Differential Geometry of Curves and Surfaces, Second Edition 2Nd Edition Pdf, Epub, Ebook
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Toponogov.V.A.Differential.Geometry
Victor Andreevich Toponogov with the editorial assistance of Vladimir Y. Rovenski Differential Geometry of Curves and Surfaces A Concise Guide Birkhauser¨ Boston • Basel • Berlin Victor A. Toponogov (deceased) With the editorial assistance of: Department of Analysis and Geometry Vladimir Y. Rovenski Sobolev Institute of Mathematics Department of Mathematics Siberian Branch of the Russian Academy University of Haifa of Sciences Haifa, Israel Novosibirsk-90, 630090 Russia Cover design by Alex Gerasev. AMS Subject Classification: 53-01, 53Axx, 53A04, 53A05, 53A55, 53B20, 53B21, 53C20, 53C21 Library of Congress Control Number: 2005048111 ISBN-10 0-8176-4384-2 eISBN 0-8176-4402-4 ISBN-13 978-0-8176-4384-3 Printed on acid-free paper. c 2006 Birkhauser¨ Boston All rights reserved. This work may not be translated or copied in whole or in part without the writ- ten permission of the publisher (Birkhauser¨ Boston, c/o Springer Science+Business Media Inc., 233 Spring Street, New York, NY 10013, USA) and the author, except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and re- trieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use in this publication of trade names, trademarks, service marks and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. Printed in the United States of America. (TXQ/EB) 987654321 www.birkhauser.com Contents Preface ....................................................... vii About the Author ............................................. -
Geometry of Curves
Appendix A Geometry of Curves “Arc, amplitude, and curvature sustain a similar relation to each other as time, motion and velocity, or as volume, mass and density.” Carl Friedrich Gauss The rest of this lecture notes is about geometry of curves and surfaces in R2 and R3. It will not be covered during lectures in MATH 4033 and is not essential to the course. However, it is recommended for readers who want to acquire workable knowledge on Differential Geometry. A.1. Curvature and Torsion A.1.1. Regular Curves. A curve in the Euclidean space Rn is regarded as a function r(t) from an interval I to Rn. The interval I can be finite, infinite, open, closed n n or half-open. Denote the coordinates of R by (x1, x2, ... , xn), then a curve r(t) in R can be written in coordinate form as: r(t) = (x1(t), x2(t),..., xn(t)). One easy way to make sense of a curve is to regard it as the trajectory of a particle. At any time t, the functions x1(t), x2(t), ... , xn(t) give the coordinates of the particle in n R . Assuming all xi(t), where 1 ≤ i ≤ n, are at least twice differentiable, then the first derivative r0(t) represents the velocity of the particle, its magnitude jr0(t)j is the speed of the particle, and the second derivative r00(t) represents the acceleration of the particle. As a course on Differential Manifolds/Geometry, we will mostly study those curves which are infinitely differentiable (i.e. -
Extended Rectifying Curves As New Kind of Modified Darboux Vectors
TWMS J. Pure Appl. Math., V.9, N.1, 2018, pp.18-31 EXTENDED RECTIFYING CURVES AS NEW KIND OF MODIFIED DARBOUX VECTORS Y. YAYLI1, I. GOK¨ 1, H.H. HACISALIHOGLU˘ 1 Abstract. Rectifying curves are defined as curves whose position vectors always lie in recti- fying plane. The centrode of a unit speed curve in E3 with nonzero constant curvature and non-constant torsion (or nonzero constant torsion and non-constant curvature) is a rectifying curve. In this paper, we give some relations between non-helical extended rectifying curves and their Darboux vector fields using any orthonormal frame along the curves. Furthermore, we give some special types of ruled surface. These surfaces are formed by choosing the base curve as one of the integral curves of Frenet vector fields and the director curve δ as the extended modified Darboux vector fields. Keywords: rectifying curve, centrodes, Darboux vector, conical geodesic curvature. AMS Subject Classification: 53A04, 53A05, 53C40, 53C42 