| October 5 |
The constant in Mertens' product theorem. The guesstimates of Legendre and Gauss for counts of primes. |
| October 2 |
Mertens' sum theorem. Mertens' product theorem. |
| September 30 |
Montgomery--Wagon's heuristic for the PNT, continued. How not to prove the PNT. |
| September 28 |
Start of discussion of Montgomery--Wagon's heuristic for the PNT. |
| September 21 |
Proof of Bertrand's postulate in the following asymptotic form: For each fixed
and all large
,
the interval
contains more than
primes. Another heuristic for the prime number theorem: If
“decreases steadily” to
,
then
,
as
. |
| September 18 |
|
| September 16 |
Analysis of the size of
.
Prime factorization of
.
Deduction that
.
Reformulation in terms of
,
where
.
|
| September 14 |
One reason you might guess that
,
as
.
-adic valuations,
-adic absolute values, and the product formula.
Euclid's proof from the point of view of the product formula.
|
| September 11 |
Completion of discussion of
. Pseudoprimes and Carmichael numbers.
|
September 9 |
Some correspondence between Goldbach and Euler. If
is nonconstant, then
is composite for some positive integer
.
A polynomial in 26 variables whose positive range is precisely the set of prime numbers.
Bunyakovsky's conjecture. Iwaniec's theorem on
.
Start of discussion of primes of the form
.
|
| September 4 |
Proof there are infinitely many primes through understanding the maximal ideals of
.
Washington's proof via Dedekind domains and commutative algebra. Goldbach's theorem that there are no (one-variable) polynomials that only represent primes.
|
| September 2 |
The estimate
,
via counting lattice points. Generalizing to
and the deduction that there are infinitely many primes. Discussion of maximal
ideals in
.
|
| August 31 |
More on formal Dirichlet series. Möbius inversion as inverting
.
Why we define
the way we do. |
| August 28 |
The Möbius function. Detecting 1 with Möbius and the Möbius inversion formula. An uncertainty principle for the Möbius function. Start of discussion of formal Dirichlet series.
|
| August 26 |
Infinitely many primes from
.
A positive proportion of numbers are squarefree.
A proof of Erdős that
for all positive integers
.
Erdős's proof that
diverges.
|
| August 24 |
Proof that
.
Upper bounds on
(first steps). Euler's solution of the Basel problem.
Hacks's proof that there are infinitely many primes.
|
| August 21 |
Arithmetic functions. Multiplicative functions, and examples. Euler's factorization theorem. Application: There are infinitely many primes. In fact, the sum of reciprocals of the primes diverges. Euler's claim that .
|
| August 19 |
Furstenberg's proof. Coprime integer sequences. Goldbach's proof. Prime divisors of Fermat numbers. Infinitude of primes congruent to 1 mod powers of 2. A folklore proof with Mersenne numbers. |
| August 17 |
Go over syllabus. Euclid's proof. Stieltjes's version. A lesser-known proof of Euclid's lemma. Braun's proof. |