A combinatorial Fourier transform for quiver representation varieties in type A
|
|
- Amie York
- 5 years ago
- Views:
Transcription
1 A combinatorial Fourier transform for quiver representation varieties in type A Pramod N. Achar, Maitreyee Kulkarni, and Jacob P. Matherne Louisiana State University and University of Massachusetts Amherst April 8, 8 Maurice Auslander Distinguished Lectures and International Conference
2 Goal Consider the quiver ÝÑ ÝÑ ÝÑ. Notation: Epwq - space of representations for dimension vector w pw,..., w n q Gpwq GLpw q ˆ ˆ GLpw n q w pw n,..., w q - the reverse dimension vector / 7
3 Goal Consider the quiver ÝÑ ÝÑ ÝÑ. Notation: Epwq - space of representations for dimension vector w pw,..., w n q Gpwq GLpw q ˆ ˆ GLpw n q w pw n,..., w q - the reverse dimension vector Can we give a combinatorial description of the Fourier Sato transform: D b Gpwq pepwqq T ÝÑ D b Gpw q pepw qq F ÞÝÑ q! q pfqrdim Epwqs for simple perverse sheaves F? / 7
4 / 7 Outline Quiver representation varieties Some combinatorics Fourier Sato transform Combinatorial Fourier transform
5 / 7 Outline Quiver representation varieties Some combinatorics Fourier Sato transform Combinatorial Fourier transform
6 4 / 7 Quiver representations Consider the type A n equioriented quiver Q n ÝÑ ÝÑ ÝÑ. A quiver representation is: A finite-dimensional C-vector space M i for each vertex. A linear map x i for each arrow. x M x M x n M n
7 4 / 7 Quiver representations Consider the type A n equioriented quiver Q n ÝÑ ÝÑ ÝÑ. A quiver representation is: A finite-dimensional C-vector space M i for each vertex. A linear map x i for each arrow. x M x M x n M n ReppQ n q - abelian category of finite-dimensional complex representations of Q n
8 5 / 7 Quiver representation varieties Fix a dimension vector w pw, w,..., w n q. A quiver representation variety Epwq is the space of all quiver representations for a fixed dimension vector w. Note that Epwq is an affine variety: Epwq» A w w `w w ` `w n w n.
9 Quiver representation varieties Fix a dimension vector w pw, w,..., w n q. A quiver representation variety Epwq is the space of all quiver representations for a fixed dimension vector w. Note that Epwq is an affine variety: Epwq» A w w `w w ` `w n w n. Gpwq GLpw q ˆ ˆ GLpw n q acts on Epwq by pg,..., g n q px,..., x n q pg x g,..., g nx n g n q giving it a stratification by orbits. Note that two points x, y P Epwq are in the same Gpwq-orbit if and only if they are isomorphic objects of ReppQ n q. 5 / 7
10 6 / 7 Classifying the orbits Theorem (Gabriel s Theorem) There is a bijection tindec. objects in ReppQ n qu{ ÐÑ tpos. roots for A n root systemu.
11 6 / 7 Classifying the orbits Theorem (Gabriel s Theorem) There is a bijection tindec. objects in ReppQ n qu{ ÐÑ tpos. roots for A n root systemu. To an indecomposable representation R ij Ñ Ñ Ñ C vertex i id ÝÑ ÝÑ id we associate its dimension vector, the positive root C Ñ Ñ Ñ. vertex j γ ij p,...,,,...,,,..., q. position i position j
12 6 / 7 Classifying the orbits Theorem (Gabriel s Theorem) There is a bijection tindec. objects in ReppQ n qu{ ÐÑ tpos. roots for A n root systemu. To an indecomposable representation R ij Ñ Ñ Ñ C vertex i id ÝÑ ÝÑ id we associate its dimension vector, the positive root Corollary There is a bijection C Ñ Ñ Ñ. vertex j γ ij p,...,,,...,,,..., q. position i position j tgpwq-orbits in Epwqu ÐÑ Bpwq : tb ij ÿ b ij γ ij wu.
13 7 / 7 Outline Quiver representation varieties Some combinatorics Fourier Sato transform Combinatorial Fourier transform
14 8 / 7 Triangular arrays ladder chute Define the set Ppwq of triangular arrays of nonnegative integers such the entries in the j th chute sum to w j. Ladders are weakly decreasing.
15 8 / 7 Triangular arrays ladder chute Define the set Ppwq of triangular arrays of nonnegative integers such the entries in the j th chute sum to w j. Ladders are weakly decreasing. For w p,, q, P Ppwq We will write y ij for the entry in the i th chute and j th column.
