Factoring Dickson polynomials over finite fields
|
|
- Laurel Bryant
- 8 years ago
- Views:
Transcription
1 Factoring Dickson polynomials over finite fiels Manjul Bhargava Department of Mathematics, Princeton University. Princeton NJ Michael Zieve Department of Mathematics, University of Southern California. Los Angeles CA Abstract We erive the factorizations of the Dickson polynomials D n X, a) an E n X, a), an of the bivariate Dickson polynomials D n X, a) D n Y, a), over any finite fiel. Our proofs are significantly shorter an more elementary than those previously known. 1. Introuction. Let F q be the fiel containing q elements, an let p be the characteristic of F q. Let n be a nonnegative integer an a F q. The Dickson polynomial of the first kin, of egree n an parameter a, is efine to be the unique polynomial D n X, a) F q [X] for which D n Y + a/y ), a) = Y n + a/y ) n ; the Dickson polynomial of the secon kin, of egree n an parameter a, is efine to be the unique polynomial E n X, a) F q [X] for which E n Y + a/y ), a) = Y n+1 a/y ) n+1. The uniqueness of these Y a/y ) polynomials is clear; there are several ways to prove their existence, e.g. see [1] or [5, Lemma 1.1] or [4, 2.2)]. These polynomials have been extensively stuie, an in fact a book has been written in their honor [4]. In this note we shall erive the factorizations of the Dickson polynomials D n X, a) an E n X, a), an of the bivariate Dickson polynomial D n X, a) D n Y, a), over any finite fiel F q. In each case, our strategy will be to first write own the 1
2 factorization over the algebraic closure F q of F q, then etermine how to put together certain factors over F q in orer to get the irreucible factors over F q. The factorizations of D n X, a) an E n X, a) have been carrie out using much lengthier methos by W.-S. Chou [2]. The purpose of this note is to exhibit a simpler approach. Our methos can also be use to provie simple proofs of various other factorization results; as an example we inclue the factorization of D n X, a) D n Y, a) over any finite fiel, which seems to be new. Previously the factorization of this polynomial over the algebraic closure of a finite fiel was known, ue to K. S. Williams for n o [7] an to G. Turnwal for n even [5, Prop. 1.7]; we give simpler proofs of these results as well. We are grateful to G. Turnwal for informing us that our proof of this last result is similar to an argument of S. D. Cohen an R. W. Matthews [3, p. 67]. We shall retain the notation of the first paragraph throughout this note. Also, for any ξ F q, by ξ we shall mean a fixe square root of ξ in F q ; for any positive integer coprime to p, we will use ζ to enote a primitive -th root of unity in F q. 2. The Dickson polynomial of the first kin, D n X, a). Write n = p r m with p, m) = 1. Then it follows from the functional equation of D n that D n X, a) = D m X, a) pr ; thus, in orer to factor D n, it suffices to factor D m. Our first result gives the factorization of D m over F q. Theorem 1 For q o, D m X, a) = 2m 1 i o X a ζ i 4m + ζ i 4m) ) ; for q even, D m X, a) = X 2 m 1 X a ζ i m + ζ i m ) ) 2. Proof. Note that D m Y + a Y, a) = Y m + a/y ) m = ξ m = 1 a ) Y ξ ; Y 2
3 in orer to express the right-han sie as a function of Y + a/y ), we pair the terms corresponing to ξ an 1/ξ, which gives Y ξ a ) Y a ) = Y 2 ξ + 1 )a + Y a2 Y ξy ξ Y = + a ) 2 1 ) 2. a ξ + ξ 2 Y Thus, D m X, a) is the prouct of monic linear factors corresponing to the ξ F q for which ξ m = 1, where the factors corresponing to ξ an 1/ξ are X ± a ξ + 1/ ξ)). The result for q even follows at once; for q o, the result follows from the fact that the numbers ± ξ with ξ m = 1 are precisely the numbers ζ i 4m with i o an 0 < i < 4m. For a = 0, the factorization of D m X, a) = X m is trivial; our next two results give the factorization of D m X, a) over F q when a 0. Theorem 2 If q is o an a 0, then D m X, a) is the prouct of several istinct irreucible polynomials in F q [X], which occur in cliques corresponing to the ivisors of m for which m/ is o. To each such there correspon ϕ4)/2n ) irreucible factors, each of which has the form N 1 X a qi ζ qi 4 + ) ) ζ qi 4 for some choice of ζ 4 ; here ϕ enotes Euler s totient function, k is the least positive integer such that q k ±1 mo 4), an k /2 if a / F q an k 2 mo 4) an q k/2 2 ± 1 mo 4); N = 2k if a / F q an k is o; otherwise. k Proof. The previous result escribes the roots of D m X, a); clearly these roots are istinct, since ξ an ξ 1 are the only roots of the quaratic equation Z + Z 1 = ξ + ξ 1. Thus D m X, a) is the prouct of its istinct monic irreucible factors over F q, an each such factor is the minimal polynomial over F q of a root α of D m. These roots are given by α = a ζ 4 + ζ 1 4 ) where is a ivisor of m with m/ o, an ζ 4 is a primitive 4-th root of unity. The minimal polynomial of α over F q has the form N 1 X αqi ), where N enotes the least positive integer such that α qn = α. We will show 3
