Events & Seminars

2016 Apr 21

Number Theory: Benjamin Matschke (University of Bordeaux) "A database of rational elliptic curves with given bad reduction"

2:00pm to 3:15pm

Location: 

TBA
In this talk we present a database of rational elliptic curves with
good reduction outside certain finite sets of primes, including the
set {2, 3, 5, 7, 11}, and all sets whose product is at most 1000.
In fact this is a biproduct of a larger project, in which we construct
practical algorithms to solve S-unit, Mordell, cubic Thue, cubic
Thue--Mahler, as well as generalized Ramanujan--Nagell equations, and
to compute S-integral points on rational elliptic curves with given
Mordell--Weil basis.
2017 Nov 06

NT&AG: Walter Gubler (University of Regensburg), "The non-archimedean Monge-Ampère problem"

2:00pm to 3:00pm

Location: 

Ros 70
Abstract: Calabi conjectured that the complex Monge-Ampère equation on compact Kaehler manifolds has a unique solution. This was solved by Yau in 1978. In this talk, we present a non-archimedean version on projective Berkovich spaces. In joint work with Burgos, Jell, Künnemann and Martin, we improve a result of Boucksom, Favre and Jonsson in the equicharacteristic 0 case. We give also a result in positive equicharacteristic using test ideals.
2016 Dec 19

NT&AG: Edva Roditty-Gershon (University of Bristol), "Arithmetic statistics in function fields"

2:00pm to 3:00pm

Location: 

Manchester Building, Faculty Lounge
Abstract: In the talk I will discuss classical problems concerning the distribution
of square-full numbers and their analogues over function fields. The
results described are in the context of the ring Fq[T ] of polynomials
over a finite field Fq of q elements, in the limit q → ∞.
I will also present some recent generalization of these kind of
classical problems.
‏האירוע הזה כולל שיחת וידאו ב-Google Hangouts.
2016 Mar 17

Number theory

Repeats every week every Thursday until Wed Mar 16 2016 .
12:00pm to 1:15pm

Location: 

Ross Building, room 70, Jerusalem, Israel
2017 Jun 05

NT&AG: Simon Marshall (University of Wisconsin), "Endoscopy and cohomology growth on U(n,1) Shimura varieties"

2:00pm to 3:00pm

Location: 

Ros 70
Using the endoscopic classification
of automorphic forms for unitary groups,
I will prove conjecturally sharp upper
bounds for the growth of Betti numbers
in congruence towers of complex
hyperbolic manifolds. This is
joint work with Sug Woo Shin.
‏האירוע הזה כולל שיחת וידאו ב-Google Hangouts.
הצטרף: https://plus.google.com/hangouts/_/calendar/ODdkc2JxNmlmbjNhZ2U0ODVvb3E3...
2018 Jan 08

NT&AG: Hershy Kisilevsky (Concordia University), "Special Values of twists of Modular/Elliptic L-Functions"

2:00pm to 3:00pm

Location: 

Room 70A, Ross Building, Jerusalem, Israel
Let L(E/Q, s) be the L-function of an elliptic curve E defined over the rational field Q. We examine the central value L(E, 1, χ) of twists of L(E/Q, s) by Dirichlet characters χ. We discuss the vanishing and non-vanishing frequencies of these values as χ ranges over characters of fixed order greater than 2. We also examine thee square-free part of the algebraic part of L(E/F, 1) for abelian fields F/Q when these values are non-zero.
2016 Feb 15

Number theory: Andrey Levin (Moscow) "Kronecker double series at CM points and dilogarithm"

2:00pm to 3:00pm

Location: 

Ross building, 70A
This talk is in natural in the context of the Zagier conjecture.
We express values of the Kronecker double series at CM points in
terms of values some version (Bloch-Wigner) of dilogarithm in algebraic
numbers. As zeta-function of the Hilbert class field of quadratic field can
be expressed as combination of the Kronecker double series at CM points
my result gives explicit form of the Zagier conjecture.
My technique is rather elementary and the proof is based on the introduction
some new function (elliptic (1,1)-logarithm) and comparisons with it.
2017 May 29

NT&AG: Nicolas Templier (Cornell University), "Mirror symmetry for minuscule flag varieties"

2:00pm to 3:00pm

Location: 

Ros70A
We prove cases of Rietsch mirror conjecture that the quantum
connection for projective homogeneous varieties is isomorphic to the
pushforward D-module attached to Berenstein-Kazhdan geometric crystals.
The idea is to recognize the quantum connection as Galois and the
geometric crystal as automorphic. In particular we link the purity of
Berenstein-Kazhdan crystals to the Ramanujan property of certain Hecke
eigensheaves.
The isomorphism of D-modules comes from global rigidity results where a
2016 Nov 21

NT&AG: Damaris Schindler (Utrecht University), "Systems of quadratic forms"

2:00pm to 3:00pm

Location: 

Ros Building, 70A
In this talk we discuss some aspects concerning the arithmetic of
systems of quadratic forms. This includes a result on the frequency of
counterexamples to the Hasse principle for del Pezzo surfaces of degree
four (joint work with J. Jahnel), and a result on the representability of
integers by systems of three quadratic forms (joint work with L. B. Pierce
and M. M. Wood).
2018 Jan 01

NT&AG: Efrat Bank (University of Michigan), "Correlation between primes in short intervals on curves over finite fields"

2:00pm to 3:00pm

Location: 

Room 70A, Ross Building, Jerusalem, Israel
In this talk, I present an analogue of the Hardy-Littlewood conjecture on the asymptotic distribution of prime constellations in the setting of short intervals in function fields of smooth projective curves over finite fields.
I will discuss the definition of a "short interval" on a curve as an additive translation of the space of global sections of a sufficiently positive divisor E by a suitable rational function f, and show how this definition generalizes the definition of a short interval in the polynomial
setting.
2017 Feb 27

NT&AG: Eyal Goren (McGill University), "p-adic dynamics of Hecke operators"

3:00pm to 4:00pm

Location: 

Ross 70A
Abstract:
Motivated by understanding the action of Hecke operators on special sub-varieties of Shimura varieties, we consider the simplest possible case: the action of Hecke operators on the j-line, namely on the moduli space of elliptic curves, and in particular the action on singular moduli. Our interest is in this action considered in the p-adic topology. The emerging picture is surprisingly rich and the answers involve Serre-Tate coordinates, the Gross-Hopkins period map and finally involves random walks on GL_n.
This is joint work with Payman Kassaei (King's College).
2016 Feb 22

Combinatorics

Repeats every week every Monday until Sun Feb 28 2016 .
10:30am to 12:30pm

Location: 

B221 Rothberg (CS and Engineering building)
Speaker: Asaf Nachmias (TAU)
Title: The connectivity of the uniform spanning forest on planar graphs
Abstract:
The free uniform spanning forest (FUSF) of an infinite connected graph G is obtained as the weak limit uniformly chosen spanning trees of finite subgraphs of G. It is easy to see that the FUSF is supported on spanning graphs of G with no cycles, but it need not be connected. Indeed, a classical result of Pemantle ('91) asserts that when G=Z^d, the FUSF is almost surely a connected tree if and only if d=1,2,3,4.

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