Diophantine Geometry in Space And
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Minkowski's Geometry of Numbers
Geometry of numbers MAT4250 — Høst 2013 Minkowski’s geometry of numbers Preliminary version. Version +2✏ — 31. oktober 2013 klokken 12:04 1 Lattices Let V be a real vector space of dimension n.Byalattice L in V we mean a discrete, additive subgroup. We say that L is a full lattice if it spans V .Ofcourse,anylattice is a full lattice in the subspace it spans. The lattice L is discrete in the induced topology, meaning that for any point x L 2 there is an open subset U of V whose intersection with L is just x.Forthesubgroup L to be discrete it is sufficient that this holds for the origin, i.e., that there is an open neigbourhood U about 0 with U L = 0 .Indeed,ifx L,thenthetranslate \ { } 2 U 0 = U + x is open and intersects L in the set x . { } Aoftenusefulpropertyofalatticeisthatithasonlyfinitelymanypointsinany bounded subset of V .Toseethis,letS V be a bounded set and assume that L S is ✓ \ infinite. One may then pick a sequence xn of different elements from L S.SinceS { } \ is bounded, its closure is compact and xn has a subsequence that converges, say to { } x. Then x is an accumulation point in L;everyneigbourhoodcontainselementsfrom L distinct from x. The lattice associated to a basis If = v1,...,vn is any basis for V ,onemayconsiderthesubgroupL = Zvi of B { } B i V consisting of all linear combinations of the vi’s with integral coefficients. Clearly L P B is a discrete subspace of V ;IfonetakesU to be an open ball centered at the origin and having radius less than mini vi ,thenU L = 0 .HenceL is a full lattice in k k \ { } B V . -
The Diophantine Equation X 2 + C = Y N : a Brief Overview
Revista Colombiana de Matem¶aticas Volumen 40 (2006), p¶aginas31{37 The Diophantine equation x 2 + c = y n : a brief overview Fadwa S. Abu Muriefah Girls College Of Education, Saudi Arabia Yann Bugeaud Universit¶eLouis Pasteur, France Abstract. We give a survey on recent results on the Diophantine equation x2 + c = yn. Key words and phrases. Diophantine equations, Baker's method. 2000 Mathematics Subject Classi¯cation. Primary: 11D61. Resumen. Nosotros hacemos una revisi¶onacerca de resultados recientes sobre la ecuaci¶onDiof¶antica x2 + c = yn. 1. Who was Diophantus? The expression `Diophantine equation' comes from Diophantus of Alexandria (about A.D. 250), one of the greatest mathematicians of the Greek civilization. He was the ¯rst writer who initiated a systematic study of the solutions of equations in integers. He wrote three works, the most important of them being `Arithmetic', which is related to the theory of numbers as distinct from computation, and covers much that is now included in Algebra. Diophantus introduced a better algebraic symbolism than had been known before his time. Also in this book we ¯nd the ¯rst systematic use of mathematical notation, although the signs employed are of the nature of abbreviations for words rather than algebraic symbols in contemporary mathematics. Special symbols are introduced to present frequently occurring concepts such as the unknown up 31 32 F. S. ABU M. & Y. BUGEAUD to its sixth power. He stands out in the history of science as one of the great unexplained geniuses. A Diophantine equation or indeterminate equation is one which is to be solved in integral values of the unknowns. -
Arithmetic Sequences, Diophantine Equations and the Number of the Beast Bryan Dawson Union University