4 that N = N ; since for fixe there are ϕ4)/2 choices for α, the theorem follows. We now show N = N. Note that a ζ4 + ζ 1 4 )) q s = a qs ζ qs 4 + ) ζ qs 4 ; thus, N is the least positive integer s such that q s a ζ qs 4 + ) ) ζ qs 4 = a ζ4 + ζ 1 4. ) If a F q or s is even, then a qs = a, so ) just asserts that ζ qs 4 + ζ qs 4 = ζ 4 + ζ 1 4, or equivalently ζqs 4 = ζ±1 4, i.e. qs ±1 mo 4). If a / F q an s is o, then a qs = a, so ) is equivalent to ζ qs 4 = ζ±1 4, i.e. qs 2 ± 1 mo 4). The result follows at once by inspection. Theorem 3 If q is even an a 0, then D m X, a)/x is the prouct of the squares of several istinct irreucible polynomials in F q [X], which occur in cliques corresponing to the ivisors of m with > 1. To each such there correspon ϕ)/2k ) irreucible factors, each of which has the form k 1 X a ζ qi + ) ) ζ qi for some choice of ζ ; here k is the least positive integer such that q k ±1 mo ). Proof. By Theorem 1, the roots of the polynomial D n X, a)/x are the elements α = a ζ + ζ 1 ) where m an 1. As in the proof of Theorem 2, we conclue D m X, a)/x is the prouct of its istinct monic irreucible factors over F q, an each such factor is of the form N 1 X αqi ), where N enotes the egree of α over F q. Since q is even, a F q implies a Fq ; thus N is the least positive integer s such that ζ qs +ζ qs = ζ +ζ 1, i.e., q s = ±1 mo ). Hence N = k. Since for fixe there are ϕ)/2 choices for α, we have the theorem. 3. The Dickson polynomial of the secon kin, E n X, a). Write n+1 in the form p r m + 1), where p, m + 1) = 1. Using the functional equation for E n, we fin E n Y + a/y, a) = Y m+1 a/y ) m+1 ) pr Y a/y = E m Y + a/y, a) pr Y a/y ) pr 1, 4
5 an it follows that E n X, a) = E m X, a) pr X 2 4a) pr 1 2. Thus, to factor E n, it suffices to factor E m. Our first result gives the factorization of E m over F q ; we omit the proof since it is nearly ientical to that of Theorem 1. Theorem 4 For q o, for q even, E m X, a) = m X a ζ i 2m+1) + ζ i 2m+1) )) ; m/2 E m X, a) = X a ζ i m+1 + ζm+1) ) i 2. When a = 0, the factorization of E m X, a) = X m is trivial. In Theorems 5 an 6, we present the factorization of E m X, a) over the finite fiel F q in the case a 0. Theorem 5 If q is o an a 0, then E m X, a) is the prouct of several istinct irreucible polynomials in F q [X]. These occur in cliques corresponing to the ivisors of 2m + 1) with > 2. To each such there correspon ϕ)/2n ) irreucible factors, each of which has the form N 1 X a qi ζ qi + ) ) ζ qi for some choice of ζ, unless a is a nonsquare in F q an 4 ; in this exceptional case there are ϕ)/n factors corresponing to each of = 0 an = 2 0, where 0 > 1 is an o ivisor of m + 1, an the factors corresponing to 0 are ientical to the factors corresponing to 2 0. Here k is the least positive integer such that q k ±1 mo ), an k /2 if a / F q an 0 mo 2) an k 2 mo 4) an q k/2 ± 1 mo ); 2 N = 2k if a / F q an k is o; otherwise. k 5
6 We omit the proof since it is similar to that of Theorem 2. We remark that the corresponing result in [2], namely Thm. 3.1, is false in case a is a square in F q an 4 ; this case shoul be inclue in item 5) of that result rather than item 6). Theorem 6 If q is even an a 0, then E m X, a) is the prouct of the squares of several istinct irreucible polynomials in F q [X], which occur in cliques corresponing to the ivisors of m + 1 with > 1. To each such there correspon ϕ)/2k ) irreucible factors, each of which has the form k 1 X a ζ qi + ) ) ζ qi for some choice of ζ ; here k is the least positive integer such that q k ±1 mo ). Proof. When the characteristic is 2, we observe that E m Y + a/y, a) = Y m+1 a/y ) m+1 Y a/y = D m+1y + a/y, a) ; Y + a/y hence E m X, a) = D m+1 X, a)/x, so the esire factorization follows immeiately from Theorem The bivariate Dickson polynomial, D n X, a) D n Y, a). Write n = p r m, where m, p) = 1. Then the functional equation implies D n X, a) D n Y, a) = [D m X, a) D m Y, a)] pr ; thus, to factor D n X, a) D n Y, a), it suffices to factor D m X, a) D m Y, a). As the factorization of D m X, 0) D m Y, 0) = X m Y m is trivial, we shall assume a 0 throughout. Our first result gives the factorization of D m X, a) D m Y, a) over F q. Theorem 7 Let α i = ζ i m + ζ i m D m X, a) D m Y, a) = X Y ) an for m even, an β i = ζ i m ζ i m. Then for m o, m 1)/2 D m X, a) D m Y, a) = X Y )X + Y ) 6 X 2 α i XY + Y 2 + β 2 i a ), m 2)/2 X 2 α i XY + Y 2 + β 2 i a ).
