activity
20202026
most citedThe minimal exponent and -rationality for local complete intersections

2 citations · 5 across the 19 of their papers we have counts for

collaborators

23 papers

math.AG2026

A Hodge module construction of relative Du Bois complexes

Bradley Dirks

We construct relative Du Bois and relative intersection Du Bois complexes for smooth-factorizable morphisms to a smooth complex base using relative de Rham complexes of mixed Hodge…

math.AG2026

Filtrations on Local Cohomology and Injectivity Theorems

Qianyu Chen, Bradley Dirks, Sebastian Olano

We prove that the Hodge filtration on local cohomology is contained in the symbolic Ext filtration, and hence in the usual Ext filtration, answering a question of Mustata and Popa.…

math.AG2026

-nilpotence and Hodge filtrations beyond isolated singularities

Bradley Dirks, Jakub Witaszek

We give Hodge-theoretic characterizations of characteristic-zero varieties of open -nilpotent and open weakly -nilpotent type, extending a result of Srinivas and Takagi beyon…

math.AG2026

A Hodge Theoretic Generalization of -Homology Manifolds II: Local Complete Intersections

Bradley Dirks, Sebastian Olano, Debaditya Raychaudhury

Recently, the authors introduced and studied a singularity invariant of a complex algebraic variety , written $\HRH(Z)$ (for ``Hodge rational homology'' manifold level). In this…

math.AG2026

Microlocal Bernstein--Sato polynomials on singular ambient varieties

Bradley Dirks, Michael Perlman

We introduce the microlocal Bernstein--Sato polynomial of a function on a possibly singular ambient variety, extending the theory of Saito. We show that, contrary to the smooth amb…

math.AG2026

Characterization and finite descent of local cohomological invariants

Bradley Dirks, Sebastian Olano, Debaditya Raychaudhury

We provide simple ``left-inverse characterizations'' of the recently introduced singularity invariants , , and of an equidimensional variety . Combini…

math.AG2026

Hodge theory of secant varieties

Qianyu Chen, Bradley Dirks, Sebastian Olano +1

We study the local cohomology modules for the secant variety of lines of a smooth projective variety and for higher secant varieties of smooth projective curves. We show that t…

math.AG2025

Partial Cohomologically Complete Intersections via Hodge Theory

Qianyu Chen, Bradley Dirks, Sebastian Olano

We introduce an invariant associated to any complex algebraic variety , which for varieties with isolated singularities measures the failure of dual Kodaira-Akizuki-Nakan…

math.AG2025

Multiplier modules, -filtrations and Bernstein-Sato polynomials on singular ambient varieties

Bradley Dirks

We show that the relation between multiplier ideals and -filtration on the structure sheaf due to Budur-Mustaţă-Saito generalizes to singular irreducible varieties, by replacing…

math.AG2025

Hirzebruch-Milnor classes of local complete intersections, minimal exponent, and applications to higher singularities

Bradley Dirks, Laurenţiu Maxim, Sebastián Olano

In this paper we use the deformation to the normal cone and the corresponding Verdier-Saito specialization to define and study (spectral) Hirzebruch-Milnor type homology characteri…

math.AG2025

A Hodge Theoretic generalization of -Homology Manifolds I: General Case

Bradley Dirks, Sebastian Olano, Debaditya Raychaudhury

We study a natural Hodge-theoretic generalization of rational (or -)homology manifolds through an invariant $\HRH(Z)$ attached to a complex algebraic variety . The d…

math.AG2024

Restrictions of mixed Hodge modules using generalized V-filtrations

Qianyu Chen, Bradley Dirks, Sebastian Olano

We study generalized -filtrations, defined by Sabbah, on -modules underlying mixed Hodge modules on . Using cyclic covers, we compare these filt…

math.AG2024

Fourier transform and Radon transform for mixed Hodge modules

Bradley Dirks

We give a generalization to bi-filtered -modules underlying mixed Hodge modules of the relation between microlocalization along and va…

math.AG2024★ 1 cited

The minimal exponent of cones over smooth complete intersection projective varieties

Qianyu Chen, Bradley Dirks, Mircea Mustaţă

We compute the minimal exponent of the affine cone over a complete intersection of smooth projective hypersurfaces intersecting transversely. The upper bound for the minimal expone…

math.AG2024

An introduction to -filtrations

Qianyu Chen, Bradley Dirks, Mircea Mustaţă

We give an introduction to the theory of -filtrations of Malgrange and Kashiwara. After discussing the basic properties of this construction (in the case of a smooth hypersurfac…

math.AG2023★ 1 cited

Some applications of microlocalization for local complete intersection subvarieties

Bradley Dirks

Saito's microlocalization construction has been used to great effect in understanding hypersurface singularities. In this paper, we introduce what we believe to be a suitable analo…

math.AG2023

Verdier specialization and restrictions of Hodge modules

Qianyu Chen, Bradley Dirks, Morihiko Saito

We give an explicit formula to express the cohomological pullback functors of Hodge modules under closed immersions of smooth varieties using Verdier specializations and -filtra…

math.AG2022★ 2 cited

The minimal exponent and -rationality for local complete intersections

Qianyu Chen, Bradley Dirks, Mircea Mustaţă

We show that if is a local complete intersection subvariety of a smooth complex variety , of pure codimension , then has -rational singularities if and only if $\w…

math.AG2022

V-filtrations and minimal exponents for locally complete intersection singularities

Qianyu Chen, Bradley Dirks, Mircea Mustaţă +1

We define and study a notion of minimal exponent for a locally complete intersection subscheme of a smooth complex algebraic variety , extending the invariant defined by Sai…

math.AG2021★ 1 cited

On -filtration, Hodge filtration and Fourier transform

Qianyu Chen, Bradley Dirks

For a closed immersion of smooth varieties, we study how the -filtration along and the Hodge filtration on a mixed Hodge module on interact with each o…

math.AG2020

Minimal exponents of hyperplane sections: a conjecture of Teissier

Bradley Dirks, Mircea Mustata

We prove a conjecture of Teissier asserting that if has an isolated singularity at and is a smooth hypersurface through , then $\widetildeα_P(f)\geq \widetildeα_P(f\…

math.AG2020

The Hilbert series of Hodge ideals of hyperplane arrangements

Bradley Dirks, Mircea Mustata

Given a reduced effective divisor D on a smooth variety X, we describe the generating function for the classes of the Hodge ideals of D in the Grothendieck group of coherent sheave…

math.AG2020

Upper bounds for roots of B-functions, following Kashiwara and Lichtin

Bradley Dirks, Mircea Mustata

By building on a method introduced by Kashiwara and refined by Lichtin, we give upper bounds for the roots of certain b-functions associated to a regular function f in terms of a l…