Tensorial Spacetime Geometries Carrying Predictive, Interpretable and Quantizable Matter Dynamics

Total Page:16

File Type:pdf, Size:1020Kb

Tensorial Spacetime Geometries Carrying Predictive, Interpretable and Quantizable Matter Dynamics Max-Planck-Institut f¨urGravitationsphysik Dr. Frederic P. Schuller Institut f¨urPhysik und Astronomie Prof. Dr. Martin Wilkens Tensorial spacetime geometries carrying predictive, interpretable and quantizable matter dynamics Dissertation zur Erlangung des akademischen Grades “doctor rerum naturalium” (Dr. rer. nat.) in der Wissenschaftsdisziplin “Mathematische Gravitationsphysik” eingereicht an der Mathematisch-Naturwissenschaftlichen Fakult¨at der Universit¨atPotsdam von Sergio Rivera Hern´andez Potsdam, den 15. Februar 2012 Published online at the Institutional Repository of the University of Potsdam: URL http://opus.kobv.de/ubp/volltexte/2012/6186/ URN urn:nbn:de:kobv:517-opus-61869 http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-61869 A mis padres, con mucho amor y admiraci´on. Contents Acknowledgements 1 Chapter 1. Introduction to spacetime geometries 3 1.1. The conceptual path to general relativity 3 1.2. Observations 8 1.3. New tensorial geometries 11 Chapter 2. Condition I: Hyperbolicity 15 2.1. Initial value problem and hyperbolicity 15 2.2. Hyperbolic polynomials 17 Chapter 3. Condition II: Time-orientability 21 3.1. The short wave approximation and the massless dispersion relation 21 3.2. Solution to the eikonal equation 23 3.3. Massless duality theory: the Gauss map and action for massless particles 25 3.4. Existence and computability of the dual polynomial 28 3.5. Time-orientability 31 Chapter 4. Condition III: Energy-distinguishability 35 4.1. Energy-distinguishing condition 35 4.2. The massive dispersion relation 36 4.3. Massive duality theory: the Legendre map and action for massive particles 38 4.4. Lorentzian Finsler geometry and freely falling observers 41 Chapter 5. General properties of tensorial spacetimes 45 5.1. Observer frames and observer transformations 45 5.2. Temporal-spatial split of modified dispersion relations 47 5.3. `Superluminal' propagation of matter and vacuum Cherenkov process 48 Chapter 6. Concrete tensorial spacetime geometries 53 6.1. Lorentzian geometry 53 6.2. Area metric geometry 57 6.3. Testing modified dispersion relations 70 Chapter 7. Free QED on area metric spacetimes 73 7.1. Hamiltonian formulation and gauge fixing for area metric electrodynamics 73 v vi CONTENTS 7.2. Quantization 77 7.3. Casimir effect in a birefringent linear optical medium 81 Chapter 8. Coupling currents 85 8.1. Covariant propagator 85 8.2. Quantum point charges 87 8.3. General structure of lower order field equations 92 8.4. Examples of second and first order field equations 96 Chapter 9. Towards gravity 101 9.1. Deformation algebra of hypersurfaces. 101 9.2. Dynamical evolution of the geometry. 103 Chapter 10. Conclusions 105 Bibliography 109 Acknowledgements Dear Frederic, this work would not have been possible without your tremendous support in science and in all other aspects, and I have not enough space here to thank you for everything. Thank you for having supervised my doctoral research, I have learnt a lot of physics (but also about other things) from you. In particular, I thank you for conveying the aim to really under- stand and improve things. I really appreciate that you were always open to discuss about any subject and ideas. I thank you for the opportunity to come to this beautiful country, for your trust, for your advices, for your patience, for your help, and, of course, for the coffees. Next, I would like to thank my PhD-colleagues Dennis R¨atzeland Christof Witte. I enjoyed a lot the time we spent working together. Dear Dennis, it was a great time working in our first paper together with Frederic, and also in the quantization of matter fields. Dear Christof, I thank you for the insightful discussions, and it was a pleassure to have worked with you at the \Deutsche Sch¨ulerakademie". I would also like to thank Prof. Dr. Martin Wilkens for acting as my supervisor at the university of Potsdam and Prof. Daniel Sudarsky for his understanding about finishing my PhD in Germany. I thank my wife Vicky and my son Sergito for their love and support over the last years. It is wonderful to share my life with both of you. I also thank my parents, Fernando and Alicia, for their love and support in all circumstances, and my brother Fernando for all experiences we have had together. I would also like to thank Fritz Henke, Frank Michalet, Natividad Batista, Wolfgang and Ingrid Christoph, and my friends Odir Rodriguez and Ivette Cruz for helping me (or my family) in several ways. Finally, I would like to thank the Albert Einstein Institute for its hospitality and support where this doctoral work has been done, and the finacial support of the German Academic Ex- change Service (DAAD). 