Seminars Sorted by Series

For GL(2) over Q_p, the p-adic Langlands correspondence is available in its full glory, and has had astounding applications to Fontaine-Mazur, for instance. In higher rank, not much is known. Breuil and Schneider put forward a conjecture, which is a...

We'll prove a converse theorem for forms forms on SL_2. While the theorem is easy to prove once it has been formulated, the number-theoretic considerations leading to its formulation nevertheless pose some interesting and apparently unsolved...

Recently Nicolas and Serre have determined the structure of the Hecke algebra acting on modular forms of level 1 modulo 2, and Serre has conjectured the existence of a universal Galois representation over this algebra. I'll explain the proof of this...

In his work of the early 1980s, Shimura observed that expressions of special values of automorphic L-functions in terms of period invariants could be used to obtain relations among the latter. This observation has since been applied in numerous...

The classical Kuga-Satake construction, over the complex numbers, uses Hodge theory to attach to each polarized K3 surface an abelian variety in a natural way. Deligne and Andre extended this to fields of characteristic zero, and their results can...

To any essentially self-dual, regular algebraic (ie cohomological) automorphic representation of GL(n) over a CM field one knows how to associate a compatible system of l-adic representations. These l-adic representations occur (perhaps slightly...

For an abelian surface A over a number field k, we study the limiting distribution of the normalized Euler factors of the L-function of A. Under the generalized Sato-Tate conjecture, this is equal to the distribution of characteristic polynomials of...

Monodromy groups arise naturally in algebraic geometry and in differential equations, and often preserve an integral lattice. It is of interest to know whether the monodromy groups are arithmetic or thin. In this talk we review the Deligne-Mostow...

We consider Galois cohomology groups over function fields F of curves that are defined over a complete discretely valued field. Motivated by work of Kato and others for n=3, we show that local-global principles hold for H^n(F, Z/mZ(n-1)) for all n>1...

Abstract: Associated to an abelian variety A/K is a Galois representation which describes the action of the absolute Galois group of K on the torsion points of A. In this talk, we shall describe how large the image of this representation can be (in...

Application of Plancherel's theorem to integral kernels approximating compact period functionals yields estimates on (global) automorphic Levi-Sobolev norms of the functionals. The utility of this viewpoint can be illustrated in reconsideration of...

Let $X$ be a locally symmetric variety, $\bar{X}$ its Baily-Borel compactification, $\bar{X}^{rbs}$ its reductive Borel-Serre compactification and $p:\bar{X}^{rbs} \to \bar{X}$ the canonical map. We prove that the derived direct image sheaf $Rp_*...

Following Jacquet, Lapid and Rogawski, we define a regularized period of an automorphic form on GL(n+1) x GL(n) along the diagonal subgroup GL(n) and express it in terms of the Rankin-Selberg integral of Jacquet, Piatetski-Shapiro and Shalika. This...

I will report on the construction of p-integral models of various algebraic compactifications of PEL-type Shimura varieties and Kuga families, allowing ramification (including deep levels) at p, with good behaviors over the loci where certain...

The trace formula has been the most powerful and mainstream tool in automorphic forms for proving instances of Langlands functoriality, including character relations. Its generalization, the relative trace formula, has also been used to prove...

In this talk, I will report on an on-going joint project with David Helm and Yichao Tian. Let p be a prime unramified in a totally real field F. The Goren-Oort strata are defined by the vanishing locus of the partial Hasse-invariants; it is an...

A few years ago Ichino-Ikeda formulated a quantitative version of the Gross-Prasad conjecture, modeled after the classical work of Waldspurger. This is a powerful local-to-global principle which is very suitable for analytic and arithmetic...

Let x_1, x_2,... be a sequence of n-tuples of roots of unity and suppose X is a subvariety of the algebraic torus. For a prime number p , Tate and Voloch proved that if the p-adic distance between x_k and X tends to 0 then all but finitely many...

The theorem of the title is that if the L-function L(E,s) of an elliptic curve E over the rationals vanishes to order r=0 or 1 at s=1 then the rank of the group of rational rational points of E equals r and the Tate-Shafarevich group of E is finite...

We will discuss some new automorphy lifting theorems for residually reducible Galois representations, and their application to proving new cases of symmetric power functoriality for elliptic modular forms. This is joint work with Laurent Clozel.

I will describe work with Yingkun Li on some arithmetic properties of the Fourier coefficients of harmonic modular forms of weight one. These are Maass forms of weight one whose eigenvalue under the Laplacian is zero and that are allowed to have...

A continuous representation of a profinite group induces a continuous pseudorepresentation, where a pseudorepresentation is the data of the characteristic polynomial coefficients. We discuss the geometry of the resulting map from the moduli formal...

