Royal Holloway - Number Theory Seminar

The NT-seminar takes place on Wednesday at 4pm in Munro Fox Lecture Theatre (unless stated otherwise).
Here is a campus plan.


October 2 Martin Widmer (Royal Holloway)

 

Bounds on the l-torsion part of class groups

 

Abstract: I survey some recent results on upper bounds (pointwise and on average)

of the l-torsion part of class groups of number fields.

 

 

October 9 Natasha Morrison (Cambridge)

 

Invertibility of Random Symmetric Matrices

 

Abstract:

 

 

October 16 Reynold Fregoli (Royal Holloway)

 

Bounded Exponential Sums

 

Abstract: 

 

 

October 23 Jonathan Chapman (Manchester)

 

The Ramsey number of the Brauer configuration

 

Abstract: In this talk we obtain quantitative bounds for Brauer's generalisation of van der Waerden's theorem. Brauer's theorem states that, given any positive integers k and r, there exists a positive integer N such that any colouring of the first N positive integers with r colours produces a monochromatic arithmetic progression of length k with the same colour as its common difference. By modifying the work of Gowers on Szemerédi's theorem, we show that N can be taken to be double exponential in the number of colours and quintuple exponential in the length of the progression. This talk is based on joint work with Sean Prendiville (Lancaster).

 

 

October 30 No NT-Seminar!

 

 

November 6 Kevin Buzzard (Imperial College)

 

Doing modern mathematics in Lean

 

Abstract: I will talk about the practical problems that one faces when trying to do MSc and higher level algebra and number theory using a computer theorem prover. A background in algebra / number theory will be assumed for most of the talk.

 

 



November 13 Stephanie Chan (University College London)

 

On the negative Pell equation

 

Abstract: Stevenhagen conjectured that the density of d such that the negative Pell equation x^2-dy^2=-1 is solvable over the integers is 58.1% (to the nearest tenth of a percent), in the set of positive squarefree integers having no prime factors congruent to 3 modulo 4. In joint work with Peter Koymans, Djordjo Milovic, and Carlo Pagano, we use a recent breakthrough of Smith to prove that the infimum of this density is at least 53.8%, improving previous results of Fouvry and Klüners, by studying the distribution of the 8-rank of narrow class groups of quadratic number fields.

 

 

 November 20 No NT-Seminar!

 

November 27 No NT-Seminar!

 

December 4 No NT-Seminar!

 

December 11 Joni Teräväinen (Oxford)

 

Higher order uniformity of the Möbius function

 

In recent work, Matomäki, Radziwill and Tao showed that the Möbius function is discorrelated with linear exponential phases on almost all intervals around $X$ of length $X^{\varepsilon}$. I will discuss joint work where we generalize this result to ''higher order phase functions'', so as a special case the Möbius function is shown not to correlate with polynomial phases on almost all intervals of length $X^{\varepsilon}$. As an application, we show that the number of sign patterns of length $k$ that the Liouville function takes grows superpolynomially in $k$.

 

 

 

 

 

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