## MATH4NT Analytic Number Theory

Second Semester |

Number theory, which is probably the oldest branch of mathematics, is concerned with properties of integers. Of particular interest are prime numbers. Analytic number theory studies these using methods from analysis. This module gives a basic introduction with a focus on arithmetic functions, asymptotic formulae and the distribution of prime numbers.

### Period

2018, Semester 2.

### Prerequisites

MATH201.

MATH302 is recommended.

### Main topics

#### Fundamentals:

- divisibility, factors, prime numbers
- fundamental theorem of arithmetic
- various proofs of Euclid's theorem

#### Arithmetic functions:

- Dirichlet multiplication
- the Möbius inversion formula
- generalised convolutions
- Legendre's identity

#### Asymptotic formulae:

- big O notation and asymptotic equality
- Euler's summation formula and Abel's identity
- elementary asymptotic formulae
- Shapiro's Tauberian theorem

#### The distribution of prime numbers:

- the prime number theorem
- equivalent formulations
- bounds for the prime-counting function and the
*n*th prime

#### Riemann's zeta function:

- analytic continuation of the zeta function
- functional equation
- trivial and nontrivial zeros

### Lecturer

Dr Jörg Hennig, room 215, email: jhennig@maths.otago.ac.nz

Office hours: by arrangement (or just pop in if I am in my office).

### Assessment

There are three marked assignments and a final exam.

### Final mark

Your final mark F in the paper will be calculated according to this formula:

**F = 0.6E + 0.4A**

where:

- E is the Exam mark
- A is the Assignments mark

and all quantities are expressed as percentages.

### Students must abide by the University’s Academic Integrity Policy

**Academic endeavours at the University of Otago are built upon an essential commitment to academic integrity.**

The two most common forms of academic misconduct are *plagiarism* and *unauthorised collaboration*.

#### Academic misconduct: **Plagiarism**

Plagiarism is defined as:

- Copying or paraphrasing another person’s work and presenting it as your own.
- Being party to someone else’s plagiarism by letting them copy your work or helping them to copy the work of someone else without acknowledgement.
- Using your own work in another situation, such as for the assessment of a different paper or program, without indicating the source.
- Plagiarism can be unintentional or intentional. Even if it is unintentional, it is still considered to be plagiarism.

All students have a responsibility to be aware of acceptable academic practice in relation to the use of material prepared by others and are expected to take all steps reasonably necessary to ensure no breach of acceptable academic practice occurs. You should also be aware that plagiarism is easy to detect and the University has policies in place to deal with it.

#### Academic misconduct: **Unauthorised Collaboration**

Unauthorised Collaboration occurs when you work with, or share work with, others on an assessment which is designed as a task for individuals and in which individual answers are required. This form does not include assessment tasks where students are required or permitted to present their results as collaborative work. Nor does it preclude collaborative effort in research or study for assignments, tests or examinations; but unless it is explicitly stated otherwise, each student’s answers should be in their own words. If you are not sure if collaboration is allowed, check with your lecturer.

### Prime Number Theorem

The prime-counting function $\pi(x)$ gives the number of primes less than or equal to $x$. While this function is very irregular on small scales (top panel), it looks remarkably smooth on large scales (bottom panel). A central result in analytic number theory is the*Prime Number Theorem*, which states that $$\lim_{x\to\infty}\frac{\pi(x)}{x/\ln x}=1.$$