1 CHAPTER 1 Introduction to spacetime geometries In this doctoral work, we will determine the requirements that a pair (M; G) of a finite- dimensional smooth manifold M and an a priori arbitrary tensor field G must satisfy in order to provide a classical spacetime geometry. This introductory chapter will be devoted to motivate our investigation, to make precise which problem we will solve, and to describe the logical path we will follow. In the first section, we present a review on general relativity based on an idealized historical logic for its construction, which indeed mirrors how we will determine the conditions on (M; G). In the second section, we shortly review the main observations interpreted in the framework of general relativity and the standard model of particle physics. We will argue that these suggest new tensorial geometries to replace Lorentzian metrics as an appropriate mathe- matical structure modelling the physical spacetime structure. Finally, in the third section, we state key conditions that any pair (M; G) must satisfy in order to provide a classical spacetime geometry. The enterprise undertaken in this thesis is to make these conditions mathematically precise, derive rigorous conclusions and apply them to physics. 1.1. The conceptual path to general relativity Historically, Einstein did not directly postulate that spacetime is a pair (M; g) of a finite- dimensional smooth manifold M equipped with a Lorentzian metric g and then made physical constructions on it, as sometimes it is the standard textbook presentation of general relativity. It was rather the study of a matter field, namely the electromagnetic field, that ultimately led Einstein to conclude that the geometry of spacetime could be encoded in a Lorentzian metric [1]. Here it will be precisely this logical path followed by Einstein, namely starting from a study of matter fields, that allows for the identification of the pairs (M; G) that can provide a classical spacetime structure. So let us review, using modern mathematical language, how Einstein constructed general relativity by studying Maxwell electrodynamics. We begin by considering a one-form field A, to be identified with the electromagnetic poten- tial, on a finite-dimensional smooth manifold M. If the manifold M on which the field A lives is equipped with a metric g, a priori not necessarily of Lorentzian signature, we can stipulate the well-known Maxwell action Z 1 4 p ab cd S[A; g] = − d x j det(g)j g g FacF (1.1) 4 bd to provide dynamics for the field A, where F = dA is defined as the field strength, and the ab components of g and Fab are chosen with respect to some coordinate system. Variation of this action with respect to the electromagnetic degrees of freedom A yields a consistent set of partial 3 4 1. INTRODUCTION TO SPACETIME GEOMETRIES differential equations, a priori for any signature of the metric. But if we want to do physics, we want to predict \future" values of the field A, i.e., we want the field equations for the field A to be predictive. More precisely, given initial values of the field A and its first derivatives on an \adequate" hypersurface Σ0 of M, which is all we have access to measure, we want the dynamics arising from the action above to be able to reconstruct in a unique way the values of the field A at a \later" hypersurface Σt. It is a well-known result from the theory of partial differential equations [2, 3] that predictivity in this sense can only be possible if the field equations arising from the considered action are of hyperbolic type. This already amounts to the requirement that the inverse metric g−1 in the action, and therefore the metric g itself, be of Lorentzian signature (and for definiteness, we choose the mainly minus signature (+−· · · −) in the following). Thus the predictivity requirement on the dynamics of the matter field A already restricts a metric manifold (M; g) to be Lorentzian. The adequate hypersurfaces Σ on which initial data can be provided are then recognized as those ∗ whose co-normals q 2 Tx M at each point x of the hypersurface Σ (which are determined up to a non-zero scale) are contained in one of the convex cones C or −C, which are defined as the set of covectors q that are positive with respect to g−1, e.g. the cones defined by −1 gx (q; q) > 0 ; (1.2) see figure 1.1. The physical interpretation of the covectors k on the boundary of the cones C and −C, i.e., those satisfying g−1(k; k) = 0, is obtained by studying the geometric optical limit of the field equations arising from the considered action. This study proceeds by considering wave-like approximate solutions of the form eiS(x)/λ for the field equations obeyed by A, where S is a scalar real function on M, and studying these for arbitrary small wavelength λ. These approximate solutions then correspond to high-frequency propagating waves whenever the wave- length is negligible in comparison to other relevant length scales.