16 9 / 7 Classifying the orbits combinatorially Lemma (Achar K. Matherne) There is a bijection Bpwq : tb ij ÿ b ij γ ij wu ÐÑ Ppwq. b b b ` b b b ` b b ` b ` b b b b b b b
17 / 7 Running Example (A ) Let w p,, q. C C C rank C C C rank C C C rank rank C C C
18 / 7 Partial orders on Ppwq If Y P Ppwq, we write O Y for the corresponding Gpwq-orbit in Epwq. Let Y, Y P Ppwq.
19 / 7 Partial orders on Ppwq If Y P Ppwq, we write O Y for the corresponding Gpwq-orbit in Epwq. Let Y, Y P Ppwq. Geometric partial order on Ppwq: Y ď g Y if and only if O Y Ă O Y. Combinatorial partial order on Ppwq: Y ď c Y if for all i and j, jÿ jÿ y ik ě k k y ik.
20 / 7 Partial orders on Ppwq If Y P Ppwq, we write O Y for the corresponding Gpwq-orbit in Epwq. Let Y, Y P Ppwq. Geometric partial order on Ppwq: Y ď g Y if and only if O Y Ă O Y. Combinatorial partial order on Ppwq: Y ď c Y if for all i and j, jÿ jÿ y ik ě k k y ik. Theorem (Achar K. Matherne) The geometric and combinatorial partial orders coincide.
21 Running Example (A ) / 7
22 / 7
23 4 / 7 Some observations from the combinatorics Let Y P Ppwq. Denote by MpYq a representation in the orbit O Y.
24 4 / 7 Some observations from the combinatorics Let Y P Ppwq. Denote by MpYq a representation in the orbit O Y. Theorem (Achar K. Matherne) ÿ dim O Y y ij y ik ` ďiďn ďjăkďn i` ÿ ďiďn ďjăkďn i` y i`,j y ik.
25 4 / 7 Some observations from the combinatorics Let Y P Ppwq. Denote by MpYq a representation in the orbit O Y. Theorem (Achar K. Matherne) ÿ dim O Y y ij y ik ` ďiďn ďjăkďn i` ÿ ďiďn ďjăkďn i` y i`,j y ik. MpYq is an injective object in ReppQ n q if and only if Y is constant along ladders. MpYq is a projective object in ReppQ n q if and only if Y has nonzero entries only in the last ladder.
26 5 / 7 Outline Quiver representation varieties Some combinatorics Fourier Sato transform Combinatorial Fourier transform
27 6 / 7 Some basics about perverse sheaves Perverse sheaves - complexes of sheaves that encode information about the singularities of a space (intersection cohomology)
28 Some basics about perverse sheaves Perverse sheaves - complexes of sheaves that encode information about the singularities of a space (intersection cohomology) ÐÑ tgpwq-orbits in Epwqu tsimple perverse sheaves on Epwqu. O Y ÞÝÑ ICpO Y q 6 / 7
29 Some basics about perverse sheaves Perverse sheaves - complexes of sheaves that encode information about the singularities of a space (intersection cohomology) ÐÑ tgpwq-orbits in Epwqu tsimple perverse sheaves on Epwqu. O Y ÞÝÑ ICpO Y q So, get a bijection: ÐÑ Ppwq tsimple perverse sheaves on Epwqu. Y ÞÝÑ ICpO Y q 6 / 7
30 7 / 7 Fourier Sato transform Can we give a combinatorial description of the Fourier Sato transform: D b Gpwq pepwqq for simple perverse sheaves F? T ÝÑ D b Gpw q pepw qq F ÞÝÑ F ^rdim Epwqs
31 8 / 7 Running example Ppwq Ppw q
32 9 / 7 Some properties and applications of the Fourier transform Properties: t-exact for the perverse t-structure and sends simples to simples. equivalence of categories almost an involution
33 9 / 7 Some properties and applications of the Fourier transform Properties: t-exact for the perverse t-structure and sends simples to simples. equivalence of categories almost an involution Applications: character formula for quantum loop algebras uses Fourier transform on graded quiver varieties (Nakajima) monoidal categorification of certain cluster algebras (Nakajima)
34 / 7 Outline Quiver representation varieties Some combinatorics Fourier Sato transform Combinatorial Fourier transform
35 / 7 Combinatorial Fourier transform Theorem (Achar K. Matherne) There is a bijection T Ppwq ÝÑ Ppw q defined inductively by T Y y,n τ y,n n τ y,n y,n n τ y n, y n, y n, TpY q where Tpaq a.