7 Proof. Observe that a D m W + W, a) a D m Z + Z, a) = W m + a/w ) m Z m a/z) m [ a ) m ] = [W m Z m ] = ξ m =1 1 [ W Z W ) ξz 1 ξ a W Z )]. In orer to express the last expression as a function solely of W + a/w an Z + a/z, we pair the terms corresponing to ξ an 1/ξ; writing α = ξ + ξ 1 an β = ξ ξ 1, this gives = ) W ξz 1 ξ a W Z W + a ) 2 α W + a W W if ξ 1/ξ i.e. ξ ±1), an ) W ξz 1 ξ a ) = W Z ) W Z ) 1 a ξ ) Z + a ) + Z ) ξw Z Z + a ) 2 + β 2 a Z W + a ) ξ Z + a ) W Z otherwise. The factorization given in the theorem follows at once. Moreover, one can immeiately check that the given linear an quaratic factors are irreucible over F q ; hence the state factorization is complete. Our next result gives the factorization of D m X, a) D m Y, a) over F q. Theorem 8 The polynomial D m X, a) D m Y, a) is the prouct of istinct irreucible polynomials in F q [X], which occur in cliques corresponing to the ivisors of m. To each such 1, 2 there correspon ϕ)/2k ) irreucible factors of egree 2k, each of which has the form k 1 X 2 α qi XY + Y 2 + β 2qi a). For {1, 2}, there correspons a single factor of the form X ζ Y ). Here α an β enote ζ + ζ 1 an ζ ζ 1 respectively for some choice of ζ, an k is the least positive integer such that q k ±1 mo ). 7
8 Proof. Note that the quaratic factors of D m X, a) D m Y, a) over F q as given in the previous theorem are istinct, since α 1,..., α m 1)/2 are istinct. Hence D m X, a) D m Y, a) is the prouct of its istinct monic irreucible factors over F q, an each such factor is either of the form X ζ Y ) for = 1 or 2, or is of the form N 1 X 2 α qi XY + Y 2 + β 2qi a), for some m with > 2, where N enotes the least positive integer such that both α an β 2 are elements of F q N. However, note that β2 = α2 4 F q α ), an, as before, the smallest integer M such that α qm = α is M = k. Hence N = k, an the theorem follows. Remark. There oes not appear to be an analogous way to treat the bivariate Dickson polynomial E n X, a) E n Y, a) of the secon kin, an in fact little is known about this factorization, although G. Turnwal has some preliminary results [6]. Finally, we mention one further factorization involving Dickson polynomials: q 1 E i X, 1)Y q 1)q 1 i) = a F q [D q 1 Y, a) X]. Many further results along these lines can be foun in [1]. Acknowlegments. That the arguments presente in [2] can be greatly simplifie has been inepenently notice by S. Gao private communication). The first author acknowleges support from AT&T Research uring the summer of The secon author was supporte by an NSF Postoctoral Fellowship. References [1] S. S. Abhyankar, S. D. Cohen, an M. E. Zieve, Bivariate factorizations connecting Dickson polynomials an Galois theory, Trans. Amer. Math. Soc., to appear. [2] W. Chou, The factorization of Dickson polynomials over finite fiels, Finite Fiels Appl ),
9 [3] S. D. Cohen an R. W. Matthews, Monoromy groups of classical families over finite fiels, in Finite Fiels an Applications, LMS Lecture Note Series, Vol. 233, pp , Cambrige, [4] R. Lil, G. L. Mullen, an G. Turnwal, Dickson Polynomials, Pitman Monographs an Surveys in Pure an Applie Math.,Longman, Lonon/Harlow/Essex, [5] G. Turnwal, On Schur s conjecture, J. Austral. Math. Soc. Ser. A) ), [6] G. Turnwal, Monoromy groups of Dickson polynomials of the secon kin, preprint, [7] K. S. Williams, Note on Dickson s permutation polynomials, Duke Math. J ),
Pythagorean Triples Over Gaussian Integers
International Journal of Algebra, Vol. 6, 01, no., 55-64 Pythagorean Triples Over Gaussian Integers Cheranoot Somboonkulavui 1 Department of Mathematics, Faculty of Science Chulalongkorn University Bangkok
More informationCONTINUED FRACTIONS AND PELL S EQUATION. Contents 1. Continued Fractions 1 2. Solution to Pell s Equation 9 References 12
CONTINUED FRACTIONS AND PELL S EQUATION SEUNG HYUN YANG Abstract. In this REU paper, I will use some important characteristics of continued fractions to give the complete set of solutions to Pell s equation.
More informationFACTORING POLYNOMIALS IN THE RING OF FORMAL POWER SERIES OVER Z
FACTORING POLYNOMIALS IN THE RING OF FORMAL POWER SERIES OVER Z DANIEL BIRMAJER, JUAN B GIL, AND MICHAEL WEINER Abstract We consider polynomials with integer coefficients and discuss their factorization
More informationCyclotomic Extensions
Chapter 7 Cyclotomic Extensions A cyclotomic extension Q(ζ n ) of the rationals is formed by adjoining a primitive n th root of unity ζ n. In this chapter, we will find an integral basis and calculate
More informationContinued Fractions and the Euclidean Algorithm
Continued Fractions and the Euclidean Algorithm Lecture notes prepared for MATH 326, Spring 997 Department of Mathematics and Statistics University at Albany William F Hammond Table of Contents Introduction
More informationminimal polyonomial Example
Minimal Polynomials Definition Let α be an element in GF(p e ). We call the monic polynomial of smallest degree which has coefficients in GF(p) and α as a root, the minimal polyonomial of α. Example: We
More informationExponential Functions: Differentiation and Integration. The Natural Exponential Function
46_54.q //4 :59 PM Page 5 5 CHAPTER 5 Logarithmic, Eponential, an Other Transcenental Functions Section 5.4 f () = e f() = ln The inverse function of the natural logarithmic function is the natural eponential
More informationIntroduction to Finite Fields (cont.)
