On a Conjecture of Conrad, Diamond, and Taylor

Modularity of some potentially Barsotti-Tate Galois representations

We prove a portion of a conjecture of B. Conrad, F. Diamond, and R. Taylor, yielding some new cases of the Fontaine-Mazur conjectures, specifically, the modularity of certain potentially Barsotti-Tate Galois representations. The proof follows the template of Wiles, Taylor-Wiles, and Breuil-Conrad-Diamond-Taylor, and relies on a detailed study of the descent, across tamely ramified extensions, of finite flat group schemes over the integers of a local field. This makes crucial use of the filtered ϕ_1-modules of C. Breuil.

Explicit Serre weights for two-dimensional Galois representations

We prove the explicit version of the Buzzard--Diamond--Jarvis conjecture formulated by Diamond--Dembélé--Roberts. More precisely, we prove that it is equivalent to the original Buzzard--Diamond--Jarvis conjecture, which was proved for odd primes (under a mild Taylor--Wiles hypothesis) in earlier work of the third author and coauthors.

通过拼接方法证明全实域上志村曲线的伊原引理

Ihara's lemma for Shimura curves over totally real fields via patching

本文利用拼接方法，在大像假设下证明了全实域上志村曲线模 $l$ 上同调的伊原引理，避免了 Diamond-Taylor 方法中对 $l$ 的额外限制。

Diamond diagrams and multivariable $(φ,\mathcal{O}_K^{\times})$-modules

Let $p$ be a prime number and $K$ a finite unramified extension of $\mathbb{Q}_p$. Let $π$ be an admissible smooth mod $p$ representation of $\mathrm{GL}_2(K)$ occurring in some Hecke eigenspaces of the mod $p$ cohomology and $\overline{r}$ be its underlying global two-dimensional Galois representation. When $\overline{r}$ satisfies some Taylor-Wiles hypotheses and is sufficiently generic at $p$, we compute explicitly certain constants appearing in the diagram associated to $π$, generalizing the results of Dotto-Le. As a result, we prove that the associated étale $(φ,\mathcal{O}_K^{\times})$-m…

Modularity lifting theorems for Galois representations of unitary type

We prove modularity lifting theorems for l-adic Galois representations of any dimension satisfying a unitary type condition and a Fontaine-Laffaille type condition at l. This extends the results of Clozel, Harris and Taylor, and the subsequent work by Taylor. The proof uses the Taylor-Wiles method, as improved by Diamond, Fujiwara, Kisin and Taylor, applied to Hecke algebras of unitary groups, and results of Labesse on stable base change and descent from unitary groups to GL_n.

Proof of de Smit's conjecture: a freeness criterion

Let $A\to B$ be a morphism of Artin local rings with the same embedding dimension. We prove that any $A$-flat $B$-module is $B$-flat. This freeness criterion was conjectured by de Smit in 1997 and improves Diamond's Theorem 2.1 from his 1997 paper "The Taylor-Wiles construction and multiplicity one". We also prove that if there is a nonzero $A$-flat $B$-module, then $A\to B$ is flat and is a relative complete intersection (i.e. $B/\mathfrak{m}_AB$ is a complete intersection). Then we explain how this result allows to simplify Wiles's proof of Fermat's Last Theorem: we do not need the so-called…