36 / 7 Sliding at j j th chute Define τ j : Ppwq Ñ Ppw ` e `... ` e j q by: Add as far down the j th chute as possible, drawing an impassable vertical line there. Repeat for chutes j,..., not crossing lines.
37 / 7 Example of T T T T τ τ
38 4 / 7 Running example Ppwq Ppw q
39 5 / 7 Main theorem Theorem (Achar K. Matherne) The bijection T : Ppwq Ñ Ppw q determines T : D b Gpwq pepwqq Ñ Db Gpw q pepw qq for simple perverse sheaves; that is, TpICpO Y qq ICpO TpYq q.
40 Outline of the proof Geometric Fourier transform Combinatorial Fourier transform
41 Outline of the proof Geometric Fourier transform Combinatorial Fourier transform Multisegment duality Bpwq Ñ Bpw q
42 Outline of the proof Geometric Unique dense Fourier transform open orbit in the commuting variety Knight-Zelevinsky Combinatorial Fourier transform Multisegment duality Bpwq Ñ Bpw q
43 Outline of the proof Unique dense open orbit in the commuting variety Pyasetskiĭ Evens Mirković Geometric Fourier transform Knight-Zelevinsky Combinatorial Fourier transform Multisegment duality Bpwq Ñ Bpw q
44 Outline of the proof Unique dense open orbit in the commuting variety Pyasetskiĭ Evens Mirković A K M Geometric Fourier transform Knight-Zelevinsky Combinatorial Fourier transform Multisegment duality Bpwq Ñ Bpw q
45 Outline of the proof Unique dense open orbit in the commuting variety Pyasetskiĭ Evens Mirković A K M Geometric Fourier transform Knight-Zelevinsky Combinatorial Fourier transform Multisegment duality Bpwq Ñ Bpw q
46 Outline of the proof Unique dense open orbit in the commuting variety Pyasetskiĭ Evens Mirković A K M Geometric Fourier transform Knight-Zelevinsky Combinatorial Fourier transform Multisegment duality Bpwq Ñ Bpw q
47 Outline of the proof Unique dense open orbit in the commuting variety Pyasetskiĭ Evens Mirković A K M Geometric Fourier transform Knight-Zelevinsky Combinatorial Fourier transform Multisegment duality Bpwq Ñ Bpw q A K M Inverse combinatorial Fourier transform 6 / 7
48 7 / 7
49 Thanks! 7 / 7
Examples of Semi-Invariants of Quivers
Examples of Semi-Invariants of Quivers June, 00 K is an algebraically closed field. Types of Quivers Quivers with finitely many isomorphism classes of indecomposable representations are of finite representation
More informationQ(x n+1,..., x m ) in n independent variables
Cluster algebras of geometric type (Fomin / Zelevinsky) m n positive integers ambient field F of rational functions over Q(x n+1,..., x m ) in n independent variables Definition: A seed in F is a pair
More informationIC of subvarieties. Logarithmic perversity. Hyperplane complements.
12. Lecture 12: Examples of perverse sheaves 12.1. IC of subvarieties. As above we consider the middle perversity m and a Whitney stratified space of dimension n with even dimensional strata. Let Y denote
More informationH(G(Q p )//G(Z p )) = C c (SL n (Z p )\ SL n (Q p )/ SL n (Z p )).
92 19. Perverse sheaves on the affine Grassmannian 19.1. Spherical Hecke algebra. The Hecke algebra H(G(Q p )//G(Z p )) resp. H(G(F q ((T ))//G(F q [[T ]])) etc. of locally constant compactly supported
More informationCategories of noncrossing partitions
Categories of noncrossing partitions Kiyoshi Igusa, Brandeis University KIAS, Dec 15, 214 Topology of categories The classifying space of a small category C is a union of simplices k : BC = X X 1 X k k
More informationLECTURE 11: SOERGEL BIMODULES
LECTURE 11: SOERGEL BIMODULES IVAN LOSEV Introduction In this lecture we continue to study the category O 0 and explain some ideas towards the proof of the Kazhdan-Lusztig conjecture. We start by introducing
More informationREPRESENTATION THEORY. WEEKS 10 11
REPRESENTATION THEORY. WEEKS 10 11 1. Representations of quivers I follow here Crawley-Boevey lectures trying to give more details concerning extensions and exact sequences. A quiver is an oriented graph.
