Stably semiorthogonally indecomposable varieties

This paper introduces the concept of noncommutatively stably semiorthogonally indecomposable (NSSI) varieties, proves that varieties with finite Albanese morphisms and certain fibrations possess this property, and demonstrates that NSSI varieties ensure the indecomposability of their subvarieties' derived categories and the absence of phantom subcategories in specific products like C×P1C \times \mathbb{P}^1.

Dmitrii Pirozhkov2026-03-11🔢 math

Filtered formal groups, Cartier duality, and derived algebraic geometry

This paper develops a theory of filtered formal groups and their Cartier duality, utilizes a deformation to the normal cone in derived algebraic geometry to establish a unicity result linking adic filtrations to Gm\mathbb{G}_m-equivariant degenerations, and applies these findings to recover the filtration on the filtered circle and lift Hochschild homology invariants to spectral algebraic geometry.

Tasos Moulinos2026-03-11🔢 math

On a decomposition of pp-adic Coxeter orbits

This paper establishes that for classical unramified reductive groups over non-archimedean local fields, specific pp-adic Deligne–Lusztig spaces Xw(b)X_w(b) associated with basic elements bb and Coxeter elements ww decompose into disjoint unions of translates of integral pp-adic Deligne–Lusztig spaces, while also extending results on rational conjugacy classes of unramified tori and proving a loop version of Frobenius-twisted Steinberg's cross section.

Alexander B. Ivanov2026-03-11🔢 math

On Bruhat-Tits theory over a higher dimensional base

This paper generalizes Bruhat-Tits theory to higher-dimensional bases by defining and proving the schematic nature of nn-bounded subgroups associated with concave functions on root systems, thereby constructing smooth group schemes adapted to normal crossing divisors and extending these results to mixed characteristic settings with applications to wonderful embeddings and surface singularities.

Vikraman Balaji, Yashonidhi Pandey2026-03-11🔢 math

On algebraically coisotropic submanifolds of holomorphic symplectic manifolds

This paper investigates algebraically coisotropic submanifolds in holomorphic symplectic projective manifolds, proving that when the ambient space is an abelian variety or the submanifold has a semi-ample canonical bundle, the pair decomposes into a product involving a Lagrangian submanifold, while also noting the non-existence of such Lagrangian submanifolds on sufficiently general abelian varieties.

Ekaterina Amerik, Frédéric Campana2026-03-11🔢 math