1. Introduction From elementary differential geometry it is well known that at each point of a curve α, its planes spanned by fT;Ng, fT;Bg and fN; Bg are known as the osculating plane, the rectifying plane and the normal plane, respectively. A curve called twisted curve has non-zero curvature functions in the Euclidean 3-space. Rectifying curves are introduced by B. Y. Chen in [3] as space curves whose position vector always lies in its rectifying plane, spanned by the tangent and the binormal vector fields T and B of the curve. Accordingly, the position vector with respect to some chosen origin, of a rectifying curve α in E3, satisfies the equation α(s) = λ(s)T (s) + µ(s)B(s) for some functions λ(s) and µ(s): He proved that a twisted curve is congruent to a rectifying τ curve if and only if the ratio { is a non-constant linear function of arclength s: Subsequently Ilarslan and Nesovic generalized the rectifying curves in Euclidean 3-space to Euclidean 4-space [10]. -
Arxiv:0911.0334V2 [Gr-Qc] 4 Jul 2020
Classical Physics: Spacetime and Fields Nikodem Poplawski Department of Mathematics and Physics, University of New Haven, CT, USA Preface We present a self-contained introduction to the classical theory of spacetime and fields. This expo- sition is based on the most general principles: the principle of general covariance (relativity) and the principle of least action. The order of the exposition is: 1. Spacetime (principle of general covariance and tensors, affine connection, curvature, metric, tetrad and spin connection, Lorentz group, spinors); 2. Fields (principle of least action, action for gravitational field, matter, symmetries and conservation laws, gravitational field equations, spinor fields, electromagnetic field, action for particles). In this order, a particle is a special case of a field existing in spacetime, and classical mechanics can be derived from field theory. I dedicate this book to my Parents: Bo_zennaPop lawska and Janusz Pop lawski. I am also grateful to Chris Cox for inspiring this book. The Laws of Physics are simple, beautiful, and universal. arXiv:0911.0334v2 [gr-qc] 4 Jul 2020 1 Contents 1 Spacetime 5 1.1 Principle of general covariance and tensors . 5 1.1.1 Vectors . 5 1.1.2 Tensors . 6 1.1.3 Densities . 7 1.1.4 Contraction . 7 1.1.5 Kronecker and Levi-Civita symbols . 8 1.1.6 Dual densities . 8 1.1.7 Covariant integrals . 9 1.1.8 Antisymmetric derivatives . 9 1.2 Affine connection . 10 1.2.1 Covariant differentiation of tensors . 10 1.2.2 Parallel transport . 11 1.2.3 Torsion tensor . 11 1.2.4 Covariant differentiation of densities . -
ON the CURVATURES of a CURVE in RIEMANN SPACE*F
ON THE CURVATURES OF A CURVE IN RIEMANN SPACE*f BY E,. H. CUTLER Introduction. The curvature and torsion of a curve in ordinary space have three properties which it is the purpose of this paper to attempt to extend to the curvatures of a curve in Riemann space. First, if the curvature vanishes identically the curve is a straight line ; if the torsion vanishes identically the curve lies in a plane. Second, the distances of a point of the curve from the tangent line and the osculating plane at a nearby point are given approxi- mately by formulas involving the curvature and torsion. Third, the curva- ture of a curve at a point is the curvature of its projection on the osculating plane at the point. In extending to Riemann space we take as the Riemannian analogue of the line or plane, a geodesic space generated by geodesies through a point. Such a space possesses the property of the line or plane of being de- termined by the proper number of directions given at a point, but it will not in general have the three properties given above. On the other hand, if we take as the analogue of line or plane only totally geodesic spaces, then, if such osculating "planes" exist, the three properties will hold. Curves with a vanishing curvature. Given a curve C: xi = x'(s), i = l, •••,«, in a Riemann space Vn with fundamental tensor g,-,-(assumed defi- nite). Following BlaschkeJ we write the Frenet formulas for the curve. The « associate vectors are given by ¿x* dx' (1) Éi|' = —> fcl'./T" = &-i|4 ('=1. -