More informationR-matrices, affine quantum groups and applications
R-matrices, affine quantum groups and applications From a mini-course given by David Hernandez at Erwin Schrödinger Institute in January 2017 Abstract R-matrices are solutions of the quantum Yang-Baxter
More informationThe preprojective algebra revisited
The preprojective algebra revisited Helmut Lenzing Universität Paderborn Auslander Conference Woodshole 2015 H. Lenzing Preprojective algebra 1 / 1 Aim of the talk Aim of the talk My talk is going to review
More informationMaximal Green Sequences via Quiver Semi-Invariants
Maximal Green Sequences via Quiver Semi-Invariants Stephen Hermes Wellesley College, Wellesley, MA Maurice Auslander Distinguished Lectures and International Conference Woods Hole May 3, 2015 Preliminaries
More informationCharacter sheaves and modular generalized Springer correspondence Part 2: The generalized Springer correspondence
Character sheaves and modular generalized Springer correspondence Part 2: The generalized Springer correspondence Anthony Henderson (joint with Pramod Achar, Daniel Juteau, Simon Riche) University of Sydney
More informationDimension of the mesh algebra of a finite Auslander-Reiten quiver. Ragnar-Olaf Buchweitz and Shiping Liu
Dimension of the mesh algebra of a finite Auslander-Reiten quiver Ragnar-Olaf Buchweitz and Shiping Liu Abstract. We show that the dimension of the mesh algebra of a finite Auslander-Reiten quiver over
More informationQUANTUM F -POLYNOMIALS IN THE THEORY OF CLUSTER ALGEBRAS. A dissertation presented by Thao Tran to The Department of Mathematics
QUANTUM F -POLYNOMIALS IN THE THEORY OF CLUSTER ALGEBRAS A dissertation presented by Thao Tran to The Department of Mathematics In partial fulfillment of the requirements for the degree of Doctor of Philosophy
More informationLattice Properties of Oriented Exchange Graphs
1 / 31 Lattice Properties of Oriented Exchange Graphs Al Garver (joint with Thomas McConville) Positive Grassmannians: Applications to integrable systems and super Yang-Mills scattering amplitudes July
More informationQUIVERS AND LATTICES.
QUIVERS AND LATTICES. KEVIN MCGERTY We will discuss two classification results in quite different areas which turn out to have the same answer. This note is an slightly expanded version of the talk given
More information1. Quivers and their representations: Basic definitions and examples.
1 Quivers and their representations: Basic definitions and examples 11 Quivers A quiver Q (sometimes also called a directed graph) consists of vertices and oriented edges (arrows): loops and multiple arrows
More informationQuiver mutations. Tensor diagrams and cluster algebras
Maurice Auslander Distinguished Lectures April 20-21, 2013 Sergey Fomin (University of Michigan) Quiver mutations based on joint work with Andrei Zelevinsky Tensor diagrams and cluster algebras based on
More informationDonaldson Thomas invariants for A-type square product quivers
Donaldson Thomas invariants for A-type square product quivers Justin Allman (Joint work with Richárd Rimányi 2 ) US Naval Academy 2 UNC Chapel Hill 4th Conference on Geometric Methods in Representation
More informationBases for Cluster Algebras from Surfaces
Bases for Cluster Algebras from Surfaces Gregg Musiker (U. Minnesota), Ralf Schiffler (U. Conn.), and Lauren Williams (UC Berkeley) Bay Area Discrete Math Day Saint Mary s College of California November
More informationThe Terwilliger Algebras of Group Association Schemes
The Terwilliger Algebras of Group Association Schemes Eiichi Bannai Akihiro Munemasa The Terwilliger algebra of an association scheme was introduced by Paul Terwilliger [7] in order to study P-and Q-polynomial
More informationMAT 5330 Algebraic Geometry: Quiver Varieties
MAT 5330 Algebraic Geometry: Quiver Varieties Joel Lemay 1 Abstract Lie algebras have become of central importance in modern mathematics and some of the most important types of Lie algebras are Kac-Moody
More informationOn the Homology of the Ginzburg Algebra
On the Homology of the Ginzburg Algebra Stephen Hermes Brandeis University, Waltham, MA Maurice Auslander Distinguished Lectures and International Conference Woodshole, MA April 23, 2013 Stephen Hermes
More informationCombinatorial Structures
Combinatorial Structures Contents 1 Permutations 1 Partitions.1 Ferrers diagrams....................................... Skew diagrams........................................ Dominance order......................................
