Seminars Sorted by Series

Proving the equidistribution of roots of quadratic congruences, with strong estimates on the Weyl sums, is one of the most spectacular applications of the spectral theory of automorphic forms to arithmetic. See for example Duke, Friedlander and...

Hilbert’s 12th problem is to provide explicit analytic formulae for elements generating the maximal abelian extension of a given number field. In this talk I will describe an approach to Hilbert’s 12th that involves proving exact p-adic formulae for...

Honda-Tate theory says that every abelian variety mod p is isogenous to the reduction of a CM abelian variety.We will discuss the analogous statement for isogeny classes on Shimura varieties, and explain what is conjectured and what is known.

Affine Deligne-Lusztig varieties (ADLV) naturally arise in the study of Shimura varieties and Rapoport-Zink spaces; their irreducible components give rise to interesting algebraic cycles on the special fiber of Shimura varieties. We prove a...

Saito--Tunnell theorem is a local version of Waldspurger's formula, relating the existence of E^\times invariant linear forms on representation of GL_2 to local root numbers. I present a generalization of this which relates the existence of GL_n(E)...

I will begin with a gentle introduction to hyperrings and hyperfields (originally introduced by Krasner for number-theoretic reasons), and then discuss a far-reaching generalization, Oliver Lorscheid’s theory of ordered blueprints. Two key examples...

It is known that the modular curve has good reduction at $p$ if the level structure is prime to $p$. If the level structure is of $\Gamma_0(p)$-type, then the modular curve has semi-stable reduction. For general Shimura varieties, one may ask for...

We study the function field analogue of a classical problem in analytic number theory on the sums of the generalized divisor function in short intervals, in the limit as the degrees of the polynomials go to infinity. As a corollary, we calculate...

I will present a computation of the integral p-adic etale cohomology of the Drinfeld half-space. Via integral p-adic Hodge Theory of Bhatt-Morrow-Scholze this reduces to a computation of the integral de Rham cohomology and this can be done...

The study of eigenvarieties began with Coleman and Mazur, who constructed the first eigencurve, a rigid analytic space parametrizing $p$-adic modular Hecke eigenforms. Since then various authors have constructed eigenvarieties for automorphic forms...

Over one-dimensional bases, Gabber and Beilinson proved theorems on the commutation of the nearby cycle functor and the vanishing cycle functor with duality. In this talk, I will explain a way to unify the two theorems, confirming a prediction of...

In 1973, Serre observed that the Hecke eigenvalues of Eisenstein series can be p-adically interpolated. In other words, Eisenstein series can be viewed as specializations of a p-adic family parametrized by the weight. The notion of p-adic variations...

This talk is concerned with the radius of convergence of p-adic families of modular forms --- q-series over a p-adic disc whose specialization to certain integer points is the q-expansion of a classical Hecke eigenform of level p. Numerical...

I will explain a new proof of the geometric stabilization theorem for Hitchin fibers, a key ingredient in Ngô's proof of the fundamental lemma. Our approach relies on ideas of Denef-Loeser and Batyrev on p-adic integration and Langlands duality for...

In 1987, Barry Mazur and John Tate formulated refined conjectures of the "Birch and Swinnerton-Dyer type", and one of these conjectures was essentially proved in the prime conductor case by Ehud de Shalit in 1995. One of the main objects in de...

Wiles's proof of the modularity of semistable elliptic curves over the rationals uses the Langlands-Tunnell theorem as a starting point, implying that the mod 3 Galois representation attached to the elliptic curve arises from a modular form of...

The point of this talk is to give three examples of derived structures influencing representations that have connections with number theory. These structures arise from the differential graded algebra of group cochains valued in the endomorphism...

Extending on the work of Kudla-Millson and Yuan-Zhang-Zhang, together with Yott we are constructing special divisors for a specific GSpin Shimura variety. We further construct a generating series that has as coefficients the cohomology classes...

The thesis of Akshay Venkatesh obtains a Beyond Endoscopy'' proof of stable functorial transfer from tori to ${\rm SL}(2)$, by means of the Kuznetsov formula. In this talk, I will show that there is a local statement that underlies this work; namely...

Number fields with the same Dedekind zeta function are said to be arithmetically equivalent. Such number fields necessarily have the same degree, discriminant, signature, Galois closure, and isomorphic unit groups, but may have different regulators...

The theory of complex multiplication describes finite abelian extensions of imaginary quadratic number fields using singular moduli, which are special values of modular functions at CM points. I will describe joint work with Henri Darmon in the...

The Sato-Tate group of an abelian variety A of dimension g defined over a number field is a compact real Lie subgroup of the unitary simplectic group of degree 2g that conjecturally governs the limiting distribution of the normalized Frobenius...

On an elliptic curve $y^2=x^3+ax+b$, the points with coordinates $(x,y)$ in a given number field form a finitely generated abelian group. One natural question is how the rank of this group changes when changing the number field. For the simplest...

In 1927 Polya proved that the Riemann Hypothesis is equivalent to the hyperbolicity of Jensen polynomials for Riemann’s Xi-function. This hyperbolicity had only been proved for degrees d=1,2,3. We prove the hyperbolicity of all (but possibly...