Arithmetic Sequences, Diophantine Equations and the Number of the Beast Bryan Dawson Union University Here is wisdom. Let him who has understanding calculate the number of the beast, for it is the number of a man: His number is 666. -Revelation 13:18 (NKJV) "Let him who has understanding calculate ... ;" can anything be more enticing to a mathe matician? The immediate question, though, is how do we calculate-and there are no instructions. But more to the point, just who might 666 be? We can find anything on the internet, so certainly someone tells us. A quick search reveals the answer: according to the "Gates of Hell" website (Natalie, 1998), 666 refers to ... Bill Gates ill! In the calculation offered by the website, each letter in the name is replaced by its ASCII character code: B I L L G A T E S I I I 66 73 76 76 71 65 84 69 83 1 1 1 = 666 (Notice, however, that an exception is made for the suffix III, where the value of the suffix is given as 3.) The big question is this: how legitimate is the calculation? To answer this question, we need to know several things: • Can this same type of calculation be performed on other names? • What mathematics is behind such calculations? • Have other types of calculations been used to propose a candidate for 666? • What type of calculation did John have in mind? Calculations To answer the first two questions, we need to understand the ASCII character code. The ASCII character code replaces characters with numbers in order to have a numeric way of storing all characters. -
Chapter 2 Geometry of Numbers
Chapter 2 Geometry of numbers Literature: W.M. Schmidt, Diophantine approximation, Lecture Notes in Mathematics 785, Springer Verlag 1980, Chap.II, xx1,2, Chap. IV, x1 J.W.S. Cassels, An Introduction to the Geometry of Numbers, Springer Verlag 1997, Classics in Mathematics series, reprint of the 1971 edition C.L. Siegel, Lectures on the Geometry of Numbers, Springer Verlag 1989 2.1 Introduction Geometry of numbers is concerned with the study of lattice points in certain bodies n in R , where n > 2. We discuss Minkowski's theorems on lattice points in central symmetric convex bodies. In this introduction we give the necessary definitions. Lattices. A (full) lattice in Rn is an additive group L = fz1v1 + ··· + znvn : z1; : : : ; zn 2 Zg n where fv1;:::; vng is a basis of R , i.e., fv1;:::; vng is linearly independent. We call fv1;:::; vng a basis of L. The determinant of L is defined by d(L) := j det(v1;:::; vn)j; that is, the absolute value of the determinant of the matrix with columns v1;:::; vn. 7 We show that the determinant of a lattice does not depend on the choice of the basis. Recall that GL(n; Z) is the multiplicative group of n×n-matrices with entries in Z and determinant ±1. Lemma 2.1. Let L be a lattice, and fv1;:::; vng, fw1;:::; wng two bases of L. Then there is a matrix U = (uij) 2 GL(n; Z) such that n X (2.1) wi = uijvj for i = 1; : : : ; n: j=1 Consequently, j det(v1;:::; vn)j = j det(w1;:::; wn)j. -
Introductory Number Theory Course No
Introductory Number Theory Course No. 100 331 Spring 2006 Michael Stoll Contents 1. Very Basic Remarks 2 2. Divisibility 2 3. The Euclidean Algorithm 2 4. Prime Numbers and Unique Factorization 4 5. Congruences 5 6. Coprime Integers and Multiplicative Inverses 6 7. The Chinese Remainder Theorem 9 8. Fermat’s and Euler’s Theorems 10 × n × 9. Structure of Fp and (Z/p Z) 12 10. The RSA Cryptosystem 13 11. Discrete Logarithms 15 12. Quadratic Residues 17 13. Quadratic Reciprocity 18 14. Another Proof of Quadratic Reciprocity 23 15. Sums of Squares 24 16. Geometry of Numbers 27 17. Ternary Quadratic Forms 30 18. Legendre’s Theorem 32 19. p-adic Numbers 35 20. The Hilbert Norm Residue Symbol 40 21. Pell’s Equation and Continued Fractions 43 22. Elliptic Curves 50 23. Primes in arithmetic progressions 66 24. The Prime Number Theorem 75 References 80 2 1. Very Basic Remarks The following properties of the integers Z are fundamental. (1) Z is an integral domain (i.e., a commutative ring such that ab = 0 implies a = 0 or b = 0). (2) Z≥0 is well-ordered: every nonempty set of nonnegative integers has a smallest element. (3) Z satisfies the Archimedean Principle: if n > 0, then for every m ∈ Z, there is k ∈ Z such that kn > m. 2. Divisibility 2.1. Definition. Let a, b be integers. We say that “a divides b”, written a | b , if there is an integer c such that b = ac. In this case, we also say that “a is a divisor of b” or that “b is a multiple of a”. -