More informationCHARACTER SHEAVES ON UNIPOTENT GROUPS IN CHARACTERISTIC p > 0. Mitya Boyarchenko Vladimir Drinfeld. University of Chicago
CHARACTER SHEAVES ON UNIPOTENT GROUPS IN CHARACTERISTIC p > 0 Mitya Boyarchenko Vladimir Drinfeld University of Chicago Some historical comments A geometric approach to representation theory for unipotent
More informationA note on standard equivalences
Bull. London Math. Soc. 48 (2016) 797 801 C 2016 London Mathematical Society doi:10.1112/blms/bdw038 A note on standard equivalences Xiao-Wu Chen Abstract We prove that any derived equivalence between
More informationarxiv: v2 [math.rt] 16 Mar 2018
THE COXETER TRANSFORMATION ON COMINUSCULE POSETS EMINE YILDIRIM arxiv:1710.10632v2 [math.rt] 16 Mar 2018 Abstract. Let J(C) be the poset of order ideals of a cominuscule poset C where C comes from two
More information5 Quiver Representations
5 Quiver Representations 5. Problems Problem 5.. Field embeddings. Recall that k(y,..., y m ) denotes the field of rational functions of y,..., y m over a field k. Let f : k[x,..., x n ] k(y,..., y m )
More informationTilting exotic sheaves, parity sheaves on affine Grassmannians, and the Mirković Vilonen conjecture
Tilting exotic sheaves, parity sheaves on affine Grassmannians, and the Mirković Vilonen conjecture (joint work with C. Mautner) Simon Riche CNRS Université Blaise Pascal (Clermont-Ferrand 2) Feb. 17th,
More informationarxiv: v2 [math.co] 11 Oct 2016
ON SUBSEQUENCES OF QUIDDITY CYCLES AND NICHOLS ALGEBRAS arxiv:1610.043v [math.co] 11 Oct 016 M. CUNTZ Abstract. We provide a tool to obtain local descriptions of quiddity cycles. As an application, we
More informationCharacter sheaves and modular generalized Springer correspondence Part 2: The generalized Springer correspondence
Character sheaves and modular generalized Springer correspondence Part 2: The generalized Springer correspondence Anthony Henderson (joint with Pramod Achar, Daniel Juteau, Simon Riche) University of Sydney
More informationIntroduction to cluster algebras. Andrei Zelevinsky (Northeastern University) MSRI/Evans Lecture, UC Berkeley, October 1, 2012
Introduction to cluster algebras Andrei Zelevinsky (Northeastern University) MSRI/Evans Lecture, UC Berkeley, October, 202 http://www.math.neu.edu/zelevinsky/msri-evans-2.pdf Cluster algebras Discovered
More informationPERVERSE SHEAVES ON A TRIANGULATED SPACE
PERVERSE SHEAVES ON A TRIANGULATED SPACE A. POLISHCHUK The goal of this note is to prove that the category of perverse sheaves constructible with respect to a triangulation is Koszul (i.e. equivalent to
More information6. Dynkin quivers, Euclidean quivers, wild quivers.
6 Dynkin quivers, Euclidean quivers, wild quivers This last section is more sketchy, its aim is, on the one hand, to provide a short survey concerning the difference between the Dynkin quivers, the Euclidean
More informationLecture 2: Cluster complexes and their parametrizations
Lecture 2: Cluster complexes and their parametrizations Nathan Reading NC State University Cluster Algebras and Cluster Combinatorics MSRI Summer Graduate Workshop, August 2011 Introduction The exchange
More informationThe Greedy Basis Equals the Theta Basis A Rank Two Haiku
The Greedy Basis Equals the Theta Basis A Rank Two Haiku Man Wai Cheung (UCSD), Mark Gross (Cambridge), Greg Muller (Michigan), Gregg Musiker (University of Minnesota) *, Dylan Rupel (Notre Dame), Salvatore
More informationCombinatorial aspects of derived equivalence
Combinatorial aspects of derived equivalence Sefi Ladkani University of Bonn http://guests.mpim-bonn.mpg.de/sefil/ 1 What is the connection between... 2 The finite dimensional algebras arising from these
More informationAFFINE PUSHFORWARD AND SMOOTH PULLBACK FOR PERVERSE SHEAVES
AFFINE PUSHFORWARD AND SMOOTH PULLBACK FOR PERVERSE SHEAVES YEHAO ZHOU Conventions In this lecture note, a variety means a separated algebraic variety over complex numbers, and sheaves are C-linear. 1.