The singularities in the reduction modulo $p$ of the modular curve $Y_0(p)$ are visualized by the famous picture of two curves meeting transversally at the supersingular points. It is a fundamental question to understand the singularities which...

The classical Hasse-Herbrand function is an important object in ramification theory, related to higher ramification groups. In this talk, I will discuss generalizations of the Hasse-Herbrand function and go over some of their properties. These...

We parametrise elements in the full Hecke algebra in a way such that the parametrisation represents a generic automorphic form. By convolving, we then arrive at pre-trace formulas which are modular in three variables. From here, various identities...

Bhargava showed that 100% of quintic fields have non-solvable Galois closure. For this reason, the arithmetic of elliptic curves over such fields is beyond the reach of methods based on Heegner points. In this talk we will report on a joint work in...

In their seminal work from the 80’s, Lubotzky, Phillips and Sarnak gave explicit constructions of topological generators for PU(2) with optimal covering properties. In this talk I will describe some recent works that extend the construction of LPS...

The stacky approach was originated by Bhatt and Lurie. (But the possible mistakes in my talk are mine.)

Let X be a scheme over F_p. Many years ago Grothendieck and Berthelot defined the notion of crystal on X; moreover, they defined the notion of...

This talk is about qualitative properties of the underlying scheme of Rapoport-Zink formal moduli spaces of p-divisible groups, resp. Shtukas. We single out those cases when the dimension of this underlying scheme is zero, resp. those where the...

Let G be a reductive group. Following Gross, and generalizing Serre's classical notion in the two-dimensional case, I will define what it means for a G-valued representation of the Galois group of a (totallyreal) number field to be odd. This notion...

Some 25 years ago, as announced at a previous version of this seminar, Vaughan and the speaker obtained asymptotic upper and lower bounds for the number of non-trivial integral points on the Segre cubic x31+...+x36=x1+...+x6=0x_1^3+...+x_6^3=x_1+...

We will discuss the problem of constructing and characterizing uniquely, integral models of Shimura varieties over some primes where non-smooth reduction is expected.

We discuss some recent results on singularity properties of word maps and Lie algebra word maps on semisimple algebraic groups and semisimple Lie algebras, generalizing a work of Aizenbud-Avni done in the case of the commutator map. These...

The Farey subdivision of the real line describes the action of PSL(2,Z) and gives a continued fraction algorithm approximating real numbers by rational numbers. Asmus Schmidt defined an analogue for the complex plane, depending on a choice of...

In a recent work, Matomäki, Radziwill and Tao showed that the Möbius function is discorrelated with linear exponential phases on almost all intervals of length $X^{\varepsilon}$. I will discuss joint work where we generalize this result to...

This is an update on the talk I gave about 10 years ago on this seminar. The arithmetic Gan-Gross-Prasad (AGGP) conjecture, a high dimensional generalization of the Gross–Zagier theorem, relates the height pairing of arithmetic diagonal cycles on...

The Grothendieck group of varieties over a field k is the quotient of the free abelian group of isomorphism classes of varieties over k by the so-called cut-and-paste relations. It moreover has a ring structure coming from the product of varieties...

We will discuss how to study the cubic moment of any family of automorphic L-functions on PGL(2) using regularized diagonal periods of Eisenstein series, following a strategy suggested by Michel--Venkatesh. Applications include generalizations to...

In this talk, I formulate and prove a new Rubin-type Iwasawa main conjecture for imaginary quadratic fields in which p is inert or ramified, as well as a Perrin-Riou type Heegner point main conjecture for certain supersingular CM elliptic curves...

We present some work in progress, on moduli spaces of Drinfeld shtukas. These spaces are the function field analogous to Shimura varieties. In fact they are more versatile; there are r-legged versions for any r. Tate's conjecture predicts some...

In this talk, we will introduce a new technique of isolating the cuspidal part, or more general cuspidal components, from the $L^2$ spectrum on the spectral side of the trace formula. As an application, we prove the global Gan-Gross-Prasad and...

Every smooth proper algebraic variety over a p-adic field is expected to have semistable model after passing to a finite extension. This conjecture is open in general, but its analogue for Galois representations, the p-adic monodromy theorem, is...

I will discuss how the use of the p-adic Langlands correspondence for GL_2(Q_p) allows to study Eisenstein congruences of various weight, level and slopes in order to construct Euler systems. I will discuss the GL(2)-case with some details and give...

**Please note: All in-person IAS seminars have been cancelled. Seminar will be livestreamed. Please follow link: https://youtu.be/vZz1SFWHiog

Recently, Cai, Friedberg, Ginzburg and Kaplan generalized the doubling method of Piatetski-Shapiro and...

In his work on modularity theorems, Wiles proved a numerical criterion for a map of rings R->T to be an isomorphism of complete intersections. In addition to proving modularity theorems, this numerical criterion also implies a connection between the...

Let G be a real semi-simple Lie group with an irreducible unitary representation \pi. The non-temperedness of \pi is measured by the parameter p(\pi) which is defined as the infimum of p\geq 2 such that \pi has matrix coefficients in L^p(G). Sarnak...