Ebook Download Matrices and Linear Algebra Pdf Free Download

Total Page:16

File Type:pdf, Size:1020Kb

Ebook Download Matrices and Linear Algebra Pdf Free Download MATRICES AND LINEAR ALGEBRA PDF, EPUB, EBOOK Hans Schneider,George Philip Barker | 432 pages | 01 Nov 1989 | Dover Publications Inc. | 9780486660141 | English | New York, United States Matrices and Linear Algebra PDF Book With the norm in place, absolutely convergent series can be used instead of finite sums. The basic operations of addition, subtraction, scalar multiplication, and transposition can still be defined without problem; however matrix multiplication may involve infinite summations to define the resulting entries, and these are not defined in general. Two tables summarizing the total sales between last month and this month are written to illustrate the amounts. JHU Press. However, the explicit point of view of matrices tends to obfuscate the matter, [76] and the abstract and more powerful tools of functional analysis can be used instead. This implies that for any vectors u , v in V and scalars a , b in F , one has. Hidden categories: Articles with short description Short description is different from Wikidata Articles needing cleanup from August All pages needing cleanup Cleanup tagged articles with a reason field from August Wikipedia pages needing cleanup from August Articles needing cleanup from September Cleanup tagged articles with a reason field from September Wikipedia pages needing cleanup from September Articles to be expanded from September All articles to be expanded Articles using small message boxes Commons category link from Wikidata Wikipedia articles with BNF identifiers Wikipedia articles with GND identifiers Wikipedia articles with LCCN identifiers Wikipedia articles with NDL identifiers. A complete metric space along with the additional structure of an inner product a conjugate symmetric sesquilinear form is known as a Hilbert space , which is in some sense a particularly well-behaved Banach space. September Learn how and when to remove this template message. Also, the trace of a matrix is equal to that of its transpose, that is,. Main article: Linear map. Matrix calculations can be often performed with different techniques. More general types of entries are discussed below. Categories : Matrices. Two-dimensional array of numbers with specific operations. Module homomorphisms between finitely generated free modules may be represented by matrices. This definition makes sense, since this determinant is independent of the choice of the basis. In addition to using upper-case letters to symbolize matrices, many authors use a special typographical style , commonly boldface upright non-italic , to further distinguish matrices from other mathematical objects. There are numerous applications of matrices, both in mathematics and other sciences. For example, calculating the inverse of a matrix via Laplace expansion adj A denotes the adjugate matrix of A. For example, 2-by-2 rotation matrices represent the multiplication with some complex number of absolute value 1, as above. Any two square matrices of the same order can be added and multiplied. The modeling of ambient space is based on geometry. The first four axioms mean that V is an abelian group under addition. For v in V , the map. An empty matrix is a matrix in which the number of rows or columns or both is zero. Properties of matrix addition Opens a modal. Determinant of a 2x2 matrix Opens a modal. Many problems can be solved by both direct algorithms or iterative approaches. Linear algebra is used in almost all areas of mathematics, thus making it relevant in almost all scientific domains that use mathematics. Matrices and Linear Algebra Writer SIAM Review. However, due to the linear nature of matrices, these codes are comparatively easy to break. SIAM Review, 48 3 —, See also stiffness method. It can be proved that two matrices are similar if and only if one can transform one in the other by elementary row and column operations. With the norm in place, absolutely convergent series can be used instead of finite sums. If the matrix entries come from a field, the scalar matrices form a group, under matrix multiplication, that is isomorphic to the multiplicative group of nonzero elements of the field. The set M n , R of all square n -by- n matrices over R is a ring called matrix ring , isomorphic to the endomorphism ring of the left R - module R n. Linear algebra took its modern form in the first half of the twentieth century, when many ideas and methods of previous centuries were generalized as abstract algebra. Van Nostrand, , Google Eprint. Techniques like this are crucial when it comes to the internal dynamics of molecules : the internal vibrations of systems consisting of mutually bound component atoms. Alternatively one can consider only matrices with entries in an algebraically closed field , such as C , from the outset. Frobenius , working on bilinear forms , generalized the theorem to all dimensions Intro to matrix multiplication Opens a modal. Category theory Information theory Mathematical logic Philosophy of mathematics Set theory. Statistics also makes use of matrices in many different forms. Mathematics portal. Main articles: Topological vector space , Normed vector space , and Hilbert space. We use matrices to list data or to represent systems. The interest of all these techniques is that they preserve certain properties of the matrices in question, such as determinant, rank or inverse, so that these quantities can be calculated after applying the transformation, or that certain matrix operations are algorithmically easier to carry out for some types of matrices. Retrieved Matrices and Linear Algebra Reviews Chemistry makes use of matrices in various ways, particularly since the use of quantum theory to discuss molecular bonding and spectroscopy. For linear systems this interaction involves linear functions. Matrices are commonly written in box brackets. Matrices can be used to compactly write and work with multiple linear equations, that is, a system of linear equations. A major branch of numerical analysis is