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Course11110113763 lectures

A Basic Course in Number Theory

Prof. Shripad Garge · IIT Bombay

Start with lecture 1 At NPTEL

About

This course intends to develop the basics of number theory touching upon many essential points such as the prime number theorem, quadratic reciprocity laws, Gauss’ theorem on the classification of binary quadratic forms, Brahmagupta-Pell equations, to quote a few. This course will enable a student to learn more advanced topics in number theory.

INTENDED AUDIENCE : Students with basic knowledge of Mathematics can take this course.

PREREQUISITES : Knowledge of basic group theory and ring theory will be useful but it is not necessary.

Lectures

Week 1

  1. Lecture 1 : Integers YouTube
  2. Lecture 2 : Divisibility and primes YouTube
  3. Lecture 3 : Infinitude of primes YouTube
  4. Lecture 4 : Division algorithm and the GCD YouTube
  5. Lecture 5 : Computing the GCD and Euclid’s lemma YouTube

Week 2

  1. Lecture 6 : Fundamental theorem of arithmetic YouTube
  2. Lecture 7 : Stories around primes YouTube
  3. Lecture 8 : Winding up on `Primes' and introducing `Congruences' YouTube
  4. Lecture 9 : Basic results in congruences YouTube
  5. Lecture 10 : Residue classes modulo n YouTube

Week 3

  1. Lecture 11 : Arithmetic modulo n, theory and examples YouTube
  2. Lecture 12 : Arithmetic modulo n, more examples YouTube
  3. Lecture 13 : Solving linear polynomials modulo n - I YouTube
  4. Lecture 14 : Solving linear polynomials modulo n - II YouTube
  5. Lecture 15 : Solving linear polynomials modulo n - III YouTube

Week 4

  1. Lecture 16 : Solving linear polynomials modulo n - IV YouTube
  2. Lecture 17 : Chinese remainder theorem, the initial cases YouTube
  3. Lecture 18 : Chinese remainder theorem, the general case and examples YouTube
  4. Lecture 19 : Chinese remainder theorem, more examples YouTube
  5. Lecture 20 : Using the CRT, square roots of 1 in ℤn YouTube

Week 5

  1. Lecture 21 : Wilson's theorem YouTube
  2. Lecture 22 : Roots of polynomials over ℤp YouTube
  3. Lecture 23 : Euler 𝜑-function - I YouTube
  4. Lecture 24 : Euler 𝜑-function - II YouTube
  5. Lecture 25 : Primitive roots - I YouTube

Week 6

  1. Lecture 26 : Primitive roots - II YouTube
  2. Lecture 27 : Primitive roots - III YouTube
  3. Lecture 28 : Primitive roots - IV YouTube
  4. Lecture 29 : Structure of Un - I YouTube
  5. Lecture 30 : Structure of Un - II YouTube

Week 7

  1. Lecture 31 : Quadratic residues YouTube
  2. Lecture 32 : The Legendre symbol YouTube
  3. Lecture 33 : Quadratic reciprocity law - I YouTube
  4. Lecture 34 : Quadratic reciprocity law - II YouTube
  5. Lecture 35 : Quadratic reciprocity law - III YouTube
  6. Lecture 36 : Quadratic reciprocity law - IV YouTube

Week 8

  1. Lecture 37 : The Jacobi symbol YouTube
  2. Lecture 38 : Binary quadratic forms YouTube
  3. Lecture 39 : Equivalence of binary quadratic forms YouTube
  4. Lecture 40 : Discriminant of a binary quadratic form YouTube
  5. Lecture 41 : Reduction theory of integral binary quadratic forms YouTube

Week 9

  1. Lecture 42 : Reduced forms up to equivalence - I YouTube
  2. Lecture 43 : Reduced forms up to equivalence - II YouTube
  3. Lecture 44 : Reduced forms up to equivalence - III YouTube
  4. Lecture 45 : Sums of squares - I YouTube
  5. Lecture 46 : Sums of squares - II YouTube
  6. Lecture 47 : Sums of squares - III YouTube

Week 10

  1. Lecture 48 : Beyond sums of squares - I YouTube
  2. Lecture 49 : Beyond sums of squares - II YouTube
  3. Lecture 50 : Continued fractions - basic results YouTube
  4. Lecture 51 : Dirichlet's approximation theorem YouTube
  5. Lecture 52 : Good rational approximations YouTube

Week 11

  1. Lecture 53 : Continued fraction expansion for real numbers - I YouTube
  2. Lecture 54 : Continued fraction expansion for real numbers - II YouTube
  3. Lecture 55 : Convergents give better approximations YouTube
  4. Lecture 56 : Convergents are the best approximations - I YouTube
  5. Lecture 57 : Convergents are the best approximations - II YouTube

Week 12

  1. Lecture 58 : Quadratic irrationals as continued fractions YouTube
  2. Lecture 59 : Some basics of algebraic number theory YouTube
  3. Lecture 60 : Units in quadratic fields: the imaginary case YouTube
  4. Lecture 61 : Units in quadratic fields: the real case YouTube
  5. Lecture 62 : Brahmagupta-Pell equations YouTube
  6. Lecture 63 : Tying some loose ends YouTube

Syllabus and materials

At NPTEL, as the course publishes them.

Credits and licence

Institution
IIT Bombay
Department
Mathematics
Teacher
Prof. Shripad Garge
Level
Graduate
Language
English
Subjects
Mathematics
Source
NPTEL
Licence
CC BY-NC-SA, as NPTEL states it. Non-commercial use only. NPTEL's terms
Attribution
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