs-01234449 Submitted on 26 Nov 2015 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. The historical origins of spacetime Scott A. Walter Chapter 2 in A. Ashtekar and V. Petkov (eds), The Springer Handbook of Spacetime, Springer: Berlin, 2014, 27{38. 2 Chapter 2 The historical origins of spacetime The idea of spacetime investigated in this chapter, with a view toward un- derstanding its immediate sources and development, is the one formulated and proposed by Hermann Minkowski in 1908. Until recently, the principle source used to form historical narratives of Minkowski's discovery of space- time has been Minkowski's own discovery account, outlined in the lecture he delivered in Cologne, entitled \Space and time" [1]. Minkowski's lecture is usually considered as a bona fide first-person narrative of lived events. Ac- cording to this received view, spacetime was a natural outgrowth of Felix Klein's successful project to promote the study of geometries via their char- acteristic groups of transformations. -
Chapter 2 Euclidean and Hyperbolic Geometry
Classical Geometries in Modern Walter Benz Contexts Geometry of Real Inner Product Spaces Birkhäuser Verlag Basel • Boston • Berlin Authors: Walter Benz Fachbereich Mathematik Universität Hamburg Bundesstr. 55 20146 Hamburg Germany e-mail: [email protected] 2000 Mathematical Subject Classification 39B52, 51B10, 51B25, 51M05, 51M10, 83C20 A CIP catalogue record for this book is available from the Library of Congress, Washington D.C., USA Bibliographic information published by Die Deutsche Bibliothek Die Deutsche Bibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data is available in the Internet at <http://dnb.ddb.de>. ISBN 3-7643-7371-7 Birkhäuser Verlag, Basel – Boston – Berlin This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, re-use of illustrations, recitation, broadcast- ing, reproduction on microfilms or in other ways, and storage in data banks. For any kind of use permission of the copyright owner must be obtained. © 2005 Birkhäuser Verlag, P.O. Box 133, CH-4010 Basel, Switzerland Part of Springer Science+Business Media Cover design: Micha Lotrovsky, CH-4106 Therwil, Switzerland Printed on acid-free paper produced from chlorine-free pulp. TCF °° Printed in Germany ISBN-10: 3-7643-7371-7 e-ISBN: 3-7643-7432-2 ISBN-13: 978-3-7643-7371-9 9 8 7 6 5 4 3 2 1 www.birkhauser.ch Contents Preface ix 1 Translation Groups 1 1.1Realinnerproductspaces....................... 1 1.2Examples................................ 2 1.3 Isomorphic, non-isomorphic spaces . 3 1.4InequalityofCauchy–Schwarz..................... 4 1.5 Orthogonal mappings .