devoted to the development of efficient algorithms for matrix computations, a subject that is centuries old and is today an expanding area of research. Systems of linear equations form a fundamental part of linear algebra. However, every module is a cokernel of a homomorphism of free modules. Kronecker delta Levi-Civita symbol metric tensor nonmetricity tensor Christoffel symbols Ricci curvature Riemann curvature tensor Weyl tensor torsion tensor. If any basis of V and therefore every basis has a finite number of elements, V is a finite-dimensional vector space. Functional analysis applies the methods of linear algebra alongside those of mathematical analysis to study various function spaces; the central objects of study in functional analysis are L p spaces , which are Banach spaces, and especially the L 2 space of square integrable functions, which is the only Hilbert space among them. Quantum mechanics in Hilbert space 2nd ed. Main article: Transpose of a linear map. May Learn how and when to remove this template message. Statistics also makes use of matrices in many different forms. The horizontal and vertical lines of entries in a matrix are called rows and columns , respectively. The identity matrix I n of size n is the n -by- n matrix in which all the elements on the main diagonal are equal to 1 and all other elements are equal to 0, for example,. Mathematics portal. Determinant of a 2x2 matrix. For nonlinear systems , this interaction is often approximated by linear functions. Infinite matrices occur in planetary theory and in atomic theory. Main article: Eigenvalues and eigenvectors. Any two bases of a vector space V have the same cardinality , which is called the dimension of V ; this is the dimension theorem for vector spaces. Partial differential equations can be classified by considering the matrix of coefficients of the highest-order differential operators of the equation. Main article: Row operations. An empty matrix is a matrix in which the number of rows or columns or both is zero. Adding a multiple of any row to another row, or a multiple of any column to another column, does not change the determinant. Matrices and Linear Algebra Read Online The behaviour of many electronic components can be described using matrices. For a matrix representing a linear map from W to V , the row operations correspond to change of bases in V and the column operations correspond to change of bases in W. Its absolute value equals the area in R 2 or volume in R 3 of the image of the unit square or cube , while its sign corresponds to the orientation of the corresponding linear map: the determinant is positive if and only if the orientation is preserved. These subsets are called linear subspaces. Instead, available external libraries provide matrix operations on arrays, in nearly all currently used programming languages. If a basis exists that consists only of eigenvectors, the matrix of f on this basis has a very simple structure: it is a diagonal matrix such that the entries on the main diagonal are eigenvalues, and the other entries are zero. Matrices which have a single row are called row vectors , and those which have a single column are called column vectors. A matrix with the same number of rows and columns, sometimes used to represent a linear transformation from a vector space to itself, such as reflection , rotation , or shearing. The theory of matrices over a ring is similar to that of matrices over a field, except that determinants exist only if the ring is commutative , and that a square matrix over a commutative ring is invertible only if its determinant has a multiplicative inverse in the ring. The blue original is mapped to the green grid and shapes. Crucially, Cayley used a single letter to denote a matrix, thus treating a matrix as an aggregate object. Scalar multiplication is simply multiplying a value through all the elements of a matrix, whereas matrix multiplication is multiplying every element of each row of the first matrix times every element of each column in the second matrix.
Recommended publications
  • 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 .
    [Show full text]
  • 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.
    [Show full text]
  • 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
    [Show full text]
  • Relativistic Spacetime Structure
    Relativistic Spacetime Structure Samuel C. Fletcher∗ Department of Philosophy University of Minnesota, Twin Cities & Munich Center for Mathematical Philosophy Ludwig Maximilian University of Munich August 12, 2019 Abstract I survey from a modern perspective what spacetime structure there is according to the general theory of relativity, and what of it determines what else. I describe in some detail both the “standard” and various alternative answers to these questions. Besides bringing many underexplored topics to the attention of philosophers of physics and of science, metaphysicians of science, and foundationally minded physicists, I also aim to cast other, more familiar ones in a new light. 1 Introduction and Scope In the broadest sense, spacetime structure consists in the totality of relations between events and processes described in a spacetime theory, including distance, duration, motion, and (more gener- ally) change. A spacetime theory can attribute more or less such structure, and some parts of that structure may determine other parts. The nature of these structures and their relations of determi- nation bear on the interpretation of the theory—what the world would be like if the theory were true (North, 2009). For example, the structures of spacetime might be taken as its ontological or conceptual posits, and the determination relations might indicate which of these structures is more fundamental (North, 2018). Different perspectives on these questions might also reveal structural similarities with other spacetime theories, providing the resources to articulate how the picture of the world that that theory provides is different (if at all) from what came before, and might be different from what is yet to come.1 ∗Juliusz Doboszewski, Laurenz Hudetz, Eleanor Knox, J.