Recommended publications
  • Algebraic Geometry Michael Stoll
    Introductory Geometry Course No. 100 351 Fall 2005 Second Part: Algebraic Geometry Michael Stoll Contents 1. What Is Algebraic Geometry? 2 2. Affine Spaces and Algebraic Sets 3 3. Projective Spaces and Algebraic Sets 6 4. Projective Closure and Affine Patches 9 5. Morphisms and Rational Maps 11 6. Curves — Local Properties 14 7. B´ezout’sTheorem 18 2 1. What Is Algebraic Geometry? Linear Algebra can be seen (in parts at least) as the study of systems of linear equations. In geometric terms, this can be interpreted as the study of linear (or affine) subspaces of Cn (say). Algebraic Geometry generalizes this in a natural way be looking at systems of polynomial equations. Their geometric realizations (their solution sets in Cn, say) are called algebraic varieties. Many questions one can study in various parts of mathematics lead in a natural way to (systems of) polynomial equations, to which the methods of Algebraic Geometry can be applied. Algebraic Geometry provides a translation between algebra (solutions of equations) and geometry (points on algebraic varieties). The methods are mostly algebraic, but the geometry provides the intuition. Compared to Differential Geometry, in Algebraic Geometry we consider a rather restricted class of “manifolds” — those given by polynomial equations (we can allow “singularities”, however). For example, y = cos x defines a perfectly nice differentiable curve in the plane, but not an algebraic curve. In return, we can get stronger results, for example a criterion for the existence of solutions (in the complex numbers), or statements on the number of solutions (for example when intersecting two curves), or classification results.
    [Show full text]
  • Topics in Complex Analytic Geometry
    version: February 24, 2012 (revised and corrected) Topics in Complex Analytic Geometry by Janusz Adamus Lecture Notes PART II Department of Mathematics The University of Western Ontario c Copyright by Janusz Adamus (2007-2012) 2 Janusz Adamus Contents 1 Analytic tensor product and fibre product of analytic spaces 5 2 Rank and fibre dimension of analytic mappings 8 3 Vertical components and effective openness criterion 17 4 Flatness in complex analytic geometry 24 5 Auslander-type effective flatness criterion 31 This document was typeset using AMS-LATEX. Topics in Complex Analytic Geometry - Math 9607/9608 3 References [I] J. Adamus, Complex analytic geometry, Lecture notes Part I (2008). [A1] J. Adamus, Natural bound in Kwieci´nski'scriterion for flatness, Proc. Amer. Math. Soc. 130, No.11 (2002), 3165{3170. [A2] J. Adamus, Vertical components in fibre powers of analytic spaces, J. Algebra 272 (2004), no. 1, 394{403. [A3] J. Adamus, Vertical components and flatness of Nash mappings, J. Pure Appl. Algebra 193 (2004), 1{9. [A4] J. Adamus, Flatness testing and torsion freeness of analytic tensor powers, J. Algebra 289 (2005), no. 1, 148{160. [ABM1] J. Adamus, E. Bierstone, P. D. Milman, Uniform linear bound in Chevalley's lemma, Canad. J. Math. 60 (2008), no.4, 721{733. [ABM2] J. Adamus, E. Bierstone, P. D. Milman, Geometric Auslander criterion for flatness, to appear in Amer. J. Math. [ABM3] J. Adamus, E. Bierstone, P. D. Milman, Geometric Auslander criterion for openness of an algebraic morphism, preprint (arXiv:1006.1872v1). [Au] M. Auslander, Modules over unramified regular local rings, Illinois J.