Chapter 6 Introduction to Finite Fields (cont.) 6.1 Recall Theorem. Z m is a field m is a prime number. Theorem (Subfield Isomorphic to Z p ). Every finite field has the order of a power of a prime number
More informationFirewall Design: Consistency, Completeness, and Compactness
C IS COS YS TE MS Firewall Design: Consistency, Completeness, an Compactness Mohame G. Goua an Xiang-Yang Alex Liu Department of Computer Sciences The University of Texas at Austin Austin, Texas 78712-1188,
More information1 = (a 0 + b 0 α) 2 + + (a m 1 + b m 1 α) 2. for certain elements a 0,..., a m 1, b 0,..., b m 1 of F. Multiplying out, we obtain
Notes on real-closed fields These notes develop the algebraic background needed to understand the model theory of real-closed fields. To understand these notes, a standard graduate course in algebra is
More informationA Generalization of Sauer s Lemma to Classes of Large-Margin Functions
A Generalization of Sauer s Lemma to Classes of Large-Margin Functions Joel Ratsaby University College Lonon Gower Street, Lonon WC1E 6BT, Unite Kingom J.Ratsaby@cs.ucl.ac.uk, WWW home page: http://www.cs.ucl.ac.uk/staff/j.ratsaby/
More informationLOW-DEGREE PLANAR MONOMIALS IN CHARACTERISTIC TWO
LOW-DEGREE PLANAR MONOMIALS IN CHARACTERISTIC TWO PETER MÜLLER AND MICHAEL E. ZIEVE Abstract. Planar functions over finite fields give rise to finite projective planes and other combinatorial objects.
More informationBV has the bounded approximation property
The Journal of Geometric Analysis volume 15 (2005), number 1, pp. 1-7 [version, April 14, 2005] BV has the boune approximation property G. Alberti, M. Csörnyei, A. Pe lczyński, D. Preiss Abstract: We prove
More informationThe Australian Journal of Mathematical Analysis and Applications
The Australian Journal of Mathematical Analysis and Applications Volume 7, Issue, Article 11, pp. 1-14, 011 SOME HOMOGENEOUS CYCLIC INEQUALITIES OF THREE VARIABLES OF DEGREE THREE AND FOUR TETSUYA ANDO
More informationOn the largest prime factor of x 2 1
On the largest prime factor of x 2 1 Florian Luca and Filip Najman Abstract In this paper, we find all integers x such that x 2 1 has only prime factors smaller than 100. This gives some interesting numerical
More informationCHAPTER SIX IRREDUCIBILITY AND FACTORIZATION 1. BASIC DIVISIBILITY THEORY
January 10, 2010 CHAPTER SIX IRREDUCIBILITY AND FACTORIZATION 1. BASIC DIVISIBILITY THEORY The set of polynomials over a field F is a ring, whose structure shares with the ring of integers many characteristics.
More informationMath 230.01, Fall 2012: HW 1 Solutions
Math 3., Fall : HW Solutions Problem (p.9 #). Suppose a wor is picke at ranom from this sentence. Fin: a) the chance the wor has at least letters; SOLUTION: All wors are equally likely to be chosen. The
More informationSign changes of Hecke eigenvalues of Siegel cusp forms of degree 2
Sign changes of Hecke eigenvalues of Siegel cusp forms of degree 2 Ameya Pitale, Ralf Schmidt 2 Abstract Let µ(n), n > 0, be the sequence of Hecke eigenvalues of a cuspidal Siegel eigenform F of degree
More informationPrime Numbers and Irreducible Polynomials
Prime Numbers and Irreducible Polynomials M. Ram Murty The similarity between prime numbers and irreducible polynomials has been a dominant theme in the development of number theory and algebraic geometry.
More informationON GALOIS REALIZATIONS OF THE 2-COVERABLE SYMMETRIC AND ALTERNATING GROUPS
ON GALOIS REALIZATIONS OF THE 2-COVERABLE SYMMETRIC AND ALTERNATING GROUPS DANIEL RABAYEV AND JACK SONN Abstract. Let f(x) be a monic polynomial in Z[x] with no rational roots but with roots in Q p for
More informationFACTORING IN THE HYPERELLIPTIC TORELLI GROUP
FACTORING IN THE HYPERELLIPTIC TORELLI GROUP TARA E. BRENDLE AND DAN MARGALIT Abstract. The hyperelliptic Torelli group is the subgroup of the mapping class group consisting of elements that act trivially
More informationAMBIGUOUS CLASSES IN QUADRATIC FIELDS
MATHEMATICS OF COMPUTATION VOLUME, NUMBER 0 JULY 99, PAGES -0 AMBIGUOUS CLASSES IN QUADRATIC FIELDS R. A. MOLLIN Dedicated to the memory ofd. H. Lehmer Abstract. We provide sufficient conditions for the
More informationPRIME FACTORS OF CONSECUTIVE INTEGERS
PRIME FACTORS OF CONSECUTIVE INTEGERS MARK BAUER AND MICHAEL A. BENNETT Abstract. This note contains a new algorithm for computing a function f(k) introduced by Erdős to measure the minimal gap size in
More informationHOMEWORK 5 SOLUTIONS. n!f n (1) lim. ln x n! + xn x. 1 = G n 1 (x). (2) k + 1 n. (n 1)!
Math 7 Fall 205 HOMEWORK 5 SOLUTIONS Problem. 2008 B2 Let F 0 x = ln x. For n 0 and x > 0, let F n+ x = 0 F ntdt. Evaluate n!f n lim n ln n. By directly computing F n x for small n s, we obtain the following
More informationON GENERALIZED RELATIVE COMMUTATIVITY DEGREE OF A FINITE GROUP. A. K. Das and R. K. Nath
International Electronic Journal of Algebra Volume 7 (2010) 140-151 ON GENERALIZED RELATIVE COMMUTATIVITY DEGREE OF A FINITE GROUP A. K. Das and R. K. Nath Received: 12 October 2009; Revised: 15 December
More informationEvery Positive Integer is the Sum of Four Squares! (and other exciting problems)
Every Positive Integer is the Sum of Four Squares! (and other exciting problems) Sophex University of Texas at Austin October 18th, 00 Matilde N. Lalín 1. Lagrange s Theorem Theorem 1 Every positive integer
More informationLecture 13 - Basic Number Theory.