Extension of the Darboux Frame Into Euclidean 4-Space and Its Invariants
Turkish Journal of Mathematics Turk J Math (2017) 41: 1628 { 1639 http://journals.tubitak.gov.tr/math/ ⃝c TUB¨ ITAK_ Research Article doi:10.3906/mat-1604-56 Extension of the Darboux frame into Euclidean 4-space and its invariants Mustafa DULD¨ UL¨ 1;∗, Bahar UYAR DULD¨ UL¨ 2, Nuri KURUOGLU˘ 3, Ertu˘grul OZDAMAR¨ 4 1Department of Mathematics, Faculty of Science and Arts, Yıldız Technical University, Istanbul,_ Turkey 2Department of Mathematics Education, Faculty of Education, Yıldız Technical University, Istanbul,_ Turkey 3Department of Civil Engineering, Faculty of Engineering and Architecture, Geli¸simUniversity, Istanbul,_ Turkey 4Department of Mathematics, Faculty of Science and Arts, Uluda˘gUniversity, Bursa, Turkey Received: 13.04.2016 • Accepted/Published Online: 14.02.2017 • Final Version: 23.11.2017 Abstract: In this paper, by considering a Frenet curve lying on an oriented hypersurface, we extend the Darboux frame field into Euclidean 4-space E4 . Depending on the linear independency of the curvature vector with the hypersurface's normal, we obtain two cases for this extension. For each case, we obtain some geometrical meanings of new invariants along the curve on the hypersurface. We also give the relationships between the Frenet frame curvatures and Darboux frame curvatures in E4 . Finally, we compute the expressions of the new invariants of a Frenet curve lying on an implicit hypersurface. Key words: Curves on hypersurface, Darboux frame field, curvatures 1. Introduction In differential geometry, frame fields constitute an important tool while studying curves and surfaces. The most familiar frame fields are the Frenet{Serret frame along a space curve, and the Darboux frame along a surface curve. -
Research Article Weyl-Invariant Extension of the Metric-Affine Gravity
CORE Metadata, citation and similar papers at core.ac.uk Provided by Open Access Repository Hindawi Publishing Corporation Advances in High Energy Physics Volume 2015, Article ID 902396, 7 pages http://dx.doi.org/10.1155/2015/902396 Research Article Weyl-Invariant Extension of the Metric-Affine Gravity R. Vazirian,1 M. R. Tanhayi,2 and Z. A. Motahar3 1 Plasma Physics Research Center, Islamic Azad University, Science and Research Branch, Tehran 1477893855, Iran 2Department of Physics, Islamic Azad University, Central Tehran Branch, Tehran 8683114676, Iran 3Department of Physics, University of Malaya, 50603 Kuala Lumpur, Malaysia Correspondence should be addressed to M. R. Tanhayi; [email protected] Received 30 September 2014; Accepted 28 November 2014 Academic Editor: Anastasios Petkou Copyright © 2015 R. Vazirian et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The publication of this article was funded by SCOAP3. Metric-affine geometry provides a nontrivial extension of the general relativity where the metric and connection are treated as the two independent fundamental quantities in constructing the spacetime (with nonvanishing torsion and nonmetricity). In this paper,westudythegenericformofactioninthisformalismandthenconstructtheWeyl-invariantversionofthistheory.Itisshown that, in Weitzenbock¨ space, the obtained Weyl-invariant action can cover the conformally invariant teleparallel action. Finally, the related field equations are obtained in the general case. 1. Introduction with the metric and torsion-free condition is relaxed; thus, in addition to Christoffel symbols, the affine connection would Extended theories of gravity have become a field of interest contain an antisymmetric part and nonmetric terms as well. -
Spacetime and Geometry: an Introduction to General Relativity Pdf, Epub, Ebook