    [Show full text]
  • Phylogenetic Algebraic Geometry
    PHYLOGENETIC ALGEBRAIC GEOMETRY NICHOLAS ERIKSSON, KRISTIAN RANESTAD, BERND STURMFELS, AND SETH SULLIVANT Abstract. Phylogenetic algebraic geometry is concerned with certain complex projec- tive algebraic varieties derived from finite trees. Real positive points on these varieties represent probabilistic models of evolution. For small trees, we recover classical geometric objects, such as toric and determinantal varieties and their secant varieties, but larger trees lead to new and largely unexplored territory. This paper gives a self-contained introduction to this subject and offers numerous open problems for algebraic geometers. 1. Introduction Our title is meant as a reference to the existing branch of mathematical biology which is known as phylogenetic combinatorics. By “phylogenetic algebraic geometry” we mean the study of algebraic varieties which represent statistical models of evolution. For general background reading on phylogenetics we recommend the books by Felsenstein [11] and Semple-Steel [21]. They provide an excellent introduction to evolutionary trees, from the perspectives of biology, computer science, statistics and mathematics. They also offer numerous references to relevant papers, in addition to the more recent ones listed below. Phylogenetic algebraic geometry furnishes a rich source of interesting varieties, includ- ing familiar ones such as toric varieties, secant varieties and determinantal varieties. But these are very special cases, and one quickly encounters a cornucopia of new varieties. The objective of this paper is to give an introduction to this subject area, aimed at students and researchers in algebraic geometry, and to suggest some concrete research problems. The basic object in a phylogenetic model is a tree T which is rooted and has n labeled leaves.
    [Show full text]
  • Chapter 2 Affine Algebraic Geometry
    Chapter 2 Affine Algebraic Geometry 2.1 The Algebraic-Geometric Dictionary The correspondence between algebra and geometry is closest in affine algebraic geom- etry, where the basic objects are solutions to systems of polynomial equations. For many applications, it suffices to work over the real R, or the complex numbers C. Since important applications such as coding theory or symbolic computation require finite fields, Fq , or the rational numbers, Q, we shall develop algebraic geometry over an arbitrary field, F, and keep in mind the important cases of R and C. For algebraically closed fields, there is an exact and easily motivated correspondence be- tween algebraic and geometric concepts. When the field is not algebraically closed, this correspondence weakens considerably. When that occurs, we will use the case of algebraically closed fields as our guide and base our definitions on algebra. Similarly, the strongest and most elegant results in algebraic geometry hold only for algebraically closed fields. We will invoke the hypothesis that F is algebraically closed to obtain these results, and then discuss what holds for arbitrary fields, par- ticularly the real numbers. Since many important varieties have structures which are independent of the field of definition, we feel this approach is justified—and it keeps our presentation elementary and motivated. Lastly, for the most part it will suffice to let F be R or C; not only are these the most important cases, but they are also the sources of our geometric intuitions. n Let A denote affine n-space over F. This is the set of all n-tuples (t1,...,tn) of elements of F.
    [Show full text]
  • 18.782 Arithmetic Geometry Lecture Note 1
    Introduction to Arithmetic Geometry 18.782 Andrew V. Sutherland September 5, 2013 1 What is arithmetic geometry? Arithmetic geometry applies the techniques of algebraic geometry to problems in number theory (a.k.a. arithmetic). Algebraic geometry studies systems of polynomial equations (varieties): f1(x1; : : : ; xn) = 0 . fm(x1; : : : ; xn) = 0; typically over algebraically closed fields of characteristic zero (like C). In arithmetic geometry we usually work over non-algebraically closed fields (like Q), and often in fields of non-zero characteristic (like Fp), and we may even restrict ourselves to rings that are not a field (like Z). 2 Diophantine equations Example (Pythagorean triples { easy) The equation x2 + y2 = 1 has infinitely many rational solutions. Each corresponds to an integer solution to x2 + y2 = z2. Example (Fermat's last theorem { hard) xn + yn = zn has no rational solutions with xyz 6= 0 for integer n > 2. Example (Congruent number problem { unsolved) A congruent number n is the integer area of a right triangle with rational sides. For example, 5 is the area of a (3=2; 20=3; 41=6) triangle. This occurs iff y2 = x3 − n2x has infinitely many rational solutions. Determining when this happens is an open problem (solved if BSD holds). 3 Hilbert's 10th problem Is there a process according to which it can be determined in a finite number of operations whether a given Diophantine equation has any integer solutions? The answer is no; this problem is formally undecidable (proved in 1970 by Matiyasevich, building on the work of Davis, Putnam, and Robinson). It is unknown whether the problem of determining the existence of rational solutions is undecidable or not (it is conjectured to be so).