Lecture 13 - Basic Number Theory. Boaz Barak March 22, 2010 Divisibility and primes Unless mentioned otherwise throughout this lecture all numbers are non-negative integers. We say that A divides B, denoted
More informationInteger roots of quadratic and cubic polynomials with integer coefficients
Integer roots of quadratic and cubic polynomials with integer coefficients Konstantine Zelator Mathematics, Computer Science and Statistics 212 Ben Franklin Hall Bloomsburg University 400 East Second Street
More informationCS 103X: Discrete Structures Homework Assignment 3 Solutions
CS 103X: Discrete Structures Homework Assignment 3 s Exercise 1 (20 points). On well-ordering and induction: (a) Prove the induction principle from the well-ordering principle. (b) Prove the well-ordering
More informationA simple criterion on degree sequences of graphs
Discrete Applied Mathematics 156 (2008) 3513 3517 Contents lists available at ScienceDirect Discrete Applied Mathematics journal homepage: www.elsevier.com/locate/dam Note A simple criterion on degree
More informationRow Ideals and Fibers of Morphisms
Michigan Math. J. 57 (2008) Row Ideals and Fibers of Morphisms David Eisenbud & Bernd Ulrich Affectionately dedicated to Mel Hochster, who has been an inspiration to us for many years, on the occasion
More informationa 11 x 1 + a 12 x 2 + + a 1n x n = b 1 a 21 x 1 + a 22 x 2 + + a 2n x n = b 2.
Chapter 1 LINEAR EQUATIONS 1.1 Introduction to linear equations A linear equation in n unknowns x 1, x,, x n is an equation of the form a 1 x 1 + a x + + a n x n = b, where a 1, a,..., a n, b are given
More informationThe Notebook Series. The solution of cubic and quartic equations. R.S. Johnson. Professor of Applied Mathematics
The Notebook Series The solution of cubic and quartic equations by R.S. Johnson Professor of Applied Mathematics School of Mathematics & Statistics University of Newcastle upon Tyne R.S.Johnson 006 CONTENTS
More informationKevin James. MTHSC 412 Section 2.4 Prime Factors and Greatest Comm
MTHSC 412 Section 2.4 Prime Factors and Greatest Common Divisor Greatest Common Divisor Definition Suppose that a, b Z. Then we say that d Z is a greatest common divisor (gcd) of a and b if the following
More informationModule MA3411: Abstract Algebra Galois Theory Appendix Michaelmas Term 2013
Module MA3411: Abstract Algebra Galois Theory Appendix Michaelmas Term 2013 D. R. Wilkins Copyright c David R. Wilkins 1997 2013 Contents A Cyclotomic Polynomials 79 A.1 Minimum Polynomials of Roots of
More informationMASSACHUSETTS INSTITUTE OF TECHNOLOGY 6.436J/15.085J Fall 2008 Lecture 14 10/27/2008 MOMENT GENERATING FUNCTIONS
MASSACHUSETTS INSTITUTE OF TECHNOLOGY 6.436J/15.085J Fall 2008 Lecture 14 10/27/2008 MOMENT GENERATING FUNCTIONS Contents 1. Moment generating functions 2. Sum of a ranom number of ranom variables 3. Transforms
More informationPrime numbers and prime polynomials. Paul Pollack Dartmouth College
Prime numbers and prime polynomials Paul Pollack Dartmouth College May 1, 2008 Analogies everywhere! Analogies in elementary number theory (continued fractions, quadratic reciprocity, Fermat s last theorem)
More informationQUADRATIC RECIPROCITY IN CHARACTERISTIC 2
QUADRATIC RECIPROCITY IN CHARACTERISTIC 2 KEITH CONRAD 1. Introduction Let F be a finite field. When F has odd characteristic, the quadratic reciprocity law in F[T ] (see [4, Section 3.2.2] or [5]) lets
More information2r 1. Definition (Degree Measure). Let G be a r-graph of order n and average degree d. Let S V (G). The degree measure µ(s) of S is defined by,
Theorem Simple Containers Theorem) Let G be a simple, r-graph of average egree an of orer n Let 0 < δ < If is large enough, then there exists a collection of sets C PV G)) satisfying: i) for every inepenent
More informationMannheim curves in the three-dimensional sphere
Mannheim curves in the three-imensional sphere anju Kahraman, Mehmet Öner Manisa Celal Bayar University, Faculty of Arts an Sciences, Mathematics Department, Muraiye Campus, 5, Muraiye, Manisa, urkey.
