Archive from 2010 to 2015

Current seminar web page

Fall 2015

7 September 2015
16:00-17:00 Oihana Garaialde (University of the Basque Country)
Cohomology of p-groups of maximal class
14 September 2015
no seminar
21 September 2015
2 talks
14:30-15:30 René Schoof (Università di Roma “Tor Vergata”)
The discrete logarithm problem
16:00-17:00 Alberto Bellardini (Leuven)
Picard functor and logarithmic geometry
5 October 2015
16:00-17:00 Daniel Tubbenhauer (Bonn)
Web calculi in representation theory
19 October 2015
no seminar
26 October 2015
16:00-17:00 Hang Xue (MPIM Bonn)
Gan--Gross--Prasad conjecture for unitary groups

2 November 2015
no seminar
9 November 2015
no seminar
16 November 2015
16:00-17:00 Sho Tanimoto (Copenhagen)
Towards a refinement of Manin's conjecture

23 November 2015
16:00-17:00 Léo Ducas (CWI Amsterdam)
Recovering Short Generators of Principal Ideals in Cyclotomic Rings

30 November 2015
16:00-17:00 Roland van der Veen (Leiden)
Algebraic curves from knots

7 December 2015
16:00-17:00 TBA

Spring 2015

9 February 2015
16:00-17:00 Arno Kret
The Arthur-Selberg trace formula and the geometry of Shimura varieties modulo p

16 February 2015
16:00-17:00 David Holmes (Leiden)
Families of elliptic curves over bases of various dimensions

5 March 2015
Thursday, room 407
10:00 - 10:45
Yuri Bilu (Bordeaux)
Special points on straight lines and hyperbolas
11:00 - 11:45 Pascal Autissier (Bordeaux)
Abelian varieties and the Minkowski-Hlawka theorem
13:45 Academiegebouw, Rapenburg Leiden, PhD defense of Junjiang Liu
p-adic decomposable form inequalities
9 March 2015
16:00-17:00 José Ignacio Burgos Gil (Madrid)
Equidistribution of small points on toric varieties

23 March 2015
16:00-17:00 Christopher Daw (IHES)
Heights of pre-special points of Shimura varieties

30 March 2015
16:00-17:00 Julian Lyczak (Leiden)
Nodal curves on surfaces, an application of algebraic cobordism

9 April 2015
Thursday, room B3
different day, time and place
14:45-15:45 Efthymios Sofos (MPIM Bonn)
Counting rational points on smooth cubic surfaces

13 April 2015
16:00-17:00 Barinder Banwait (Essen)
Tetrahedral Elliptic Curves and the local-global principle for isogenies

20 April 2015
16:00-17:00 Arne Smeets
On a monodromy trace formula for varieties over discretely valued fields

29 April 2015
17:00-18:00 Gabriel Zalamansky
Ramification theory for inseparable coverings
30 April 2015
room 401
Jeanine van Order (MPIM Bonn)
Dirichlet twists of GL(n)-automorphic L-functions

4 May 2015
16:00-17:00 Daniele Turchetti
Lifting Galois covers of curves: a non-Archimedean analytic approach

11 May 2015
16:00-17:00 Manolis Tzortzakis
Dessins d' enfants

26 May 2015
2 talks, early start
room 312
Michiel Kosters
The last fall degree and an application to HFE

room 312
Everett Howe
The number of genus-2 curves with nonsimple Jacobians

1 June 2015 16:00-17:00 Shanta Laishram (New Delhi)
Fibonacci numbers of the form xa ± xb ± 1
8 June 2015
16:00-17:00 Lars Kuehne (MPIM Bonn)
Effective and uniform results of André-Oort type

15 June 2015
2 talks
15:15-16:00 Frauke Bleher (Iowa)
Ordering modules using orbit closures

16:15-17:00 Ted Chinburg (Pennsylvania)
Chern classes in Iwasawa theory

16 June 2015
PhD defence + 3 talks
Rapenburg 73
PhD defence of Santosh Nadimpalli

Snellius 412
Santosh Nadimpalli (Orsay and Leiden)
Classification of typical representations for GL_4(F)

Snellius 412
Shaun Stevens (UEA, Norwich)
On modular representations of p-adic classical groups

Snellius 412
Guy Henniart (Orsay)
Higher ramification theory and the local Langlands correspondence for GL(n)