    [Show full text]
  • Spacetime Structuralism
    Philosophy and Foundations of Physics 37 The Ontology of Spacetime D. Dieks (Editor) r 2006 Elsevier B.V. All rights reserved DOI 10.1016/S1871-1774(06)01003-5 Chapter 3 Spacetime Structuralism Jonathan Bain Humanities and Social Sciences, Polytechnic University, Brooklyn, NY 11201, USA Abstract In this essay, I consider the ontological status of spacetime from the points of view of the standard tensor formalism and three alternatives: twistor theory, Einstein algebras, and geometric algebra. I briefly review how classical field theories can be formulated in each of these formalisms, and indicate how this suggests a structural realist interpre- tation of spacetime. 1. Introduction This essay is concerned with the following question: If it is possible to do classical field theory without a 4-dimensional differentiable manifold, what does this suggest about the ontological status of spacetime from the point of view of a semantic realist? In Section 2, I indicate why a semantic realist would want to do classical field theory without a manifold. In Sections 3–5, I indicate the extent to which such a feat is possible. Finally, in Section 6, I indicate the type of spacetime realism this feat suggests. 2. Manifolds and manifold substantivalism In classical field theories presented in the standard tensor formalism, spacetime is represented by a differentiable manifold M and physical fields are represented by tensor fields that quantify over the points of M. To some authors, this has 38 J. Bain suggested an ontological commitment to spacetime points (e.g., Field, 1989; Earman, 1989). This inclination might be seen as being motivated by a general semantic realist desire to take successful theories at their face value, a desire for a literal interpretation of the claims such theories make (Earman, 1993; Horwich, 1982).
    [Show full text]
  • IV.5 Arithmetic Geometry Jordan S
    i 372 IV. Branches of Mathematics where the aj,i1,...,in are indeterminates. If we write with many nice pictures and reproductions. A Scrap- g1f1 + ··· + gmfm as a polynomial in the variables book of Complex Curve Theory (American Mathemat- x1,...,xn, then all the coefficients must vanish, save ical Society, Providence, RI, 2003), by C. H. Clemens, the constant term which must equal 1. Thus we get and Complex Algebraic Curves (Cambridge University a system of linear equations in the indeterminates Press, Cambridge, 1992), by F. Kirwan, also start at an easily accessible level, but then delve more quickly into aj,i1,...,in . The solvability of systems of linear equations is well-known (with good computer implementations). advanced subjects. Thus we can decide if there is a solution with deg gj The best introduction to the techniques of algebraic 100. Of course it is possible that 100 was too small geometry is Undergraduate Algebraic Geometry (Cam- a guess, and we may have to repeat the process with bridge University Press, Cambridge, 1988), by M. Reid. larger and larger degree bounds. Will this ever end? For those wishing for a general overview, An Invitation The answer is given by the following result, which was to Algebraic Geometry (Springer, New York, 2000), by proved only recently. K. E. Smith, L. Kahanpää, P. Kekäläinen, and W. Traves, is a good choice, while Algebraic Geometry (Springer, New Effective Nullstellensatz. Let f1,...,fm be polyno- York, 1995), by J. Harris, and Basic Algebraic Geometry, mials of degree less than or equal to d in n variables, volumes I and II (Springer, New York, 1994), by I.