More informationMathematics. Circles. hsn.uk.net. Higher. Contents. Circles 119 HSN22400
hsn.uk.net Higher Mathematics UNIT OUTCOME 4 Circles Contents Circles 119 1 Representing a Circle 119 Testing a Point 10 3 The General Equation of a Circle 10 4 Intersection of a Line an a Circle 1 5 Tangents
More informationIntroduction to Algebraic Geometry. Bézout s Theorem and Inflection Points
Introduction to Algebraic Geometry Bézout s Theorem and Inflection Points 1. The resultant. Let K be a field. Then the polynomial ring K[x] is a unique factorisation domain (UFD). Another example of a
More information10.2 Systems of Linear Equations: Matrices
SECTION 0.2 Systems of Linear Equations: Matrices 7 0.2 Systems of Linear Equations: Matrices OBJECTIVES Write the Augmente Matrix of a System of Linear Equations 2 Write the System from the Augmente Matrix
More informationHomework until Test #2
MATH31: Number Theory Homework until Test # Philipp BRAUN Section 3.1 page 43, 1. It has been conjectured that there are infinitely many primes of the form n. Exhibit five such primes. Solution. Five such
More informationJUST THE MATHS UNIT NUMBER 1.8. ALGEBRA 8 (Polynomials) A.J.Hobson
JUST THE MATHS UNIT NUMBER 1.8 ALGEBRA 8 (Polynomials) by A.J.Hobson 1.8.1 The factor theorem 1.8.2 Application to quadratic and cubic expressions 1.8.3 Cubic equations 1.8.4 Long division of polynomials
More informationOptimal Control Of Production Inventory Systems With Deteriorating Items And Dynamic Costs
Applie Mathematics E-Notes, 8(2008), 194-202 c ISSN 1607-2510 Available free at mirror sites of http://www.math.nthu.eu.tw/ amen/ Optimal Control Of Prouction Inventory Systems With Deteriorating Items
More informationk, then n = p2α 1 1 pα k
Powers of Integers An integer n is a perfect square if n = m for some integer m. Taking into account the prime factorization, if m = p α 1 1 pα k k, then n = pα 1 1 p α k k. That is, n is a perfect square
More informationElliptic Functions sn, cn, dn, as Trigonometry W. Schwalm, Physics, Univ. N. Dakota
Elliptic Functions sn, cn, n, as Trigonometry W. Schwalm, Physics, Univ. N. Dakota Backgroun: Jacobi iscovere that rather than stuying elliptic integrals themselves, it is simpler to think of them as inverses
More informationA Comparison of Performance Measures for Online Algorithms
A Comparison of Performance Measures for Online Algorithms Joan Boyar 1, Sany Irani 2, an Kim S. Larsen 1 1 Department of Mathematics an Computer Science, University of Southern Denmark, Campusvej 55,
More information7. Some irreducible polynomials
7. Some irreducible polynomials 7.1 Irreducibles over a finite field 7.2 Worked examples Linear factors x α of a polynomial P (x) with coefficients in a field k correspond precisely to roots α k [1] of
More informationInverse Trig Functions
Inverse Trig Functions c A Math Support Center Capsule February, 009 Introuction Just as trig functions arise in many applications, so o the inverse trig functions. What may be most surprising is that
More informationarxiv:math/0606467v2 [math.co] 5 Jul 2006
A Conjectured Combinatorial Interpretation of the Normalized Irreducible Character Values of the Symmetric Group arxiv:math/0606467v [math.co] 5 Jul 006 Richard P. Stanley Department of Mathematics, Massachusetts
More informationIRREDUCIBLE OPERATOR SEMIGROUPS SUCH THAT AB AND BA ARE PROPORTIONAL. 1. Introduction
IRREDUCIBLE OPERATOR SEMIGROUPS SUCH THAT AB AND BA ARE PROPORTIONAL R. DRNOVŠEK, T. KOŠIR Dedicated to Prof. Heydar Radjavi on the occasion of his seventieth birthday. Abstract. Let S be an irreducible
More informationInner Product Spaces
Math 571 Inner Product Spaces 1. Preliminaries An inner product space is a vector space V along with a function, called an inner product which associates each pair of vectors u, v with a scalar u, v, and
More informationThe cyclotomic polynomials
The cyclotomic polynomials Notes by G.J.O. Jameson 1. The definition and general results We use the notation e(t) = e 2πit. Note that e(n) = 1 for integers n, e(s + t) = e(s)e(t) for all s, t. e( 1 ) =
More informationZeros of a Polynomial Function
Zeros of a Polynomial Function An important consequence of the Factor Theorem is that finding the zeros of a polynomial is really the same thing as factoring it into linear factors. In this section we
More informationPYTHAGOREAN TRIPLES KEITH CONRAD
PYTHAGOREAN TRIPLES KEITH CONRAD 1. Introduction A Pythagorean triple is a triple of positive integers (a, b, c) where a + b = c. Examples include (3, 4, 5), (5, 1, 13), and (8, 15, 17). Below is an ancient
More informationMATH10040 Chapter 2: Prime and relatively prime numbers
MATH10040 Chapter 2: Prime and relatively prime numbers Recall the basic definition: 1. Prime numbers Definition 1.1. Recall that a positive integer is said to be prime if it has precisely two positive
More informationMax-Min Representation of Piecewise Linear Functions
Beiträge zur Algebra und Geometrie Contributions to Algebra and Geometry Volume 43 (2002), No. 1, 297-302. Max-Min Representation of Piecewise Linear Functions Sergei Ovchinnikov Mathematics Department,
More informationRECURSIVE ENUMERATION OF PYTHAGOREAN TRIPLES