23 June 2015
Algant graduation talks
room 412
10:30 - 11:30 Alessandro Pezzoni
On the complexity of irrational algebraic numbers

11:30 - 12:30 Edoardo Lanari
Compatibility of homotopy colimits and homotopy pullbacks of simplicial presheaves

13:30 - 14:30 Marco Vergura
A Giraud-type theorem for model topoi
14:30 - 15:30 Stefano Nicotra
Finite dimensional pure motives
16:00 - 17:00 Stefan van der Lugt
Arakelov intersection theory applied to torsors of semi-stable elliptic curves

17:00 - 18:00 Sergio Zarabara
An étale view of Galois Cohomology

Fall 2014

15 September 2014
16:00-17:00 René Schoof (Università di Roma “Tor Vergata”)
Serre’s Uniformity Conjecture
29 September 2014
16:00-17:00 Rodolphe Richard (Universiteit Leiden)
6 October 2014
15:30 - 16:30 Elisa Lorenzo (Universiteit Leiden)
Some arithmetic properties of twists of the Klein quartic (abstract)
13 October 2014
16:00-17:00 Carlo Pagano (Universiteit Leiden)
There are no non-zero abelian varieties defined over Z with good reduction at every prime
27 October 2014
16:00-17:00 Pavel Solomatin (Universiteit Leiden)
Curves with many points over finite fields: the classfield theory approach.
3 November 2014
16:00-17:00 Andrea Ferraguti (Universität Zürich)
Q-curves, modularity and L-functions
10 November 2014
16:00-17:00 Miguel Grados (HU Berlin)
Estimates of canonical Green’s functions (abstract)
17 November 2014
16:00-17:00 Eva Martínez (FU-Berlin)
The tensor product problem in Arakelov geometry
24 November 2014
room B1
(note the time
and place)
Ziyang Gao (Universiteit Leiden)
The mixed Ax-Lindemann theorem and its applications to the Zilber-Pink conjecture
(followed by the PhD defense of the speaker at 13:45 in the city centre)
8 December 2014
16:00-17:00 Misja Steinmetz (Cambridge)
Asymptotic Behaviour of the Conjugacy Probability of the Symmetric and Alternating Groups
(last talk of the semester)

Spring 2014

Masters thesis presentations
Niels uit de Bos: Deriving general (non-additive) functors
Raymond van Bommel: Almost all hyperelliptic Jacobians have a bad semi-abelian prime
Giulio Orecchia: Torsion-free rank one sheaves on a semi-stable curve
Rosa Winter: Concurrent exceptional curves on del Pezzo surfaces of degree one
Andrea Pasquali: Representations of SL2 and GL2 in defining characteristic
Riccardo Ferrario: Galois closures for monogenic degree-4 extensions of rings
16:00-17:00 Dijana Kreso (Graz)
Rational function decomposition and Diophantine equations
16:00-17:00 Ziyang Gao (Orsay/Leiden)
The Ax-Lindemann theorem for the universal family of abelian varieties
Sn 412?
Daniel Loughran (Hannover)
Good reduction of complete intersections
17:00-18:00 Jon Gonzalez Sanchez (Bilbao)
From p-groups to pro-p groups and back
15:45-16:45 Mima Stanojkovski (Leiden)
Evolving groups and intensity
16:00-17:00 Rostislav Devyatov (Berlin-Leiden)
Equivariant infinitesimal deformations of a special class of three-dimensional T-varieties
Sn 412
Jan Bouw (Leiden)
An algorithm to compute norm residue symbols
16:00-17:00 Niels Lindner (Berlin-Leiden)
Density of quasismooth hypersurfaces in simplicial toric varieties
16:00-17:00 Giulia Battiston (Berlin-Leiden)
The monodromy of stratified bundles in positive characteristic
16:00-17:00 Owen Biesel (Leiden)
A New Definition of Discriminant Algebra
16:00-17:00 Elmar Grosse Klönne (Berlin)
A partial generalization of Colmez' functor
16:00-17:00 Dirk Basson (Leiden)
Drinfeld modular forms of higher rank
16:00-17:00 José Ignacio Burgos Gil (Madrid)
The singularities of the invariant metric of the sheaf of Jacobi forms on the universal elliptic curve.