More informationA course on cluster tilted algebras
Ibrahim Assem Département de mathématiques Université de Sherbrooke Sherbrooke, Québec Canada JK R A course on cluster tilted algebras march 06, mar del plata Contents Introduction 5 Tilting in the cluster
More informationCLUSTER ALGEBRA ALFREDO NÁJERA CHÁVEZ
Séminaire Lotharingien de Combinatoire 69 (203), Article B69d ON THE c-vectors AND g-vectors OF THE MARKOV CLUSTER ALGEBRA ALFREDO NÁJERA CHÁVEZ Abstract. We describe the c-vectors and g-vectors of the
More informationOn the geometric Langlands duality
On the geometric Langlands duality Peter Fiebig Emmy Noether Zentrum Universität Erlangen Nürnberg Schwerpunkttagung Bad Honnef April 2010 Outline This lecture will give an overview on the following topics:
More informationALGEBRAIC MODELS, DUALITY, AND RESONANCE. Alex Suciu. Topology Seminar. MIT March 5, Northeastern University
ALGEBRAIC MODELS, DUALITY, AND RESONANCE Alex Suciu Northeastern University Topology Seminar MIT March 5, 2018 ALEX SUCIU (NORTHEASTERN) MODELS, DUALITY, AND RESONANCE MIT TOPOLOGY SEMINAR 1 / 24 DUALITY
More informationDelzant s Garden. A one-hour tour to symplectic toric geometry
Delzant s Garden A one-hour tour to symplectic toric geometry Tour Guide: Zuoqin Wang Travel Plan: The earth America MIT Main building Math. dept. The moon Toric world Symplectic toric Delzant s theorem
More informationOn root categories of finite-dimensional algebras
On root categories of finite-dimensional algebras Changjian Department of Mathematics, Sichuan University Chengdu August 2012, Bielefeld Ringel-Hall algebra for finitary abelian catgories Ringel-Hall Lie
More informationQuivers of Period 2. Mariya Sardarli Max Wimberley Heyi Zhu. November 26, 2014
Quivers of Period 2 Mariya Sardarli Max Wimberley Heyi Zhu ovember 26, 2014 Abstract A quiver with vertices labeled from 1,..., n is said to have period 2 if the quiver obtained by mutating at 1 and then
More informationHochschild and cyclic homology of a family of Auslander algebras
Hochschild and cyclic homology of a family of Auslander algebras Rachel Taillefer Abstract In this paper, we compute the Hochschild and cyclic homologies of the Auslander algebras of the Taft algebras
More informationCluster algebras of infinite rank
J. London Math. Soc. (2) 89 (2014) 337 363 C 2014 London Mathematical Society doi:10.1112/jlms/jdt064 Cluster algebras of infinite rank Jan E. Grabowski and Sira Gratz with an appendix by Michael Groechenig
More informationCombinatorics of Theta Bases of Cluster Algebras
Combinatorics of Theta Bases of Cluster Algebras Li Li (Oakland U), joint with Kyungyong Lee (University of Nebraska Lincoln/KIAS) and Ba Nguyen (Wayne State U) Jan 22 24, 2016 What is a Cluster Algebra?
More informationLECTURE 16: REPRESENTATIONS OF QUIVERS
LECTURE 6: REPRESENTATIONS OF QUIVERS IVAN LOSEV Introduction Now we proceed to study representations of quivers. We start by recalling some basic definitions and constructions such as the path algebra
More informationAn overview of D-modules: holonomic D-modules, b-functions, and V -filtrations
An overview of D-modules: holonomic D-modules, b-functions, and V -filtrations Mircea Mustaţă University of Michigan Mainz July 9, 2018 Mircea Mustaţă () An overview of D-modules Mainz July 9, 2018 1 The
More informationTRIVIAL MAXIMAL 1-ORTHOGONAL SUBCATEGORIES FOR AUSLANDER 1-GORENSTEIN ALGEBRAS
J. Aust. Math. Soc. 94 (2013), 133 144 doi:10.1017/s1446788712000420 TRIVIAL MAXIMAL 1-ORTHOGONAL SUBCATEGORIES FOR AUSLANDER 1-GORENSTEIN ALGEBRAS ZHAOYONG HUANG and XIAOJIN ZHANG (Received 25 February
More informationUNIVERSAL DERIVED EQUIVALENCES OF POSETS
UNIVERSAL DERIVED EQUIVALENCES OF POSETS SEFI LADKANI Abstract. By using only combinatorial data on two posets X and Y, we construct a set of so-called formulas. A formula produces simultaneously, for
More informationWIDE SUBCATEGORIES OF d-cluster TILTING SUBCATEGORIES
WIDE SUBCATEGORIES OF d-cluster TILTING SUBCATEGORIES MARTIN HERSCHEND, PETER JØRGENSEN, AND LAERTIS VASO Abstract. A subcategory of an abelian category is wide if it is closed under sums, summands, kernels,
More informationAlgebraic Geometry Spring 2009
MIT OpenCourseWare http://ocw.mit.edu 18.726 Algebraic Geometry Spring 2009 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. 18.726: Algebraic Geometry
More informationEKT of Some Wonderful Compactifications
EKT of Some Wonderful Compactifications and recent results on Complete Quadrics. (Based on joint works with Soumya Banerjee and Michael Joyce) Mahir Bilen Can April 16, 2016 Mahir Bilen Can EKT of Some
More informationThe Diamond Category of a Locally Discrete Ordered Set.
