## 2011

### Intercity number theory seminar

25 February, Utrecht. The lectures are in room BBL205 on the second floor of the Buys Ballot building. There will be tea and coffee at 15:20- 11:30–12:20
- Tom Ward, Counting fixed points of group automorphism
In December 2020, Peter Scholze posed a challenge to formally verify the main theorem on liquid ℝ-vector spaces, which is part of his joint work with Dustin Clausen on condensed mathematics. I took up this challenge with a team of mathematicians to verify the theorem in the Lean proof assistant. Half a year later, we reached a major milestone, and our expectation is that shortly we will have completed the full challenge. In this talk I will give a brief motivation for condensed/liquid mathematics, a demonstration of the Lean proof assistant, and discuss our experiences formalizing state-of-the-art research in mathematics.
- 13:30–14:20
- Soroosh Yazdani, Local Szpiro's conjecture
In December 2020, Peter Scholze posed a challenge to formally verify the main theorem on liquid ℝ-vector spaces, which is part of his joint work with Dustin Clausen on condensed mathematics. I took up this challenge with a team of mathematicians to verify the theorem in the Lean proof assistant. Half a year later, we reached a major milestone, and our expectation is that shortly we will have completed the full challenge. In this talk I will give a brief motivation for condensed/liquid mathematics, a demonstration of the Lean proof assistant, and discuss our experiences formalizing state-of-the-art research in mathematics.
- 14:30–15:20
- Sander Dahmen, Klein forms and the generalized superelliptic equation
In December 2020, Peter Scholze posed a challenge to formally verify the main theorem on liquid ℝ-vector spaces, which is part of his joint work with Dustin Clausen on condensed mathematics. I took up this challenge with a team of mathematicians to verify the theorem in the Lean proof assistant. Half a year later, we reached a major milestone, and our expectation is that shortly we will have completed the full challenge. In this talk I will give a brief motivation for condensed/liquid mathematics, a demonstration of the Lean proof assistant, and discuss our experiences formalizing state-of-the-art research in mathematics.
- 15:40–16:30
- Jonathan Reynolds, Modular methods for perfect powers in elliptic divisibility sequences

### Intercity number theory seminar

11 March, VU Amsterdam. room M-623 (W&N building)- 11:15–12:15
- James Lewis, An Archimedean height pairing on the equivalence relation defining Bloch's higher Chow groups
- 13:15–15:15
- Jean-Louis Colliot-Thelene, Lectures on the Hasse principle, I
- 15:30–16:30
- Ronald van Luijk, Computability of Picard numbers

### Intercity number theory seminar

25 March, Leiden. room 412- 11:15–12:15
- Damiano Testa, The surface of cuboids and Siegel modular threefolds
- 13:15–15:15
- Jean-Louis Colliot-Thelene, Lectures on the Hasse principle, II
- 15:30–16:30
- Martin Bright, Some computational aspects of the Brauer-Manin obstruction

### Intercity number theory seminar

8 April, Leiden. room 412- 11:45–12:45
- Christine Berkesch, The rank of a hypergeometric system
- 13:45–15:45
- Jean-Louis Colliot-Thelene, Lectures on the Hasse principle, III
- 16:00–17:00
- Andrei Teleman, Holomorphic bundles and holomorphic curves on class VII surfaces. The classification problem for class VII surfaces.

### Intercity number theory seminar

29 April, Groningen. room 105 Bernoulliborg- 11:45–12:45
- Karl Rökaeus Amsterdam, Global function fields with many rational places
- 13:30–15:45
- Jean-Louis Colliot-Thelene, Lectures on the Hasse principle, IV
- 16:00–17:00
- Remke Kloosterman, Calculating the Mordell-Weil group for a class of elliptic threefolds

### Intercity Number Theory Seminar

13 May, Utrecht. room 211, Minnaert building- 11:30–12:20
- Janne Kool Utrecht, Measure theoretic rigidity for Mumford curves
- 13:30–14:20
- Tom Ward, The work of Einsiedler, Katok and Lindenstrauss on the Littlewood conjecture
- 14:40–15:30
- Tanja Eisner, Arithmetic progressions via ergodic theory
- 15:40–16:30
- Karl Petersen, Some combinatorial and number-theoretic questions related to certain adic dynamical systems

### Intercity Number Theory Seminar

10 June, Gent. Lecture room "Emmy Noether", campus Sterre S25, Galglaan 2, Gent. This is a 10 minute walk or 5 minute tram ride (tram 21 or 22) from train station "Gent Sint-Pieters", see directions and maps.- 13:30–14:50
- Gunther Cornelissen, Reconstructing number fields using quantum statistical mechanics
- 15:00–15:50
- Bart de Smit, Characterizing number fields with abelian L-functions
- 16:10–17:30
- Frits Beukers, A-hypergeometric functions

### Intercity Number Theory Seminar

16 September, Leiden. Room 403- 13:30–14:30
- Alberto Facchini, Krull-Schmidt Theorem: the case two
- 14:45–15:45
- Antonella Perucca, Radical characterizations of elliptic curves
- 16:00–17:00
- René Schoof, Integral points on a modular curve of level 11

### Intercity Number Theory Seminar

30 September, Delft. Snijderszaal (zaal LB 01.010, 1e verdieping EWI gebouw)- 13:00–14:00
- Valérie Berthé, Adic constructions for fundamental domains for Kronecker sequences
- 14:10–14:55
- Milan Lopuhaä Leiden, Field topologies on countable fields
- 14:55–15:40
- Henk Don, Polygons in billiard orbits

### Intercity Number Theory Seminar

28 October, Leuven. Building 200C, 01.0010 (first floor); see this campus map [PDF] for directions.- 13:30–14:30
- Wouter Castryck, Frobenius statistics for varying curves over fixed finite fields
- 14:45–15:45
- Gabriele Dalla Torre,
*L*-function-preserving isomorphisms of groups of quadratic characters - 16:15–17:15
- Peter Jossen, The unipotent part of the Mumford-Tate conjecture

### RISC/Intercity Number Theory Seminar

11 November, CWI Amsterdam. Last minute room change: the lectures are in room *L120* (first floor, new wing). See also the RISC page.- 11:45–12:30
- Ariel Gabizon Israel Institute of Technology - Technion / CWI, Extractors : Background, Applications and Recent Constructions
- 14:00–14:45
- Gil Cohen Weizmann Institute of Science, Non-Malleable Extractors with Short Seeds and Applications to Privacy Amplification
- 15:00–15:45
- Stefan Dziembowski Rome, Leakage-Resilient Cryptography From the Inner-Product Extractor
- 16:00–16:45
- Christian Schaffner UVA/CWI, Randomness extraction and expansion in the quantum world

### Intercity Number Theory Seminar

9 December, Leiden. Room 174- 13:30–14:30
- Pascal Autissier, On the non-density of integral points
- 14:45–15:45
- Fabrizio Andreatta, On
*p*-adic families of elliptic overconvergent modular forms - 16:00–17:00
- Jan-Hendrik Evertse, Multiply monogenic orders

### Intercity Number Theory Seminar

16 December, Groningen. The first two lectures will be in the Heymanszaal in the Academiegebouw, Broerstraat 5, in Groningen. The PhD defense will be in the Aula in the same building.- 11:00–12:00
- Matthias Schuett, Arithmetic of quintic surfaces
- 13:00–14:00
- Tetsuji Shioda, Cubic surfaces via Mordell-Weil lattices, re-revisited
- 14:30–15:30
- Bas Heijne, PhD defense: Elliptic Delsarte Surfaces.