Exercises for Geometry of Numbers Week 8: 01.05.2020
EXERCISES FOR GEOMETRY OF NUMBERS WEEK 8: 01.05.2020 Exercise 1. 1. Consider all the intervals of the form [a2t; (a + 1)2t] with a; t non- ∗ negative integers. For s 2 N , let Ls be the collection of such intervals with t ≤ s − 1 s s contained in [0; 2 ]. Show that for any k 2 N with k ≤ 2 , the interval [0; k] can be covered by at most s elements of Ls. 2. Let F : [0; 1] × (0; 1) be a bounded measurable function and suppose that there exists c > 0 such that for every interval (a; b) ⊂ (0; 1), we have Z 1 Z b 2 F (x; t)dt dx ≤ c(b − a): 0 a Show that 2 X Z 1 Z F (x; t)dt dx ≤ cs2s: 0 I I2Ls ∗ 3. Fix > 0. Show that for every s 2 N , there exists a measurable set As ⊂ [0; 1] such −1−" 1 s that jAsj = O(s ) and for every y2 = As and for every k 2 N with k ≤ 2 , we have Z k s 3 + j F (t; y)dtj ≤ 2 2 s 2 : 0 4. Deduce from 3. 2 that for a.e. y 2 [0; 1], we have Z T 1 − 1 3 j F (y; t)dtj = O(T 2 log(T ) 2 ) T 0 Although the arithmetic functions are not the main focus of the course, the next two exercises touch upon those and aim at proving the arithmetic estimate used in Schmidt's a.s. counting theorem. -
Artin L-Functions and Arithmetic Equivalence (Evan Dummit, September 2013)
Artin L-Functions and Arithmetic Equivalence (Evan Dummit, September 2013) 1 Intro • This is a prep talk for Guillermo Mantilla-Soler's talk. • There are approximately 3 parts of this talk: ◦ First, I will talk about Artin L-functions (with some examples you should know) and in particular try to explain very vaguely what local root numbers are. This portion is adapted from Neukirch and Rohrlich. ◦ Second, I will do a bit of geometry of numbers and talk about quadratic forms and lattices. ◦ Finally, I will talk about arithmetic equivalence and try to give some of the broader context for Guillermo's results (adapted mostly from his preprints). • Just to give the avor of things, here is the theorem Guillermo will probably be talking about: ◦ Theorem (Mantilla-Soler): Let K; L be two non-totally-real, tamely ramied number elds of the same discriminant and signature. Then the integral trace forms of K and L are isometric if and only if for all odd primes p dividing disc(K) the p-local root numbers of ρK and ρL coincide. 2 Artin L-Functions and Root Numbers • Let L=K be a Galois extension of number elds with Galois group G, and ρ be a complex representation of G, which we think of as ρ : G ! GL(V ). • Let p be a prime of K, Pjp a prime of L above p, with kL = OL=P and kK = OK =p the corresponding residue elds, and also let GP and IP be the decomposition and inertia groups of P above p. ∼ • By standard things, the group GP=IP = G(kL=kK ) is generated by the Frobenius element FrobP (which in the group on the right is just the standard q-power Frobenius where q = Nm(p)), so we can think of it as acting on the invariant space V IP . -
Survey of Modern Mathematical Topics Inspired by History of Mathematics