Fall 2013

16:00-17:00 Rachel Newton (Bonn)
Computing transcendental Brauer groups of products of CM elliptic curves
Sn 312
Guillermo Mantilla (Lausanne)
Weak arithmetic equivalence of number fields
Ekaterina Amerik (Moscow, Paris)
Some remarks about the dynamical Hasse principle
16:00-17:00 Sorina Ionica (Paris)
Isogeny graphs with real multiplication
16:00-17:00 Marco Streng (Leiden)
Computing endomorphism rings of abelian varieties using class groups (joint work with Gaetan Bisson)
Sn 312
Gabor Wiese (Luxembourg)
On Galois representations and the Inverse Galois Problem
16:00-17:00 Markus Perling (Bielefeld)
Exceptional collections on (rational) surfaces
16:00-17:00 David Holmes (Leiden)
Rational points on Kummer varieties and ranks of elliptic curves
11:00-12:00 (!)
Sn B3
Martin Bright (Beirut)
Brauer groups of singular del Pezzo surfaces
16:00-17:00 Tzanko Matev (Bayreuth)
Algebraic dependencies of the multiplicative group

Spring 2013

16:00-17:00 David Holmes (Leiden)
Distribution of rational points on Kummer varieties
16:00-17:00 Owen Biesel (Princeton)
G-closures for ring extensions
7/3/2013 16:00-17:00 Cecília Salgado (Universidade Federal do Rio de Janeiro)
Unirationality of del Pezzo surfaces of degree two
14/3/2013 16:00-17:00 Alex Bartel (Warwick University)
The difference between rational representations and permutation representations of a finite group
16:00-17:00 Hendrik Lenstra (Leiden)
Lattices with symmetry, I
21/3/2013 15:45-17:30 Hendrik Lenstra (Leiden)
Lattices with symmetry, II
16:00-17:00 Jan Steffen Müller (Hamburg)
Canonical heights on Jacobians of hyperelliptic curves
28/3/2013 16:00-17:00 No seminar, but colloquium

11/4/2013 16:00-17:00 No seminar, but colloquium

18/4/2013 16:00-17:00 No seminar, but colloquium

16:00-17:00 Kloosterman lecture

Algant pre-defense (Duong Hoang Dung defends his PhD thesis on May 14)
Andrea Lucchini (Padova): Boundedly generated subgroups of finite groups
Christopher Voll (Bielefeld): Zeta functions of groups and rings
16/5/2013 16:00-17:00 Paloma Bengoechea (Collège de France)
From quadratic polynomials and continued fractions to modular forms
Sn 402
Olivier Wittenberg (ENS Paris, CNRS) On the cycle class map for zero-cycles over local fields
Jinbi Jin (Leiden): Classification of torsors over curves
David Madore (ENST Paris): Church-Turing computability of étale cohomology
Sn 402
15:00-17:15 Bhargav Bhatt (IAS Princeton)
Crystalline and de Rham cohomology 1 & 2
Sn 402
15:00-17:15 Bhargav Bhatt (IAS Princeton)
Crystalline and de Rham cohomology 3 & 4
4/7/2013 16:00-17:00 Wei Ho (Columbia)
Families of lattice-polarized K3 surfaces

Fall 2012

Lectures take place on Mondays from 16:00 to 17:00 in room Sn401, unless mentioned otherwise.

3/12/2012 Hendrik Lenstra (Leiden)
Finding idempotents and torsion units in orders
19/11/2012 Cédric Pépin (Leuven)
Perspectives on the duality for Néron models of abelian varieties
5/11/2012 Heer Zhao (Cambridge)
Degeneration of Abelian Varieties over Complete DVR
22/10/2012 Rachel Newton (Leiden)
Realising the cup-product of local Tate duality
15/10/2012 Julio Brau (Leiden)
Growth of p-Selmer groups of elliptic curves in p-extensions
8/10/2012 Fernando Rodriguez Villegas (ICTP Trieste)
Hypergeometric motives
1/10/2012 David Holmes (Leiden)
Néron-Tate heights and Arakelov theory
24/09/2012 Christophe Debry (Leuven/Leiden)
A division polynomial condition for supersingularity
17/09/2012 Alice Silverberg (UC Irvine)
A lattice algorithm of Gentry and Szydlo

Spring 2012

Lectures take place on Mondays from 16:00 to 17:00 in room Sn403, unless mentioned otherwise. The seminar is preceded by a study group on moduli of elliptic curves.

