Research
My research is in arithmetic geometry and number theory. I work on p-adic Hodge theory, Galois representations, and Langlands Correspondence.
Preprints
Formalization of Langlands’s Second Main Lemma for Local Epsilon Factors
Fukuhiro Ueda · 2026
A Lean 4 formalization of Langlands’s Second Main Lemma following the companion local proof. The First Main Lemma gives only a power relation; the formalization verifies the further ramification analysis, including the mathematically new wild dyadic case.
PDF · arXiv / full text · HAL · Lean code
A Local Proof of Langlands’s Second Main Lemma for Local Epsilon Factors over Nonarchimedean Local Fields
Fukuhiro Ueda · 2026
A local proof of Langlands’s Second Main Lemma in mixed and equal characteristic. The new point is the wild dyadic case, where the remaining sign is determined by comparing the finite sums in Lamprecht’s formula.
PDF · arXiv / full text · HAL · Langlands’s comments on the Second Main Lemma
Formalization of Langlands’s First Main Lemma for Local Epsilon Factors
Fukuhiro Ueda · 2026
A Lean 4 formalization of the First Main Lemma following the companion local proof, including local constants, ramification and finite-field identities, stationary classes, and the full case analysis.
PDF · HAL · Lean code
A Local Proof of Langlands’s First Main Lemma for Local Epsilon Factors over Nonarchimedean Local Fields
Fukuhiro Ueda · 2026
A complete purely local proof of Langlands’s First Main Lemma in both mixed and equal characteristic, reconstructing the Dwork–Langlands method and completing the missing endpoint, non-stable wild, and quadratic calculations.
PDF · HAL
Published papers
Crystalline comparison isomorphisms in p-adic Hodge theory: the absolutely unramified case
with Jilong Tong · Algebra & Number Theory 13 (2019), no. 7, 1509–1581
Constructs crystalline comparison isomorphisms for proper smooth formal schemes over an absolutely unramified base, allowing nontrivial coefficients and a relative version, using the pro-étale site.
arXiv / full text · journal
The Breuil–Mézard conjecture for non-scalar split residual representations
with Yongquan Hu · Annales Scientifiques de l’École Normale Supérieure 48 (2015), no. 6, 1383–1421
Proves the Breuil–Mézard conjecture for split non-scalar residual representations of the local Galois group by local methods; together with earlier cases this completes the conjecture for p ≥ 5. As a consequence, it removes the remaining local restriction in Kisin’s proof of the Fontaine–Mazur conjecture, yielding the corresponding two-dimensional modularity theorem.
arXiv / full text · journal
Overconvergent Families of Siegel–Hilbert Modular Forms
with Chung Pang Mok · Canadian Journal of Mathematics 67 (2015), no. 4, 893–922
Constructs one-parameter families of overconvergent Siegel–Hilbert modular forms, with applications to Galois representations attached to automorphic forms of non-cohomological weights.
arXiv / full text · journal
Modularity of Calabi–Yau varieties and conformal field theory
Science in China Series A: Mathematics 51 (2008), no. 6, 1135–1146
Studies modularity of Calabi–Yau varieties from the viewpoint of conformal field theory, expressing the modular forms of one-dimensional Calabi–Yau orbifolds as products of Dedekind eta functions.
publisher PDF · journal / DOI
Thesis
Families of p-adic Galois Representations
Ph.D. thesis, Massachusetts Institute of Technology, 2011 · advisor: Barry Mazur
Generalizes Kisin’s theory of finite-slope subspaces to arbitrary p-adic fields and studies finite-slope deformation rings, local Galois eigenvarieties, their geometry near de Rham points, and an infinite fern in local Galois deformation space.
MIT repository / full text