The Diamond Category of a Locally Discrete Ordered Set Claus Michael Ringel Let k be a field Let I be a ordered set (what we call an ordered set is sometimes also said to be a totally ordered set or a
More informationTOPOLOGY OF LINE ARRANGEMENTS. Alex Suciu. Northeastern University. Workshop on Configuration Spaces Il Palazzone di Cortona September 1, 2014
TOPOLOGY OF LINE ARRANGEMENTS Alex Suciu Northeastern University Workshop on Configuration Spaces Il Palazzone di Cortona September 1, 2014 ALEX SUCIU (NORTHEASTERN) TOPOLOGY OF LINE ARRANGEMENTS CORTONA,
More informationMATH 433 Applied Algebra Lecture 21: Linear codes (continued). Classification of groups.
MATH 433 Applied Algebra Lecture 21: Linear codes (continued). Classification of groups. Binary codes Let us assume that a message to be transmitted is in binary form. That is, it is a word in the alphabet
More informationDirect Limits. Mathematics 683, Fall 2013
Direct Limits Mathematics 683, Fall 2013 In this note we define direct limits and prove their basic properties. This notion is important in various places in algebra. In particular, in algebraic geometry
More informationOrbit closures of quiver representations
Orbit closures of quiver representations Kavita Sutar Chennai Mathematical Institute September 5, 2012 Outline 1 Orbit closures 2 Geometric technique 3 Calculations 4 Results Quiver Q = (Q 0, Q 1 ) is
More informationProblem 1. Let f n (x, y), n Z, be the sequence of rational functions in two variables x and y given by the initial conditions.
18.217 Problem Set (due Monday, December 03, 2018) Solve as many problems as you want. Turn in your favorite solutions. You can also solve and turn any other claims that were given in class without proofs,
More informationTHE CLASSIFICATION PROBLEM REPRESENTATION-FINITE, TAME AND WILD QUIVERS
October 28, 2009 THE CLASSIFICATION PROBLEM REPRESENTATION-FINITE, TAME AND WILD QUIVERS Sabrina Gross, Robert Schaefer In the first part of this week s session of the seminar on Cluster Algebras by Prof.
More informationThe real root modules for some quivers.
SS 2006 Selected Topics CMR The real root modules for some quivers Claus Michael Ringel Let Q be a finite quiver with veretx set I and let Λ = kq be its path algebra The quivers we are interested in will
More informationDESINGULARIZATION OF QUIVER GRASSMANNIANS FOR DYNKIN QUIVERS. Keywords: Quiver Grassmannians, desingularizations.
DESINGULARIZATION OF QUIVER GRASSMANNIANS FOR DYNKIN QUIVERS G. CERULLI IRELLI, E. FEIGIN, M. REINEKE Abstract. A desingularization of arbitrary quiver Grassmannians for representations of Dynkin quivers
More information16.2. Definition. Let N be the set of all nilpotent elements in g. Define N
74 16. Lecture 16: Springer Representations 16.1. The flag manifold. Let G = SL n (C). It acts transitively on the set F of complete flags 0 F 1 F n 1 C n and the stabilizer of the standard flag is the
More informationDerived equivalence classification of the cluster-tilted algebras of Dynkin type E
Derived equivalence classification of the cluster-tilted algebras of Dynkin type E Janine Bastian, Thorsten Holm, and Sefi Ladkani 2 Leibniz Universität Hannover, Institut für Algebra, Zahlentheorie und
More informationarxiv: v1 [math.rt] 20 Dec 2018
MINUSCULE REVERSE PLANE PARTITIONS VIA QUIVER REPRESENTATIONS ALEXANDER GARVER, REBECCA PATRIAS, AND HUGH THOMAS arxiv:181.845v1 [math.rt] Dec 18 Abstract. A nilpotent endomorphism of a quiver representation
More informationModuli spaces of sheaves and the boson-fermion correspondence
Moduli spaces of sheaves and the boson-fermion correspondence Alistair Savage (alistair.savage@uottawa.ca) Department of Mathematics and Statistics University of Ottawa Joint work with Anthony Licata (Stanford/MPI)
More informationThe Riemann Roch theorem for metric graphs
The Riemann Roch theorem for metric graphs R. van Dobben de Bruyn 1 Preface These are the notes of a talk I gave at the graduate student algebraic geometry seminar at Columbia University. I present a short
More informationLINEAR ALGEBRA BOOT CAMP WEEK 1: THE BASICS
LINEAR ALGEBRA BOOT CAMP WEEK 1: THE BASICS Unless otherwise stated, all vector spaces in this worksheet are finite dimensional and the scalar field F has characteristic zero. The following are facts (in
More informationSOLVABLE FUSION CATEGORIES AND A CATEGORICAL BURNSIDE S THEOREM
SOLVABLE FUSION CATEGORIES AND A CATEGORICAL BURNSIDE S THEOREM PAVEL ETINGOF The goal of this talk is to explain the classical representation-theoretic proof of Burnside s theorem in finite group theory,
More informationCoherent sheaves on elliptic curves.