Wed 13/6/2012
16:00, Sn401
Ted Chinburg (Philadelphia)
Self dual codes, number theory and topology
21/5/2012 Federico Pellarin (St.-Etienne)
On the values of Goss' zeta function
14/5/2012 James Sellers (Penn State)
Unique Path Partitions: Characterization and Congruences
7/5/2012 Sean Howe (Leiden)
Higher genus counter-examples to the "naive" relative Manin-Mumford conjecture
23/4/2012 Niels Lubbes (Linz)
Families of circles on real surfaces
2/4/2012 Michiel Kosters (Leiden)
Determining S-units of an order in a quaternion algebra
12/3/2012 Raf Cluckers (Lille/Leuven)
Transfer principles for motivic integrals and their applications in the Langlands program
5/3/2012 Matthieu Romagny (Jussieu)
Reduction at p of coverings of curves of higher genus
27/2/2012 René Pannekoek (Leiden)
On p-adic density of rational points on K3 surfaces
13/2/2012 Alberto Gioia (Leiden)
Universal homeomorphisms and Galois theory
Wed 8/2/2012
14:00, Sn402
Alexei Skorobogatov (Imperial College)
Towards calculating the transcendental Brauer group

Fall 2011

Lectures take place on Mondays from 16:00 to 17:00 in room Sn402, unless mentioned otherwise

Tue 3/1/2012
Arno Kret (Orsay)
The basic stratum of some one-dimensional Shimura varieties
19/12/2011 Jinbi Jin (Leiden)
Point counting formulae on universal elliptic curves
Mark Watkins (Sydney)
Indefinite LLL and solving quadratic equations
Hendrik Lenstra (Leiden)
Discriminants of wild extensions II
14/11/2011 Daniel Ferrand (Rennes/Jussieu)
Norm and corestriction
7/11/2011 Peter Jossen (Orsay)
Tate-Shafarevich groups whose finiteness implies Leopoldt's conjecture
Hendrik Lenstra (Leiden)
Discriminants of wild extensions
24/10/2011 Bas Edixhoven (Leiden)
Gauss's theorem on sums of three squares via group schemes
26/9/2011 Rob Eggermont (Leiden)
Witt rings and their applications to the theorem of Brauer-Nesbitt - (abstract)
Alberto Facchini (Padova)
Semilocal categories

Spring 2011

Lectures take place on Mondays from 14:30 to 15:30 in room Sn312, unless mentioned otherwise

Tue 31/5/2011
14:30, Sn403
Hendrik Lenstra (Leiden)
Field topologies on unions of finite fields
2/5/2011 Bruno Anglès (Caen)
On the derivative of certain Artin L-functions in characteristic p
18/4/2011 Mihran Papikian (Penn State)
Elliptic sheaves and odd Jacobians
15:45, Sn401
Nils Bruin (Simon Fraser University)
On primes p with class number of Q(\sqrt{-4p}) divisible by 16
7/3/2011 Ambrus Pál (Imperial College)
Rational points and homotopy theory
16:00, Sn405
Eduardo Esteves (IMPA)
The class of stable hyperelliptic curves of genus 3

Fall 2010

Lectures take place on Wednesdays from 16:00 to 17:00 in room Sn402.

19/1/2011 Chris Peters (Grenoble)
Abelian varieties as invariants for Riemannian manifolds (2)
5/1/2011 Chris Peters (Grenoble)
Abelian varieties as invariants for Riemannian manifolds (1)
15/12/2010 Johannes Nicaise (Leuven)
Rational fixed points for finite group actions, and a question of Serre
8/12/2010 Alberto Gioia (Leiden)
Bhargava's Galois closure
1/12/2010 Joost Michielsen (Leiden)
L-functions of the projective line
24/11/2010 Julio Brau (Leiden)
Computing the image of Galois representations attached to elliptic curves
10/11/2010 Sara Arias-de-Reyna (IEM Essen)
On the torsion part of the Mordell-Weil group of abelian varieties over finitely generated fields
Andrea Siviero (Bordeaux)
On Realizable Classes
3/11/2010 Filip Najman (Leiden, Zagreb)
Mordell-Weil groups of elliptic curves over quadratic fields
13/10/2010 Lenny Taelman (Leiden)
Number of solutions modulo p^n
6/10/2010 Samuele Anni (Leiden)
Modular modular Galois representations
29/9/2010 Hendrik Lenstra (Leiden)
Division points of multiplicative groups