papers

Publications (24)

math.AG2026

Some terminal orders on 3-folds

Daniel Chan, Colin Ingalls

We produce the first known examples of non-trivial terminal local orders in the 3-dimensional case. We exhibit two different constructions. The first produces maximal orders with g…

math.NT2025

Zeta functions of orders on surfaces

Daniel Chan, Sean B. Lynch

In this manuscript, we give effective methods for computing the zeta function of maximal orders on surfaces.

math.RT2015

Moduli stacks of Serre stable representations in tilting theory

Daniel Chan, Boris Lerner

We introduce a new moduli stack, called the Serre stable moduli stack, which corresponds to studying families of point objects in an abelian category with a Serre functor. This all…

math.AG2021

The minimal model program for arithmetic surfaces enriched by a Brauer class

Daniel Chan, Colin Ingalls

We examine the noncommutative minimal model program for orders on arithmetic surfaces, or equivalently, arithmetic surfaces enriched by a Brauer class . When has prime ind…

math.RA2010

Twisted rings and moduli stacks of "fat" point modules in non-commutative projective geometry

Daniel Chan

The Hilbert scheme of point modules was introduced by Artin-Tate-Van den Bergh to study non-commutative graded algebras. The key tool is the construction of a map from the algebra…

math.AG2009

Non-commutative Mori contractions and $\PP^1$-bundles

Daniel Chan, Adam Nyman

We give a method for constructing maps from a non-commutative scheme to a commutative projective curve. With the aid of Artin-Zhang's abstract Hilbert schemes, this is used to cons…

math.AG2022

Noncommutative linear systems and noncommutative elliptic curves

Daniel Chan, Adam Nyman

In this paper we introduce a noncommutative analogue of the notion of linear system, which we call a helix in an a…

math.RA2011

Rational curves and ruled orders on surfaces

Daniel Chan, Kenneth Chan

We study ruled orders. These arise naturally in the Mori program for orders on projective surfaces and morally speaking are orders on a ruled surface ramified on a bisection and po…

math.RA2011

Conic bundles and Clifford algebras

Daniel Chan, Colin Ingalls

We discuss natural connections between three objects: quadratic forms with values in line bundles, conic bundles and quaternion orders. We use the even Clifford algebra, and the Br…

math.RA2020

Low dimensional orders of finite representation type

Daniel Chan, Colin Ingalls

In this paper, we study noncommutative surface singularities arising from orders. The singularities we study are mild in the sense that they have finite representation type or, equ…

math.RA2004

Numerically Calabi-Yau orders on surfaces

Daniel Chan, Rajesh Kulkarni

This is part of an ongoing program to classify maximal orders on surfaces via their ramification data. Del Pezzo and ruled orders have already been classified. In this paper, we cl…

math.AG2018

A representation theoretic study of noncommutative symmetric algebras

Daniel Chan, Adam Nyman

We study Van den Bergh's noncommutative symmetric algebra (over division rings) via Minamoto's theory of Fano algebras. In particular, we show $\mathbb{S}^{nc}…

math.AG2017

The minimal model program for b-log canonical divisors and applications

Daniel Chan, Kenneth Chan, Louis de Thanhoffer de Völcsey +8

We discuss the minimal model program for b-log varieties, which is a pair of a variety and a b-divisor, as a natural generalization of the minimal model program for ordinary log va…

math.RT2016

2-hereditary algebras and almost Fano weighted surfaces

Daniel Chan

Tilting bundles on a weighted projective line have been intensively studied by representation theorists since they give rise to a derived equivalence bet…

math.AG2024

A compact moduli of orbifold projective curves

Tarig Abdelgadir, Daniel Chan, Shinnosuke Okawa +1

We introduce the notion of stable orbifold projective curves, and show that the moduli stack of stable orbifold projective curves is isomorphic to the moduli stack of weighted poin…

math.AG2024

Tensor stable moduli stacks and refined representations of quivers

Tarig Abdelgadir, Daniel Chan

In this paper, we look at the problem of modular realisations of derived equivalences, and more generally, the problem of recovering a Deligne-Mumford stack and a bund…

math.AG2008

Moduli of bundles on exotic del Pezzo orders

Daniel Chan, Rajesh Kulkarni

Maximal orders of rank 4 on the projective plane, ramified on a smooth plane quartic are examples of exotic del Pezzo orders. We compute the possible Chern classes for line bundles…

math.RA2007

Canonical singularities of orders over surfaces

Daniel Chan, Paul Hacking, Colin Ingalls

We classify the possible ramification data and etale local structure of orders over surfaces with canonical singularities.

math.RA2008

Hilbert schemes for quantum planes are projective

Daniel Chan

We show that Hilbert schemes for quantum planes are projective.

math.AG2007

McKay correspondence for canonical orders

Daniel Chan

Canonical orders, introduced in the minimal model program for orders, are simultaneous generalisations of Kleinian singularities and their associated skew group rings. In this pape…

math.RA2026

Three-periodic helices on elliptic curves and their associated regular algebras

Daniel Chan, Adam Nyman

Let denote an algebraically closed field of characteristic zero and let denote a smooth elliptic curve over . Given a three-periodic elliptic helix $\underline{\mathcal{…

math.AG2025

Two-periodic elliptic helices: classification and geometry

Daniel Chan, Adam Nyman

Let denote an algebraically closed field of characteristic zero and let denote a smooth elliptic curve over . In this paper, motivated by work in \cite{CN}, we think of…

math.AG2025

Degenerations of orbifold curves as noncommutative varieties

Tarig Abdelgadir, Daniel Chan, Shinnosuke Okawa +1

Boundary points on the moduli space of pointed curves corresponding to collisions of marked points have modular interpretations as degenerate curves. In this paper, we study degene…

math.RA2022

Terminal orders on arithmetic surfaces

Daniel Chan, Colin Ingalls

The local structure of terminal Brauer classes on arithmetic surfaces were classified in [CI21] generalising the classification on geometric surfaces carried out in [CI05]. Part of…