Survey of Modern Mathematical Topics inspired by History of Mathematics Paul L. Bailey Department of Mathematics, Southern Arkansas University E-mail address: [email protected] Date: January 21, 2009 i Contents Preface vii Chapter I. Bases 1 1. Introduction 1 2. Integer Expansion Algorithm 2 3. Radix Expansion Algorithm 3 4. Rational Expansion Property 4 5. Regular Numbers 5 6. Problems 6 Chapter II. Constructibility 7 1. Construction with Straight-Edge and Compass 7 2. Construction of Points in a Plane 7 3. Standard Constructions 8 4. Transference of Distance 9 5. The Three Greek Problems 9 6. Construction of Squares 9 7. Construction of Angles 10 8. Construction of Points in Space 10 9. Construction of Real Numbers 11 10. Hippocrates Quadrature of the Lune 14 11. Construction of Regular Polygons 16 12. Problems 18 Chapter III. The Golden Section 19 1. The Golden Section 19 2. Recreational Appearances of the Golden Ratio 20 3. Construction of the Golden Section 21 4. The Golden Rectangle 21 5. The Golden Triangle 22 6. Construction of a Regular Pentagon 23 7. The Golden Pentagram 24 8. Incommensurability 25 9. Regular Solids 26 10. Construction of the Regular Solids 27 11. Problems 29 Chapter IV. The Euclidean Algorithm 31 1. Induction and the Well-Ordering Principle 31 2. Division Algorithm 32 iii iv CONTENTS 3. Euclidean Algorithm 33 4. Fundamental Theorem of Arithmetic 35 5. Infinitude of Primes 36 6. Problems 36 Chapter V. Archimedes on Circles and Spheres 37 1. Precursors of Archimedes 37 2. Results from Euclid 38 3. Measurement of a Circle 39 4. -
The Circle Method
The Circle Method Steven J. Miller and Ramin Takloo-Bighash July 14, 2004 Contents 1 Introduction to the Circle Method 3 1.1 Origins . 3 1.1.1 Partitions . 4 1.1.2 Waring’s Problem . 6 1.1.3 Goldbach’s conjecture . 9 1.2 The Circle Method . 9 1.2.1 Problems . 10 1.2.2 Setup . 11 1.2.3 Convergence Issues . 12 1.2.4 Major and Minor arcs . 13 1.2.5 Historical Remark . 14 1.2.6 Needed Number Theory Results . 15 1.3 Goldbach’s conjecture revisited . 16 1.3.1 Setup . 16 2 1.3.2 Average Value of |FN (x)| ............................. 17 1.3.3 Large Values of FN (x) ............................... 19 1.3.4 Definition of the Major and Minor Arcs . 20 1.3.5 The Major Arcs and the Singular Series . 22 1.3.6 Contribution from the Minor Arcs . 25 1.3.7 Why Goldbach’s Conjecture is Hard . 26 2 Circle Method: Heuristics for Germain Primes 29 2.1 Germain Primes . 29 2.2 Preliminaries . 31 2.2.1 Germain Integral . 32 2.2.2 The Major and Minor Arcs . 33 2.3 FN (x) and u(x) ....................................... 34 2.4 Approximating FN (x) on the Major arcs . 35 1 2.4.1 Boundary Term . 38 2.4.2 Integral Term . 40 2.5 Integrals over the Major Arcs . 42 2.5.1 Integrals of u(x) .................................. 42 2.5.2 Integrals of FN (x) ................................. 45 2.6 Major Arcs and the Singular Series . 46 2.6.1 Properties of Arithmetic Functions . -
Report on Diophantine Approximations Bulletin De La S
BULLETIN DE LA S. M. F. SERGE LANG Report on Diophantine approximations Bulletin de la S. M. F., tome 93 (1965), p. 177-192 <http://www.numdam.org/item?id=BSMF_1965__93__177_0> © Bulletin de la S. M. F., 1965, tous droits réservés. L’accès aux archives de la revue « Bulletin de la S. M. F. » (http: //smf.emath.fr/Publications/Bulletin/Presentation.html) implique l’accord avec les conditions générales d’utilisation (http://www.numdam.org/ conditions). Toute utilisation commerciale ou impression systématique est constitutive d’une infraction pénale. Toute copie ou impression de ce fichier doit contenir la présente mention de copyright. Article numérisé dans le cadre du programme Numérisation de documents anciens mathématiques http://www.numdam.org/ Bull. Soc. math. France^ 93, ig65, p. 177 a 192. REPORT ON DIOPHANTINE APPROXIMATIONS (*) ; SERGE LANG. The theory of transcendental numbers and diophantine approxi- mations has only few results, most of which now appear isolated. It is difficult, at the present stage of development, to extract from the lite- rature more than what seems a random collection of statements, and this causes a vicious circle : On the one hand, technical difficulties make it difficult to enter the subject, since some definite ultimate goal seems to be lacking. On the other hand, because there are few results, there is not too much evidence to make sweeping conjectures, which would enhance the attractiveness of the subject. With these limitations in mind, I have nevertheless attempted to break the vicious circle by imagining what would be an optimal situa- tion, and perhaps recklessly to give a coherent account of what the theory might turn out to be. -