RECURSIVE ENUMERATION OF PYTHAGOREAN TRIPLES DARRYL MCCULLOUGH AND ELIZABETH WADE In [9], P. W. Wade and W. R. Wade (no relation to the second author gave a recursion formula that produces Pythagorean
More informationON FIBONACCI NUMBERS WITH FEW PRIME DIVISORS
ON FIBONACCI NUMBERS WITH FEW PRIME DIVISORS YANN BUGEAUD, FLORIAN LUCA, MAURICE MIGNOTTE, SAMIR SIKSEK Abstract If n is a positive integer, write F n for the nth Fibonacci number, and ω(n) for the number
More informationOn the representability of the bi-uniform matroid
On the representability of the bi-uniform matroid Simeon Ball, Carles Padró, Zsuzsa Weiner and Chaoping Xing August 3, 2012 Abstract Every bi-uniform matroid is representable over all sufficiently large
More informationContinuity of the Perron Root
Linear and Multilinear Algebra http://dx.doi.org/10.1080/03081087.2014.934233 ArXiv: 1407.7564 (http://arxiv.org/abs/1407.7564) Continuity of the Perron Root Carl D. Meyer Department of Mathematics, North
More informationExample Optimization Problems selected from Section 4.7
Example Optimization Problems selecte from Section 4.7 19) We are aske to fin the points ( X, Y ) on the ellipse 4x 2 + y 2 = 4 that are farthest away from the point ( 1, 0 ) ; as it happens, this point
More informationDifferentiability of Exponential Functions
Differentiability of Exponential Functions Philip M. Anselone an John W. Lee Philip Anselone (panselone@actionnet.net) receive his Ph.D. from Oregon State in 1957. After a few years at Johns Hopkins an
More informationIndiana State Core Curriculum Standards updated 2009 Algebra I
Indiana State Core Curriculum Standards updated 2009 Algebra I Strand Description Boardworks High School Algebra presentations Operations With Real Numbers Linear Equations and A1.1 Students simplify and
More informationTHE NUMBER OF REPRESENTATIONS OF n OF THE FORM n = x 2 2 y, x > 0, y 0
THE NUMBER OF REPRESENTATIONS OF n OF THE FORM n = x 2 2 y, x > 0, y 0 RICHARD J. MATHAR Abstract. We count solutions to the Ramanujan-Nagell equation 2 y +n = x 2 for fixed positive n. The computational
More informationNotes on tangents to parabolas
Notes on tangents to parabolas (These are notes for a talk I gave on 2007 March 30.) The point of this talk is not to publicize new results. The most recent material in it is the concept of Bézier curves,
More informationModern Algebra Lecture Notes: Rings and fields set 4 (Revision 2)
Modern Algebra Lecture Notes: Rings and fields set 4 (Revision 2) Kevin Broughan University of Waikato, Hamilton, New Zealand May 13, 2010 Remainder and Factor Theorem 15 Definition of factor If f (x)
More informationAssociativity condition for some alternative algebras of degree three
Associativity condition for some alternative algebras of degree three Mirela Stefanescu and Cristina Flaut Abstract In this paper we find an associativity condition for a class of alternative algebras
More information15. Symmetric polynomials
15. Symmetric polynomials 15.1 The theorem 15.2 First examples 15.3 A variant: discriminants 1. The theorem Let S n be the group of permutations of {1,, n}, also called the symmetric group on n things.
More informationUNIFIED BIJECTIONS FOR MAPS WITH PRESCRIBED DEGREES AND GIRTH
UNIFIED BIJECTIONS FOR MAPS WITH PRESCRIBED DEGREES AND GIRTH OLIVIER BERNARDI AND ÉRIC FUSY Abstract. This article presents unifie bijective constructions for planar maps, with control on the face egrees
More informationU.C. Berkeley CS276: Cryptography Handout 0.1 Luca Trevisan January, 2009. Notes on Algebra
U.C. Berkeley CS276: Cryptography Handout 0.1 Luca Trevisan January, 2009 Notes on Algebra These notes contain as little theory as possible, and most results are stated without proof. Any introductory
More information= 2 + 1 2 2 = 3 4, Now assume that P (k) is true for some fixed k 2. This means that
Instructions. Answer each of the questions on your own paper, and be sure to show your work so that partial credit can be adequately assessed. Credit will not be given for answers (even correct ones) without
More informationSHARP BOUNDS FOR THE SUM OF THE SQUARES OF THE DEGREES OF A GRAPH
31 Kragujevac J. Math. 25 (2003) 31 49. SHARP BOUNDS FOR THE SUM OF THE SQUARES OF THE DEGREES OF A GRAPH Kinkar Ch. Das Department of Mathematics, Indian Institute of Technology, Kharagpur 721302, W.B.,
More informationMSc. Econ: MATHEMATICAL STATISTICS, 1995 MAXIMUM-LIKELIHOOD ESTIMATION
MAXIMUM-LIKELIHOOD ESTIMATION The General Theory of M-L Estimation In orer to erive an M-L estimator, we are boun to make an assumption about the functional form of the istribution which generates the
More information3 1. Note that all cubes solve it; therefore, there are no more
Math 13 Problem set 5 Artin 11.4.7 Factor the following polynomials into irreducible factors in Q[x]: (a) x 3 3x (b) x 3 3x + (c) x 9 6x 6 + 9x 3 3 Solution: The first two polynomials are cubics, so if
More informationAN ALGORITHM FOR DETERMINING WHETHER A GIVEN BINARY MATROID IS GRAPHIC
AN ALGORITHM FOR DETERMINING WHETHER A GIVEN BINARY MATROID IS GRAPHIC W. T. TUTTE. Introduction. In a recent series of papers [l-4] on graphs and matroids I used definitions equivalent to the following.