SPACETIME AND GEOMETRY: AN INTRODUCTION TO GENERAL RELATIVITY PDF, EPUB, EBOOK Sean M. Carroll,John E. Neely,Richard R. Kibbe | 513 pages | 28 Sep 2003 | Pearson Education (US) | 9780805387322 | English | New Jersey, United States Spacetime and Geometry: An Introduction to General Relativity PDF Book Likewise an explorer from region IV could have a brief look at region I before perishing. Mathematics Kronecker delta Levi-Civita symbol metric tensor nonmetricity tensor Christoffel symbols Ricci curvature Riemann curvature tensor Weyl tensor torsion tensor. Thorne, John Archibald Wheeler Gravitation. When using coordinate transformations as described above, the new coordinate system will often appear to have oblique axes compared to the old system. Indeed, they find some remarkable new regions of spacetime! In general relativity, gravity can be regarded as not a force but a consequence of a curved spacetime geometry where the source of curvature is the stress—energy tensor representing matter, for instance. Views Read Edit View history. Modern cosmological models are a bit more complicated, but retain those features. I was misled even lied to by JG on math. Bitte versuchen Sie es erneut. Considering the number of things I did not know it was a good idea to postpone reading this section until now. Tuesday, 25 February Einstein's equation. So I decided to test the flatness idea in two dimensions Principles of Cosmology and Gravitation. It was supposed to be impossible to travel between regions I and IV of the Kruskal diagram and here Carroll -
J.M. Sullivan, TU Berlin A: Curves Diff Geom I, SS 2019 This Course Is an Introduction to the Geometry of Smooth Curves and Surf
J.M. Sullivan, TU Berlin A: Curves Diff Geom I, SS 2019 This course is an introduction to the geometry of smooth if the velocity never vanishes). Then the speed is a (smooth) curves and surfaces in Euclidean space Rn (in particular for positive function of t. (The cusped curve β above is not regular n = 2; 3). The local shape of a curve or surface is described at t = 0; the other examples given are regular.) in terms of its curvatures. Many of the big theorems in the DE The lengthR [ : Länge] of a smooth curve α is defined as subject – such as the Gauss–Bonnet theorem, a highlight at the j j len(α) = I α˙(t) dt. (For a closed curve, of course, we should end of the semester – deal with integrals of curvature. Some integrate from 0 to T instead of over the whole real line.) For of these integrals are topological constants, unchanged under any subinterval [a; b] ⊂ I, we see that deformation of the original curve or surface. Z b Z b We will usually describe particular curves and surfaces jα˙(t)j dt ≥ α˙(t) dt = α(b) − α(a) : locally via parametrizations, rather than, say, as level sets. a a Whereas in algebraic geometry, the unit circle is typically be described as the level set x2 + y2 = 1, we might instead This simply means that the length of any curve is at least the parametrize it as (cos t; sin t). straight-line distance between its endpoints. Of course, by Euclidean space [DE: euklidischer Raum] The length of an arbitrary curve can be defined (following n we mean the vector space R 3 x = (x1;:::; xn), equipped Jordan) as its total variation: with with the standard inner product or scalar product [DE: P Xn Skalarproduktp ] ha; bi = a · b := aibi and its associated norm len(α):= TV(α):= sup α(ti) − α(ti−1) : jaj := ha; ai. -
Appendix Computer Formulas ▼
▲ Appendix Computer Formulas ▼ The computer commands most useful in this book are given in both the Mathematica and Maple systems. More specialized commands appear in the answers to several computer exercises. For each system, we assume a famil- iarity with how to access the system and type into it. In recent versions of Mathematica, the core commands have generally remained the same. By contrast, Maple has made several fundamental changes; however most older versions are still recognized. For both systems, users should be prepared to adjust for minor changes. Mathematica 1. Fundamentals Basic features of Mathematica are as follows: (a) There are no prompts or termination symbols—except that a final semicolon suppresses display of the output. Input (new or old) is acti- vated by the command Shift-return (or Shift-enter), and the input and resulting output are numbered. (b) Parentheses (. .) for algebraic grouping, brackets [. .] for arguments of functions, and braces {. .} for lists. (c) Built-in commands typically spelled in full—with initials capitalized— and then compressed into a single word. Thus it is preferable for user- defined commands to avoid initial capitals. (d) Multiplication indicated by either * or a blank space; exponents indi- cated by a caret, e.g., x^2. For an integer n only, nX = n*X,where X is not an integer. 451 452 Appendix: Computer Formulas (e) Single equal sign for assignments, e.g., x = 2; colon-equal (:=) for deferred assignments (evaluated only when needed); double equal signs for mathematical equations, e.g., x + y == 1. (f) Previous outputs are called up by either names assigned by the user or %n for the nth output. -
