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The derived McKay correspondence conjecture says that there is an equivalence of triangulated categories between the bounded derived categories of commutative and non-commutative crepant resolutions of a Gorenstein singularity. We will…

Algebraic Geometry · Mathematics 2024-10-22 Yujiro Kawamata

We prove that every simple flop of type $D_5$, i.e., resolved by blowups with exceptional divisor isomorphic to a generalized Grassmann bundle with fiber $OG(4, 10)$, induces a derived equivalence. This provides new evidence for the DK…

Algebraic Geometry · Mathematics 2025-10-09 Marco Rampazzo , Ying Xie

The local simple $9$-fold flop of Grassmannian type is a birational transformation between total spaces of vector bundles on the Grassmannians $\mathrm{Gr}(2, 5)$ and $\mathrm{Gr}(3, 5)$. We produce four different derived equivalences which…

Algebraic Geometry · Mathematics 2025-10-08 Will Donovan , Wahei Hara , Michał Kapustka , Marco Rampazzo

Categorical resolutions of singularities are a replacement of resolution of singularities within the realm of triangulated categories. They allow the study of the derived category of a singular variety $X$ via a triangulated category that…

Algebraic Geometry · Mathematics 2025-12-05 Nicolás Vilches

A conjecture of Orlov predicts that derived equivalent smooth projective varieties over a field have isomorphic Chow motives. The conjecture is known for curves, and was recently observed for surfaces by Huybrechts. In this paper we focus…

Algebraic Geometry · Mathematics 2020-02-26 Jeff Achter , Sebastian Casalaina-Martin , Charles Vial

This note aims to clarify the deep relationship between birational modifications of a variety and semiorthogonal decompositions of its derived category of coherent sheaves. The result is a conjecture on the existence and properties of…

Algebraic Geometry · Mathematics 2024-03-28 Daniel Halpern-Leistner

Let $X$ and $Y$ be smooth projective varieties over $\mathbb{C}$. They are called {\it $D$-equivalent} if their derived categories of bounded complexes of coherent sheaves are equivalent as triangulated categories, while {\it…

Algebraic Geometry · Mathematics 2007-05-23 Yujiro Kawamata

Originally a technical tool, the derived category of coherent sheaves over an algebraic variety has become over the last twenty years an important invariant in the birational study of algebraic varieties. Problems of birational invariance…

Algebraic Geometry · Mathematics 2007-05-23 Raphael Rouquier

The paper is Part III of our ongoing project to study a case of Crepant Transformation Conjecture: K-equivalence Conjecture for ordinary flops. In this paper we prove the invariance of quantum rings for general ordinary flops, whose local…

Algebraic Geometry · Mathematics 2014-04-01 Y. -P. Lee , H. -W. Lin , F. Qu , C. -L. Wang

We disprove a conjecture of Kuznetsov--Shinder, which posits that $D$-equivalent simply connected varieties are $L$-equivalent, by constructing a counterexample using moduli spaces of sheaves on K3 surfaces.

Algebraic Geometry · Mathematics 2026-02-11 Reinder Meinsma

It is an open conjecture of Orlov that the bounded derived category of coherent sheaves of a smooth projective variety determines its Chow motive with rational coefficients. In this master's thesis we introduce a category of \emph{perfect…

Algebraic Geometry · Mathematics 2013-10-02 A. Kh. Yusufzai

We show that the Friedlander-Mazur conjecture holds for a complex smooth projective variety X of dimension three implies the standard conjectures hold for X. This together with a result of Friedlander yields the equivalence of the two…

Algebraic Geometry · Mathematics 2021-11-05 Jin Cao , Wenchuan Hu

Most of the known examples of derived categories of small resolutions arise as the derived category of the endormorphism algebra of tilting bundles or complexes. Given two resolutions connected by a flop, if the strict transform of a…

Algebraic Geometry · Mathematics 2025-05-13 Ananyo Dan , Yirui Xiong

We show that Braun-Chuang-Lazarev's derived quotient prorepresents a naturally defined noncommutative derived deformation functor. Given a noncommutative partial resolution of a Gorenstein algebra, we show that the associated derived…

Algebraic Geometry · Mathematics 2018-11-29 Matt Booth

Given a birational modification $X \to Y$ of complex projective varieties with fiber dimension 1 and rational singularities, consider the main component of Bridgeland's moduli space $W \to Y$ of perverse point sheaves on $X/Y$. We give…

Algebraic Geometry · Mathematics 2007-05-23 Dan Abramovich , Jiun C. Chen

We prove an equivalence of triangulated categories between Orlov's triangulated category of singularities for a Gorenstein cyclic quotient singularity and the derived category of representations of a quiver with relations which is obtained…

Algebraic Geometry · Mathematics 2009-12-24 Kazushi Ueda

Given a nontrivial semi-orthogonal decomposition $\Perf(\X)=\langle \mathcal{A},\mathcal{B}\rangle$, and assume that the base locus of $\omega_{\X}$ is a proper closed subset, it was proved by Kotaro Kawatani and Shinnosuke Okawa that all…

Algebraic Geometry · Mathematics 2021-12-21 Xun Lin

Perverse schobers are conjectural categorical analogs of perverse sheaves. We show that such structures appear naturally in Homological Minimal Model Program which studies the effect of birational transformations such as flops, on the…

Algebraic Geometry · Mathematics 2018-01-26 Alexey Bondal , Mikhail Kapranov , Vadim Schechtman

The coherent-constructible correspondence is a relationship between coherent sheaves on a toric variety X, and constructible sheaves on a real torus T. This was discovered by Bondal, and explored in the equivariant setting by Fang, Liu,…

Algebraic Geometry · Mathematics 2014-03-07 Sarah Scherotzke , Nicolò Sibilla

We describe a new example of a flop in 5-dimensions, due to Roland Abuaf, with the nice feature that the contracting loci on either side are not isomorphic. We prove that the two sides are derived equivalent.

Algebraic Geometry · Mathematics 2017-05-04 Ed Segal