Let \(\chi\) be a primitive real character. We first establish a relationship between the existence of the Landau-Siegel zero of \(L(s,\chi)\) and the distribution of zeros of the Dirichlet \(L\)-function \(L(s,\psi)\), with \(\psi\) belonging to a...

Iwasawa Theory for elliptic curves/modular forms has been traditionally in better shape at ordinary primes than at supersingular ones. After sketching the ordinary theory, we will indicate what makes the supersingular case more complicated, and then...

I will explain how to use Deligne's theory of nearby cycles over general bases to prove Thom-Sebastiani type theorems.

I will begin with a brief introduction to the deformation theory of Galois representations and its role in modularity lifting. This will motivate the study of local deformation rings and more specifically flat deformation rings. I will then discuss...

Let \(E/F\) be a quadratic extension of \(p\)-adic fields. Let \(V_n\subset V_{n+1}\) be hermitian spaces of dimension \(n\) and \(n+1\) respectively. For \(\sigma\) and \(\pi\) smooth irreducible representations of \(U(V_n)\) and \(U(V_{n+1})\) set...

We prove a B-SD conjecture for elliptic curves (for the \(p^\infty\) Selmer groups with arbitrary rank) a la Mazur-Tate and Darmon in anti-cyclotomic setting, for certain primes \(p\). This is done, among other things, by proving a conjecture of...

Let \(k\) be an algebraically closed field and let \(c:C\rightarrow X\times X\) be a correspondence. Let \(\ell \) be a prime invertible in \(k\) and let \(K\in D^b_c(X, \overline {\mathbb Q}_\ell )\) be a complex. An action of \(c\) on \(K\) is by...

To any bounded family of \(\mathbb F_\ell\)-linear representations of the etale fundamental of a curve \(X\) one can associate families of abstract modular curves which, in this setting, generalize the `usual' modular curves with level \(\ell\)...

The \(p\)-adic local Langlands correspondence is well understood for \(\mathrm{GL}_2(\mathbb Q_p)\), but appears much more complicated when considering \(\mathrm{GL}_n(F)\), where either \(n>2\) or \(F\) is a finite extension of \(\mathbb Q_p\). I...

Let \(R={\cal O}_{{\bf C},0}\) be the ring of power series convergent in a neighborhood of zero in the complex plane. Every scheme \(\cal X\) of finite type over \(R\) defines a complex analytic space \({\cal X}^h\) over an open disc \(D\) of small...

It is classical that an element of the class group of a real quadratic field corresponds to a closed geodesic on the modular surface, but not every closed geodesic arises this way; we call those that do "fundamental." Given a fixed compact subset W...

The hyperbolic Ax Lindemann conjecture is a functional transcendental statement which describes the closure of "algebraic flows" on Shimura varieties. We will describe the proof of this conjecture and its consequences for the André-Oort conjecture...

An Euler system is a family of cohomology classes that satisfy some compatibility condition under the corestriction map. Kato constructed an Euler system for a modular form over the cyclotomic extensions of \(\mathbb{Q}\). I will explain a recent...

We will introduce a refinement of the `GPY sieve method' for studying small gaps between primes. This refinement will allow us to show that \(\liminf_n(p_{n+m}-p_n) \infty\) for any integer \(m\), and so there are infinitely many bounded length...

In this talk I will explain some results (joint with Vytas Paskunas) showing that certain classes of potentially crystalline representations (e.g. in the case of two-dimensional representations: crystabelline potentially Barsotti--Tate...

By studying the variation of motivic path torsors associated to a variety, we show how certain nondensity assertions in Diophantine geometry can be translated to problems concerning K-groups. Then we use some vanishing theorems to obtain concrete...

In his first letter to G. H. Hardy, Ramanujan hinted at a theory of continued fractions. He offered shocking evaluations which Hardy described as: "These formulas defeated me completely...they could only be written down by a mathematician of the...

The work of Green, Tao and Ziegler can be used to prove existence and approximation properties for rational solutions of the Diophantine equations that describe representations of a product of norm forms by a product of linear polynomials. One can...

Reeder and Yu have constructed in a uniform way certain supercuspidal representations of \(p\)-adic groups called "epipelagic representations", using invariant theory studied by Vinberg et al. In the function field case, we will realize these...

Let \[ f(t)=\sum_{N n 2N}a_nn^{-it} \] be a Dirichlet polynomial. We consider the weighted square mean value \[ I=\int_{-\infty}^{\infty}|f(t)|^2\exp\{-\Delta^{-2}(t-T)^2\}\,dt, \] where \(T\) is a large paremeter and \[ \Delta = \frac{T}{\log T}...