Lecture Note on Elementary Differential Geometry
Lecture Note on Elementary Differential Geometry Ling-Wei Luo* Institute of Physics, Academia Sinica July 20, 2019 Abstract This is a note based on a course of elementary differential geometry as I gave the lectures in the NCTU-Yau Journal Club: Interplay of Physics and Geometry at Department of Electrophysics in National Chiao Tung University (NCTU) in Spring semester 2017. The contents of remarks, supplements and examples are highlighted in the red, green and blue frame boxes respectively. The supplements can be omitted at first reading. The basic knowledge of the differential forms can be found in the lecture notes given by Dr. Sheng-Hong Lai (NCTU) and Prof. Jen-Chi Lee (NCTU) on the website. The website address of Interplay of Physics and Geometry is http: //web.it.nctu.edu.tw/~string/journalclub.htm or http://web.it.nctu. edu.tw/~string/ipg/. Contents 1 Curve on E2 ......................................... 1 2 Curve in E3 .......................................... 6 3 Surface theory in E3 ..................................... 9 4 Cartan’s moving frame and exterior differentiation methods .............. 31 1 Curve on E2 We define n-dimensional Euclidean space En as a n-dimensional real space Rn equipped a dot product defined n-dimensional vector space. Tangent vector In 2-dimensional Euclidean space, an( E2 plane,) we parametrize a curve p(t) = x(t); y(t) by one parameter t with re- spect to a reference point o with a fixed Cartesian coordinate frame. The( velocity) vector at point p is given by p_ (t) = x_(t); y_(t) with the norm Figure 1: A curve. p p jp_ (t)j = p_ · p_ = x_ 2 +y _2 ; (1) *Electronic address: [email protected] 1 where x_ := dx/dt. -
On the Patterns of Principal Curvature Lines Around a Curve of Umbilic Points
Anais da Academia Brasileira de Ciências (2005) 77(1): 13–24 (Annals of the Brazilian Academy of Sciences) ISSN 0001-3765 www.scielo.br/aabc On the Patterns of Principal Curvature Lines around a Curve of Umbilic Points RONALDO GARCIA1 and JORGE SOTOMAYOR2 1Instituto de Matemática e Estatística, Universidade Federal de Goiás Caixa Postal 131 – 74001-970 Goiânia, GO, Brasil 2Instituto de Matemática e Estatística, Universidade de São Paulo Rua do Matão 1010, Cidade Universitária, 05508-090 São Paulo, SP, Brasil Manuscript received on June 15, 2004; accepted for publication on October 10, 2004; contributed by Jorge Sotomayor* ABSTRACT In this paper is studied the behavior of principal curvature lines near a curve of umbilic points of a smooth surface. Key words: Umbilic point, principal curvature lines, principal cycles. 1 INTRODUCTION The study of umbilic points on surfaces and the patterns of principal curvature lines around them has attracted the attention of generation of mathematicians among whom can be named Monge, Darboux and Carathéodory. One aspect – concerning isolated umbilics – of the contributions of these authors, departing from Darboux (Darboux 1896), has been elaborated and extended in several directions by Garcia, Sotomayor and Gutierrez, among others. See (Gutierrez and Sotomayor, 1982, 1991, 1998), (Garcia and Sotomayor, 1997, 2000) and (Garcia et al. 2000, 2004) where additional references can be found. In (Carathéodory 1935) Carathéodory mentioned the interest of non isolated umbilics in generic surfaces pertinent to Geometric Optics. In a remarkably concise study he established that any local analytic regular arc of curve in R3 is a curve of umbilic points of a piece of analytic surface.