    [Show full text]
  • Coframe Geometry, Gravity and Electromagnetism
    IARD2012 IOP Publishing Journal of Physics: Conference Series 437 (2013) 012003 doi:10.1088/1742-6596/437/1/012003 Coframe geometry, gravity and electromagnetism Yakov Itin Institute of Mathematics, Hebrew University of Jerusalem and Jerusalem College of Technology, Jerusalem 91904, Israel E-mail: [email protected] Abstract. The extensions of GR for description of fermions on a curved space, for supergravity, and for the loop quantum gravity ordinary use a set of 16 independent variables instead of 10 components of metric. These variables can be assembled in a coframe field, i.e., a set of four linearly independent 1-forms. In this presentation we review a geometrical structure based on the coframe field. We construct a complete class of the coframe connections which are linear in the first order derivatives of the coframe field on an n dimensional manifolds with and without a metric. The subclasses of the torsion-free, metric-compatible and flat connections are derived. We also study the behavior of the geometrical structures under local transformations of the coframe. The remarkable fact is an existence of a subclass of connections which are invariant when the infinitesimal transformations satisfy the Maxwell-like system of equations. 1. Introduction. Why do we have to go beyond Riemannian geometry? General relativity (GR) is, probably, the best of the known theories of gravity. From mathematical and aesthetic points of view, it can be used as a standard of what a physical theory has to be. Einstein's theory is in a very good agreement with all up-to-date observation data.
    [Show full text]
  • On the Interpretation of the Einstein-Cartan Formalism
    33 On the Interpretation of the Einstein-Cartan Formalism Jobn Staebell 33.1 Introduction Hehl and collaborators [I] have suggested the need to generalize Riemannian ge­ ometry to a metric-affine geometry, by admitting torsion and nonmetricity of the connection field. They assume that this geometry represents the microstructure of space-time, with Riemannian geometry emerging as some sort of macroscopic average over the metric-affine microstructure. They thereby generalize the ear­ lier approach to the Einstein-Cartan formalism of Hehl et al. [2] based on a metric connection with torsion. A particularly clear statement of this point of view is found in Hehl, von der Heyde, and Kerlick [3]: "We claim that the [Einstein-Cartan] field equations ... are, at a classical level, the correct microscopic gravitational field equations. Einstein's field equation ought to be considered a macroscopic phenomenological equation oflimited validity, obtained by averaging [the Einstein-Cartan field equations]" (p. 1067). Adamowicz takes an alternate approach [4], asserting that "the relation between the Einstein-Cartan theory and general relativity is similar to that between the Maxwell theory of continuous media and the classical microscopic electrodynam­ ics" (p. 1203). However, he only develops the idea of treating the spin density that enters the Einstein-Cartan theory as the macroscopic average of microscopic angu­ lar momenta in the linear approximation, and does not make explicit the relation he suggests by developing a formal analogy between quantities in macroscopic electrodynamics and in the Einstein-Cartan theory. In this paper, I shall develop such an analogy with macroscopic electrodynamics in detail for the exact, nonlinear version of the Einstein-Cartan theory.
