Cohen-Macaulayness of Local Models via Shellability of the Admissible Set

This paper proves that augmented admissible sets in Iwahori-Weyl groups are dual EL-shellable, thereby resolving a conjecture of Görtz and establishing the Cohen-Macaulayness of special fibers for local models with parahoric level structure—including previously open cases in residue characteristic 2 and non-reduced root systems—through a characteristic-free, intrinsic construction that yields an explicit shelling and inductive building procedure.

Xuhua He, Felix Schremmer, Qingchao YuMon, 09 Ma🔢 math

Unitary and Nonunitary Representations of the Heisenberg-Weyl Lie Algebra

This paper provides a detailed Lie-algebraic analysis of the Heisenberg-Weyl Lie algebra by constructing explicit unitary intertwining operators for tensor products of its Schrödinger representations and proving that finite-dimensional irreducible representations of the symplectic Lie algebra sp2n+2(R)\mathfrak{sp}_{2n+2}(\mathbb{R}) yield a large family of finite-dimensional, nonunitary indecomposable representations when restricted to hwn\mathfrak{hw}_n.

Andrew Douglas, Hubert de Guise, Joe RepkaMon, 09 Ma🔢 math

Stability conditions on noncommutative crepant resolutions of 3-dimensional isolated singularities

This paper constructs a mutation cone and a corresponding wall-and-chamber structure for maximal modifying modules over 3-dimensional Gorenstein isolated singularities, proving that the tilting-noetherian property holds if and only if all such modules are mutation-connected, and establishing a regular covering map from a specific subspace of Bridgeland stability conditions to the complexified mutation cone to describe the associated autoequivalence group.

Wahei Hara, Yuki Hirano2026-03-06🔢 math

Minimal Projective Resolutions, Möbius Inversion, and Bottleneck Stability

This paper establishes a stability theorem for minimal projective resolutions of modules over finite metric posets by proving that a newly defined bottleneck distance between resolutions is bounded above by the Galois transport distance, thereby generalizing classical bottleneck stability to multiparameter persistence and providing a stability framework for Möbius homology.

Hideto Asashiba, Amit K. Patel2026-03-06🔢 math

Reflection Theory of Nichols Algebras over Coquasi-Hopf Algebras with Bijective Antipode

This paper generalizes the reflection theory of Nichols algebras to arbitrary coquasi-Hopf algebras with bijective antipode by establishing a braided monoidal equivalence that links finite-dimensional irreducible Yetter-Drinfeld modules admitting all reflections to semi-Cartan graphs, a framework applied to prove that a specific rank three example constitutes an affine Nichols algebra.

Bowen Li, Gongxiang Liu2026-03-06🔢 math