Solving Elliptic Diophantine Equations: the General Cubic Case
ACTA ARITHMETICA LXXXVII.4 (1999) Solving elliptic diophantine equations: the general cubic case by Roelof J. Stroeker (Rotterdam) and Benjamin M. M. de Weger (Krimpen aan den IJssel) Introduction. In recent years the explicit computation of integer points on special models of elliptic curves received quite a bit of attention, and many papers were published on the subject (see for instance [ST94], [GPZ94], [Sm94], [St95], [Tz96], [BST97], [SdW97], [ST97]). The overall picture before 1994 was that of a field with many individual results but lacking a comprehensive approach to effectively settling the el- liptic equation problem in some generality. But after S. David obtained an explicit lower bound for linear forms in elliptic logarithms (cf. [D95]), the elliptic logarithm method, independently developed in [ST94] and [GPZ94] and based upon David’s result, provided a more generally applicable ap- proach for solving elliptic equations. First Weierstraß equations were tack- led (see [ST94], [Sm94], [St95], [BST97]), then in [Tz96] Tzanakis considered quartic models and in [SdW97] the authors gave an example of an unusual cubic non-Weierstraß model. In the present paper we shall treat the general case of a cubic diophantine equation in two variables, representing an elliptic curve over Q. We are thus interested in the diophantine equation (1) f(u, v) = 0 in rational integers u, v, where f Q[x,y] is of degree 3. Moreover, we require (1) to represent an elliptic curve∈ E, that is, a curve of genus 1 with at least one rational point (u0, v0). 1991 Mathematics Subject Classification: 11D25, 11G05, 11Y50, 12D10. -
Mathematical Tripos Part III Lecture Courses in 2020-2021
Mathematical Tripos Part III Lecture Courses in 2020-2021 Department of Pure Mathematics & Mathematical Statistics Department of Applied Mathematics & Theoretical Physics Notes and Disclaimers. • Students may attend any combination of lectures but should note that it is not possible to take two courses for examination that are lectured in the same timetable slot. There is no requirement that students study only courses offered by one Department. • The code in parentheses after each course name indicates the term of the course (M: Michaelmas; L: Lent; E: Easter), and the number of lectures in the course. Unless indicated otherwise, a 16 lecture course is equivalent to 2 credit units, while a 24 lecture course is equivalent to 3 credit units. Please note that certain courses are non-examinable, and are indicated as such after the title. Some of these courses may be the basis for Part III essays. • At the start of some sections there is a paragraph indicating the desirable previous knowledge for courses in that section. On the one hand, such paragraphs are not exhaustive, whilst on the other, not all courses require all the pre-requisite material indicated. However you are strongly recommended to read up on the material with which you are unfamiliar if you intend to take a significant number of courses from a particular section. • The courses described in this document apply only for the academic year 2020-21. Details for subsequent years are often broadly similar, but not necessarily identical. The courses evolve from year to year. • Please note that while an attempt has been made to ensure that the outlines in this booklet are an accurate indication of the content of courses, the outlines do not constitute definitive syllabuses.