    [Show full text]
  • Arithmetic Dynamics, Arithmetic Geometry, and Number Theory Joseph H
    Arithmetic Dynamics, Arithmetic Geometry, and Number Theory Joseph H. Silverman Brown University MAGNTS (Midwest Arithmetic Geometry and Number Theory Series) October 12{13, 2019 0 Arithmetic Dynamics and Arithmetic Geometry 1 What is Arithmetic Dynamics? Arithmetic Geometry: Study solutions to polyno- mial equations (points on algebraic varieties) over non- algebraically closed fields. (Discrete) Dynamical Systems: Study orbits of points under iteration of a function. Arithmetic Dynamics: Study number theoretic prop- erties of orbits of points on algebraic varieties. A lot of arithmetic dynamics comes by analogy from arithmetic geometry. Sometimes the analogy is quite di- rect, sometimes less so, and there are parts of arithmetic geometry that still lack dynamical analogues. Today's talk will be a survey of what arithmetic dynamics is all about, with details on its connections to the arithmetic geometry that we all know and love. Then in tomorrow's talk I'll delve more deeply into some specific topics. Arithmetic Dynamics and Arithmetic Geometry 2 In Arithmetic Geometry We Study . Elliptic curves / higher dim'l abelian varieties Torsion points Torsion points defined over a fixed K. Fields generated by torsion points. Image of Galois G(K=K¯ ) ! Aut(Ators). Torsion points on subvarieties (dim A ≥ 2). Mordell{Weil groups Rank of K-rational points . for fixed A and varying K; for fixed K and varying A. Intersection with subvarieties (dim A ≥ 2). Moduli spaces of elliptic curve and abelian varieties Geometry of moduli spaces, e.g., X0(N) and Ag. Distribution of \special" points (CM moduli). Modular forms, L-series, Hecke operators, . Arithmetic Dynamics and Arithmetic Geometry 3 In Discrete Dynamics We Study .
    [Show full text]
  • Lectures on Analytic Geometry Peter Scholze (All Results Joint with Dustin
    Lectures on Analytic Geometry Peter Scholze (all results joint with Dustin Clausen) Contents Analytic Geometry 5 Preface 5 1. Lecture I: Introduction 6 2. Lecture II: Solid modules 11 3. Lecture III: Condensed R-vector spaces 16 4. Lecture IV: M-complete condensed R-vector spaces 20 Appendix to Lecture IV: Quasiseparated condensed sets 26 + 5. Lecture V: Entropy and a real BdR 28 6. Lecture VI: Statement of main result 33 Appendix to Lecture VI: Recollections on analytic rings 39 7. Lecture VII: Z((T ))>r is a principal ideal domain 42 8. Lecture VIII: Reduction to \Banach spaces" 47 Appendix to Lecture VIII: Completions of normed abelian groups 54 Appendix to Lecture VIII: Derived inverse limits 56 9. Lecture IX: End of proof 57 Appendix to Lecture IX: Some normed homological algebra 65 10. Lecture X: Some computations with liquid modules 69 11. Lecture XI: Towards localization 73 12. Lecture XII: Localizations 79 Appendix to Lecture XII: Topological invariance of analytic ring structures 86 Appendix to Lecture XII: Frobenius 89 Appendix to Lecture XII: Normalizations of analytic animated rings 93 13. Lecture XIII: Analytic spaces 95 14. Lecture XIV: Varia 103 Bibliography 109 3 Analytic Geometry Preface These are lectures notes for a course on analytic geometry taught in the winter term 2019/20 at the University of Bonn. The material presented is part of joint work with Dustin Clausen. The goal of this course is to use the formalism of analytic rings as defined in the course on condensed mathematics to define a category of analytic spaces that contains (for example) adic spaces and complex-analytic spaces, and to adapt the basics of algebraic geometry to this context; in particular, the theory of quasicoherent sheaves.
