Singular Rouquier Complexes

BGG complexes in singular blocks of category O

Using translation from the regular block, we construct and analyze properties of BGG complexes in singular blocks of BGG category ${\mathcal{O}}$. We provide criteria, in terms of the Kazhdan-Lusztig-Vogan polynomials, for such complexes to be exact. In the Koszul dual picture, exactness of BGG complexes is expressed as a certain condition on a generalized Verma flag of an indecomposable projective object in the corresponding block of parabolic category ${\mathcal{O}}$. In the second part of the paper, we construct BGG complexes in a more general setting of balanced quasi-hereditary algebras a…

Singular BGG complexes for the symplectic case

Using the Penrose transform, we construct analogues of the BGG (Bernstein-Gelfand-Gelfand) resolutions in certain singular infinitesimal characters, in the holomorphic geometric setting, over the Lagrangian Grassmannian. We prove the exactness of the constructed complex over the big affine cell.

Singular BGG complexes over isotropic 2-Grassmannian

We construct exact sequences of invariant differential operators acting on sections of certain homogeneous vector bundles in singular infinitesimal character, over the isotropic $2$-Grassmannian. This space is equal to $G/P$, where $G$ is $\operatorname{Sp}(2n,\mathbb{C})$, and $P$ its standard parabolic subgroup having the Levi factor $\operatorname{GL}(2,\mathbb{C}) \times \operatorname{Sp}(2n-4,\mathbb{C})$. The constructed sequences are analogues of the Bernstein-Gelfand-Gelfand resolutions. We do this by considering the Penrose transform over an appropriate double fibration. The result di…

The singular Yoneda category and the stabilization functor

For a noetherian ring $Λ$, the stabilization functor in the sense of Krause yields an embedding of the singularity category of $Λ$ into the homotopy category of acyclic complexes of injective $Λ$-modules. When $Λ$ contains a semisimple artinian subring $E$, we give an explicit description of the stabilization functor using the Hom complexes in the $E$-relative singular Yoneda dg category of $Λ$.

Derived varieties of complexes and Kostant's theorem for gl(m|n)

Given a graded vector space V, the variety of complexes Com(V) consists of all differentials making V into a cochain complex. This variety was first introduced by Buchsbaum and Eisenbud and later studied by Kempf, De Concini, Strickland and many other people. It is highly singular and can be seen as a proto-typical singular moduli space in algebraic geometry. We introduce a natural derived analog of Com(V) which is a smooth derived scheme RCom(V). It can be seen as classifying twisted complexes. We study the cohomology of the dg-algebra of regular functions om RCom(V). It turns out that the na…

A skein relation for singular Soergel bimodules

We study the skein relation that governs the HOMFLYPT invariant of links colored by one-column Young diagrams. Our main result is a categorification of this colored skein relation. This takes the form of a homotopy equivalence between two one-sided twisted complexes constructed from Rickard complexes of singular Soergel bimodules associated to braided webs. Along the way, we prove a conjecture of Beliakova--Habiro relating the colored 2-strand full twist complex with the categorical ribbon element for quantum $\mathfrak{sl}_2$.

A 型 Soergel 双模上的编织：半严格性与自然性

Braiding on type A Soergel bimodules: semistrictness and naturality

本文在具体 dg-模型中显式构造了 A 型 Soergel 双模链复形范畴上的编织结构，建立其半严格幺半 2-范畴框架，并给出编织自然性的高阶同伦数据。

双模诱导的奇异等价与二次单项式代数

Singular equivalences induced by bimodules and quadratic monomial algebras

本文研究双模张量函子诱导奇异等价的条件，并构造显式双模以建立二次单项式代数与根平方零相关代数之间的带层级奇异等价。

Soergel 双模的辫子幺半 $(\infty,2)$-范畴

A braided monoidal $(\infty,2)$-category of Soergel bimodules

本文首次将 Hecke 辫子幺半范畴范畴化为 $\mathbb{E}_2$-幺半 $(\infty,2)$-范畴，基于 Soergel 双模链复形，旨在控制同伦相干链环同调及 4/5 维 TQFT，并发展了分解系统工具。