    [Show full text]
  • A Note on Parallel Transportation in Symmetric Teleparallel Geometry
    A novel approach to autoparallels for the theories of symmetric teleparallel gravity Caglar Pala1∗ and Muzaffer Adak2† , 1 2Department of Physics, Faculty of Arts and Sciences, Pamukkale University, 20017 Denizli, Turkey 1Department of Physics, Faculty of Science, Erciyes University, 38030 Kayseri, Turkey Abstract Although the autoparallel curves and the geodesics coincide in the Riemannian geometry in which only the curvature is nonzero among the nonmetricity, the torsion and the curvature, they define different curves in the non-Riemannian ones. We give a novel approach to autoparallel curves and geodesics for theories of the symmetric teleparallel gravity written in the coincident gauge. PACS numbers: 04.50.Kd, 11.15.Kc, 02.40.Yy Keywords: Non-Riemannian geometry, Geodesic, Autoparallel curve arXiv:1102.1878v2 [physics.gen-ph] 8 Sep 2021 ∗[email protected][email protected] 1 Introduction There have been two main ingredients for the theories of gravity since Isaac Newton; field equations and trajectory equations. The field equations are cast for describing the dynamics of a source and the trajectory ones are the for determining path followed by a spinless massive point test particle. For the Newton’s theory of gravity they are written respectively as ∇2φ =4πGρ (1) d2~r + ∇~ φ =0 (2) dt2 where G is the Newton’s constant of gravity, ~r is the three-dimensional Euclidean position vector of the test particle, t is the time disjoint from the Euclidean space, ρ is the volume density of mass of the source, ∇~ is the gradient operator in the three-dimensional Euclidean space and φ is the gravitational field from a source at the position of ~r.
    [Show full text]
  • Constraining Spacetime Nonmetricity with Neutron Spin Rotation in Liquid
    Physics Letters B 772 (2017) 865–869 Contents lists available at ScienceDirect Physics Letters B www.elsevier.com/locate/physletb Constraining spacetime nonmetricity with neutron spin rotation 4 in liquid He ∗ Ralf Lehnert a,b, , W.M. Snow a,c,d, Zhi Xiao a,e, Rui Xu c a Indiana University Center for Spacetime Symmetries, Bloomington, IN 47405, USA b Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany c Physics Department, Indiana University, Bloomington, IN 47405, USA d Center for Exploration of Energy and Matter, Indiana University, Bloomington, IN 47408, USA e Department of Mathematics and Physics, North China Electric Power University, Beijing 102206, China a r t i c l e i n f o a b s t r a c t Article history: General spacetime nonmetricity coupled to neutrons is studied. In this context, it is shown that certain Received 3 June 2017 nonmetricity components can generate a rotation of the neutron’s spin. Available data on this effect Received in revised form 19 July 2017 obtained from slow-neutron propagation in liquid helium are used to constrain isotropic nonmetricity Accepted 27 July 2017 − (6) components at the level of 10 22 GeV. These results represent the first limit on the nonmetricity ζ S Available online 1 August 2017 2 000 Editor: A. Ringwald parameter as well as the first measurement of nonmetricity inside matter. © 2017 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP3. 1. Introduction The specialized situation in which the nonmetricity tensor van- ishes Nαβγ = 0 and only torsion is nonzero represents the widely The idea that spacetime geometry represents a dynamical phys- known Einstein–Cartan theory [3].
    [Show full text]
  • Appendix a May a Torus with Null Riemann Curvature Exist on E3?
    Appendix A May a Torus with Null Riemann Curvature Exist on E3? 1 1 1 We can also give a flat Riemann curvature tensor for T3 S × S T1 T2. First parametrize 1 2 1 2 3 1 2 1 2 T3 by (x ,x ), x ,x ∈ R, such that its coordinates in R are x(x ,x )=x(x +2π, x +2π)and x(x1,x2)=(h(x1)cosx2,h(x1)sinx2,l(x1), (A.1) with h(x1)=R + r cos x1, l(x1)=r sin x1, (A.2) where here R and r are real positive constants and R>r(See Figure A.1). 3 Figure A.1: Some Possible GSS for the Torus T3 living in E where the grid defines the parallelism 1 Recall that T1 and T2 have been defined in Section 1.1. 110 Appendix A. May a Torus with Null Riemann Curvature Exist on E3? 1 2 Now, T T3 has a global coordinate basis {∂/∂x ,∂/∂x }, and the induced metric on T3 is easily found as g = r2dx1 ⊗ dx1 +(R + r cos x1)2dx2 ⊗ dx2 (A.3) Now, let us introduce a connection ∇ on T3 such that j ∇∂/∂xi ∂/∂x =0. (A.4) With respect to this connection, it is immediately verified that its torsion and curvature tensors are null, but the nonmetricity of the connection is non null. Indeed, 1 1 ∇∂/∂xi g = −2(R + r cos x )sinx . (A.5) So, in this case, we have a particular Riemann-Cartan-Weyl GSS (T3, g, ∇)withA =0 , Θ=0, R =0.