    [Show full text]
  • An Introduction to Homological Mirror Symmetry and the Case of Elliptic Curves
    AN INTRODUCTION TO HOMOLOGICAL MIRROR SYMMETRY AND THE CASE OF ELLIPTIC CURVES ANDREW PORT Abstract. Here we carefully construct an equivalence between the derived category of coherent sheaves on an elliptic curve and a version of the Fukaya category on its mirror. This is the most accessible case of homological mirror symmetry. We also provide introductory background on the general Calabi-Yau case of The Homological Mirror Symmetry Conjecture. Contents 0. Introduction 2 1. Complex, Symplectic and K¨ahlermanifolds 4 1.1. Complex manifolds 4 1.2. Almost Complex Structures 5 1.3. Symplectic Geometry 5 1.4. Lagrangian submanifolds and Hamiltonian flows 7 1.5. K¨ahlerGeometry 8 1.6. Calabi-Yau Manifolds 8 2. Complex and Holomorphic Vector Bundles 9 2.1. Complex Vector Bundles 9 2.2. Connections on Vector Bundles 10 2.3. Holomorphic Vector Bundles 11 2.4. Sections of a holomorphic vector bundles 12 3. A Review of Elliptic Curves 14 3.1. Complex structures on Elliptic curves 14 3.2. The Calabi-Yau Structure of an Elliptic curve 14 4. Holomorphic Line Bundles on Elliptic Curves 15 4.1. Theta Functions 15 4.2. The Category of Holomorphic Line Bundles on Elliptic curves 17 5. The A-side 18 5.1. B-fields and the K¨ahlerModuli Space 18 arXiv:1501.00730v1 [math.SG] 4 Jan 2015 5.2. The Fukaya Category 19 5.3. The Objects 20 5.4. The Morphisms 20 5.5. The A1-structure 21 6. The Simplest Example 23 7. The B-side 27 7.1. The Derived Category of Coherent Sheaves 27 7.2.
    [Show full text]
  • Diophantine-Geometry-Course.Pdf
    DIOPHANTINE GEOMETRY { TAUGHT BY JOE SILVERMAN NOTES BY SHAMIL ASGARLI 1. Diophantine Equations Objective. Solve polynomial equations using integers (or rationals). Example. Linear equation: Solve ax + by = c where a; b; c 2 Z. It is a classical fact from elementary number theory that this equation has a solution (for x and y) if and only if gcd(a; b) j c. Example. Quadratic equation: x2 + y2 = z2. We are interested in non-zero solutions (x; y; z) 2 Z, i.e. (x; y; z) 6= (0; 0; 0). Since the equation is homogeneous, it is enough to understand the solutions of X2 + Y 2 = 1 where X; Y 2 Q (points on the unit circle). Anyways, the complete solution is known for this problem. WLOG gcd(x; y; z) = 1, x is odd and y is even. Then the solutions are given by x = s2 − t2, y = 2st, and z = s2 + t2. s2 − t2 Analogously, the solutions (X; Y ) 2 2 of X2 + Y 2 = 1 are parametrized by: X = Q s2 + t2 2st and Y = . s2 + t2 Example. Consider the equation y2 = x3 − 2. It turns out that (3; ±5) are the only solutions in Z2, while there are infinitely many solutions (x; y) 2 Q. Goal. Given f1; f2; :::; fk 2 Z[X1; :::; Xn]. For R = Z; Q, or any other ring. Let n V (R) = f(x1; x2; :::; xn) 2 R : fi(x1; :::; xn) = 0 for all ig Describe V (R). Two questions naturally arise. 1) Is V (R) = ;? This is undecidable for R = Z. 2) Is V (R) finite? 2 variables, 1 equation.
    [Show full text]
  • Notes on Basic Algebraic Geometry
    Notes on basic algebraic geometry June 16, 2008 These are my notes for an introductory course in algebraic geometry. I have trodden lightly through the theory and concentrated more on examples. Some examples are handled on the computer using Macaulay2, although I use this as only a tool and won’t really dwell on the computational issues. Of course, any serious student of the subject should go on to learn about schemes and cohomology, and (at least from my point of view) some of the analytic theory as well. Hartshorne [Ht] has become the canonical introduction to the first topic, and Griffiths-Harris [GH] the second. 1 Contents 1 Affine Geometry 3 1.1 Algebraic sets ............................. 3 1.2 Weak Nullstellensatz ......................... 5 1.3 Zariski topology ........................... 7 1.4 The Cayley-Hamilton theorem ................... 9 1.5 Affine Varieties ............................ 10 1.6 Hilbert’s Nullstellensatz ....................... 11 1.7 Nilpotent matrices .......................... 12 2 Projective Geometry 15 2.1 Projective space ........................... 15 2.2 Projective varieties .......................... 16 2.3 Projective closure ........................... 17 2.4 Miscellaneous examples ....................... 18 2.5 Grassmanians ............................. 19 2.6 Elimination theory .......................... 22 2.7 Simultaneous eigenvectors ...................... 23 3 The category of varieties 26 3.1 Rational functions .......................... 26 3.2 Quasi-projective varieties ...................... 27 3.3
    [Show full text]