More informationHere the units used are radians and sin x = sin(x radians). Recall that sin x and cos x are defined and continuous everywhere and
Lecture 9 : Derivatives of Trigonometric Functions (Please review Trigonometry uner Algebra/Precalculus Review on the class webpage.) In this section we will look at the erivatives of the trigonometric
More informationOSTROWSKI FOR NUMBER FIELDS
OSTROWSKI FOR NUMBER FIELDS KEITH CONRAD Ostrowski classified the nontrivial absolute values on Q: up to equivalence, they are the usual (archimedean) absolute value and the p-adic absolute values for
More informationFACTORISATION YEARS. A guide for teachers - Years 9 10 June 2011. The Improving Mathematics Education in Schools (TIMES) Project
9 10 YEARS The Improving Mathematics Education in Schools (TIMES) Project FACTORISATION NUMBER AND ALGEBRA Module 33 A guide for teachers - Years 9 10 June 2011 Factorisation (Number and Algebra : Module
More informationMath 345-60 Abstract Algebra I Questions for Section 23: Factoring Polynomials over a Field
Math 345-60 Abstract Algebra I Questions for Section 23: Factoring Polynomials over a Field 1. Throughout this section, F is a field and F [x] is the ring of polynomials with coefficients in F. We will
More informationa 1 x + a 0 =0. (3) ax 2 + bx + c =0. (4)
ROOTS OF POLYNOMIAL EQUATIONS In this unit we discuss polynomial equations. A polynomial in x of degree n, where n 0 is an integer, is an expression of the form P n (x) =a n x n + a n 1 x n 1 + + a 1 x
More informationRINGS WITH A POLYNOMIAL IDENTITY
RINGS WITH A POLYNOMIAL IDENTITY IRVING KAPLANSKY 1. Introduction. In connection with his investigation of projective planes, M. Hall [2, Theorem 6.2]* proved the following theorem: a division ring D in
More informationWeb Appendices to Selling to Overcon dent Consumers
Web Appenices to Selling to Overcon ent Consumers Michael D. Grubb MIT Sloan School of Management Cambrige, MA 02142 mgrubbmit.eu www.mit.eu/~mgrubb May 2, 2008 B Option Pricing Intuition This appenix
More informationWeb Appendices of Selling to Overcon dent Consumers
Web Appenices of Selling to Overcon ent Consumers Michael D. Grubb A Option Pricing Intuition This appenix provies aitional intuition base on option pricing for the result in Proposition 2. Consier the
More informationIntroduction to Integration Part 1: Anti-Differentiation
Mathematics Learning Centre Introuction to Integration Part : Anti-Differentiation Mary Barnes c 999 University of Syney Contents For Reference. Table of erivatives......2 New notation.... 2 Introuction
More informationMATH 423 Linear Algebra II Lecture 38: Generalized eigenvectors. Jordan canonical form (continued).
MATH 423 Linear Algebra II Lecture 38: Generalized eigenvectors Jordan canonical form (continued) Jordan canonical form A Jordan block is a square matrix of the form λ 1 0 0 0 0 λ 1 0 0 0 0 λ 0 0 J = 0
More informationHow To Prove The Dirichlet Unit Theorem
Chapter 6 The Dirichlet Unit Theorem As usual, we will be working in the ring B of algebraic integers of a number field L. Two factorizations of an element of B are regarded as essentially the same if
More informationSUBGROUPS OF CYCLIC GROUPS. 1. Introduction In a group G, we denote the (cyclic) group of powers of some g G by
SUBGROUPS OF CYCLIC GROUPS KEITH CONRAD 1. Introduction In a group G, we denote the (cyclic) group of powers of some g G by g = {g k : k Z}. If G = g, then G itself is cyclic, with g as a generator. Examples
More informationBipan Hazarika ON ACCELERATION CONVERGENCE OF MULTIPLE SEQUENCES. 1. Introduction
F A S C I C U L I M A T H E M A T I C I Nr 51 2013 Bipan Hazarika ON ACCELERATION CONVERGENCE OF MULTIPLE SEQUENCES Abstract. In this article the notion of acceleration convergence of double sequences
More informationPowers of Two in Generalized Fibonacci Sequences
Revista Colombiana de Matemáticas Volumen 462012)1, páginas 67-79 Powers of Two in Generalized Fibonacci Sequences Potencias de dos en sucesiones generalizadas de Fibonacci Jhon J. Bravo 1,a,B, Florian
More informationPUTNAM TRAINING POLYNOMIALS. Exercises 1. Find a polynomial with integral coefficients whose zeros include 2 + 5.
PUTNAM TRAINING POLYNOMIALS (Last updated: November 17, 2015) Remark. This is a list of exercises on polynomials. Miguel A. Lerma Exercises 1. Find a polynomial with integral coefficients whose zeros include
More informationWinter Camp 2011 Polynomials Alexander Remorov. Polynomials. Alexander Remorov alexanderrem@gmail.com
Polynomials Alexander Remorov alexanderrem@gmail.com Warm-up Problem 1: Let f(x) be a quadratic polynomial. Prove that there exist quadratic polynomials g(x) and h(x) such that f(x)f(x + 1) = g(h(x)).
More information1 Lecture: Integration of rational functions by decomposition
Lecture: Integration of rational functions by decomposition into partial fractions Recognize and integrate basic rational functions, except when the denominator is a power of an irreducible quadratic.
More informationSimilarity and Diagonalization. Similar Matrices
MATH022 Linear Algebra Brief lecture notes 48 Similarity and Diagonalization Similar Matrices Let A and B be n n matrices. We say that A is similar to B if there is an invertible n n matrix P such that
More informationSince [L : K(α)] < [L : K] we know from the inductive assumption that [L : K(α)] s < [L : K(α)]. It follows now from Lemma 6.
Theorem 7.1. Let L K be a finite extension. Then a)[l : K] [L : K] s b) the extension L K is separable iff [L : K] = [L : K] s. Proof. Let M be a normal closure of L : K. Consider first the case when L
More informationLagrangian and Hamiltonian Mechanics
Lagrangian an Hamiltonian Mechanics D.G. Simpson, Ph.D. Department of Physical Sciences an Engineering Prince George s Community College December 5, 007 Introuction In this course we have been stuying
More informationSYSTEMS OF PYTHAGOREAN TRIPLES. Acknowledgements. I would like to thank Professor Laura Schueller for advising and guiding me
SYSTEMS OF PYTHAGOREAN TRIPLES CHRISTOPHER TOBIN-CAMPBELL Abstract. This paper explores systems of Pythagorean triples. It describes the generating formulas for primitive Pythagorean triples, determines
More informationOptimal Control Policy of a Production and Inventory System for multi-product in Segmented Market
RATIO MATHEMATICA 25 (2013), 29 46 ISSN:1592-7415 Optimal Control Policy of a Prouction an Inventory System for multi-prouct in Segmente Market Kuleep Chauhary, Yogener Singh, P. C. Jha Department of Operational
More information