    [Show full text]
  • On the Dynamical Content of Mags
    Home Search Collections Journals About Contact us My IOPscience On the dynamical content of MAGs This content has been downloaded from IOPscience. Please scroll down to see the full text. 2015 J. Phys.: Conf. Ser. 600 012043 (http://iopscience.iop.org/1742-6596/600/1/012043) View the table of contents for this issue, or go to the journal homepage for more Download details: IP Address: 131.169.4.70 This content was downloaded on 07/03/2016 at 23:01 Please note that terms and conditions apply. Spanish Relativity Meeting (ERE 2014): almost 100 years after Einstein’s revolution IOP Publishing Journal of Physics: Conference Series 600 (2015) 012043 doi:10.1088/1742-6596/600/1/012043 On the dynamical content of MAGs Vincenzo Vitagliano CENTRA, Departamento de F´ısica,Instituto Superior T´ecnico,Universidade de Lisboa - UL, Av. Rovisco Pais 1, 1049 Lisboa, Portugal E-mail: [email protected] Abstract. Adopting a procedure borrowed from the effective field theory prescriptions, we study the dynamics of metric-affine theories of increasing order, that in the complete version include invariants built from curvature, nonmetricity and torsion. We show that even including terms obtained from nonmetricity and torsion to the second order density Lagrangian, the connection lacks dynamics and acts as an auxiliary field that can be algebraically eliminated, resulting in some extra interactions between metric and matter fields. Introduction. The intriguing choice to treat alternative theories of gravity by means of the Palatini approach, namely elevating the affine connection to the role of independent variable, contains the seed of some interesting (usually under-explored) generalizations of General Relativity, the metric-affine theories of gravity.
    [Show full text]
  • On the Ontology of Spacetime in a Frame of Reference
    On the Ontology of Spacetime in a Frame of Reference Alexander Poltorak 1 Abstract The spacetime ontology is considered in General Relativity (GR) in view of the choice of a frame of reference (FR). Various approaches to a description of the FR, such as coordinate systems, monads and tetrads are reviewed. It is shown that any of the existing FR definitions require a preexisting background spacetime, which, if defined independently of the FR, renders the spacetime absolute in violation of the principle of relativity, or, if defined within an inertial FR (IFR), as it is usually done, makes the argument circular. Consequently, defining a FR in a preexisting spacetime is unacceptable. We show that a FR defines a differentiable manifold with, generally, non-Euclidean geometry. In a noninertial FR (NIFR) the observer must chose a coordinative definition either admitting existence of a universal – inertial – force or settling for non-Euclidean spacetime. Following Reichenbach, it is preferable to eliminate all universal forces and opt for a non-Euclidean geometry. It is shown that a metric-affine space ( L4,g) is best suited to describe the geometry of spacetime within a FR. Considering a gravitational field in an arbitrary FR, we show within the framework of Einstein’s GR that the gravity is described by nonmetricity of spacetime. This result may shed new light on the nature of the cosmological constant and dark energy. I. Introduction One of the fundamental problems of spacetime ontology is how matter affects the geometry of spacetime and, vice versa, how spacetime affects the behavior of the matter therein.
    [Show full text]
  • Cosmology in Symmetric Teleparallel Gravity and Its Dynamical System
    Eur. Phys. J. C (2019) 79:530 https://doi.org/10.1140/epjc/s10052-019-7038-3 Regular Article - Theoretical Physics Cosmology in symmetric teleparallel gravity and its dynamical system Jianbo Lua, Xin Zhao, Guoying Cheeb Department of Physics, Liaoning Normal University, Dalian 116029, People’s Republic of China Received: 28 February 2019 / Accepted: 10 June 2019 / Published online: 20 June 2019 © The Author(s) 2019 Abstract We explore an extension of the symmetric telepa- symmetric teleparallel connection that is not metric compati- rallel gravity denoted the f (Q) theory, by considering a ble. This classification highlights that curvature is a property function of the nonmetricity invariant Q as the gravitational of the connection and not of the metric tensor or the mani- Lagrangian. Some interesting properties could be found in fold. It becomes a property of the metric only through the use the f (Q) theory by comparing with the f (R) and f (T ) the- of the Levi–Civita connection. GR can be equivalently for- ories. The field equations are derived in the f (Q) theory. mulated in terms of either of these connections. All of them The cosmological application is investigated. In this theory can be used to define Lagrangians of which Euler-Lagrange the accelerating expansion is an intrinsic property of the uni- equations coincide with the Einstein equations for a particu- verse geometry without need of either exotic dark energy or lar choice of contributing terms. extra fields. And the state equation of the geometrical dark In recent years teleparallel theories have gained more energy can cross over the phantom divide line in the f (Q) attention as alternative theories of gravity.
    [Show full text]