Coherent sheaves on elliptic curves. Aleksei Pakharev April 5, 2017 Abstract We describe the abelian category of coherent sheaves on an elliptic curve, and construct an action of a central extension of
More informationEpilogue: Quivers. Gabriel s Theorem
Epilogue: Quivers Gabriel s Theorem A figure consisting of several points connected by edges is called a graph. More precisely, a graph is a purely combinatorial object, which is considered given, if a
More informationGeneralized Alexander duality and applications. Osaka Journal of Mathematics. 38(2) P.469-P.485
Title Generalized Alexander duality and applications Author(s) Romer, Tim Citation Osaka Journal of Mathematics. 38(2) P.469-P.485 Issue Date 2001-06 Text Version publisher URL https://doi.org/10.18910/4757
More informationThus we get. ρj. Nρj i = δ D(i),j.
1.51. The distinguished invertible object. Let C be a finite tensor category with classes of simple objects labeled by a set I. Since duals to projective objects are projective, we can define a map D :
More informationTorus Knots and q, t-catalan Numbers
Torus Knots and q, t-catalan Numbers Eugene Gorsky Stony Brook University Simons Center For Geometry and Physics April 11, 2012 Outline q, t-catalan numbers Compactified Jacobians Arc spaces on singular
More informationRELATIVE THEORY IN SUBCATEGORIES. Introduction
RELATIVE THEORY IN SUBCATEGORIES SOUD KHALIFA MOHAMMED Abstract. We generalize the relative (co)tilting theory of Auslander- Solberg [9, 1] in the category mod Λ of finitely generated left modules over
More informationMATH 101: ALGEBRA I WORKSHEET, DAY #1. We review the prerequisites for the course in set theory and beginning a first pass on group. 1.
MATH 101: ALGEBRA I WORKSHEET, DAY #1 We review the prerequisites for the course in set theory and beginning a first pass on group theory. Fill in the blanks as we go along. 1. Sets A set is a collection
More informationarxiv: v1 [math.rt] 15 Oct 2008
CLASSIFICATION OF FINITE-GROWTH GENERAL KAC-MOODY SUPERALGEBRAS arxiv:0810.2637v1 [math.rt] 15 Oct 2008 CRYSTAL HOYT AND VERA SERGANOVA Abstract. A contragredient Lie superalgebra is a superalgebra defined
More informationQuiver Representations and Gabriel s Theorem
Quiver Representations and Gabriel s Theorem Kristin Webster May 16, 2005 1 Introduction This talk is based on the 1973 article by Berstein, Gelfand and Ponomarev entitled Coxeter Functors and Gabriel
More informationTHE GL(2, C) MCKAY CORRESPONDENCE
THE GL(2, C) MCKAY CORRESPONDENCE MICHAEL WEMYSS Abstract. In this paper we show that for any affine complete rational surface singularity the quiver of the reconstruction algebra can be determined combinatorially
More informationQUIVER GRASSMANNIANS, QUIVER VARIETIES AND THE PREPROJECTIVE ALGEBRA
QUIVER GRASSMANNIANS, QUIVER VARIETIES AND THE PREPROJECTIVE ALGEBRA ALISTAIR SAVAGE AND PETER TINGLEY Abstract. Quivers play an important role in the representation theory of algebras, with a key ingredient
More informationA visual introduction to Tilting
A visual introduction to Tilting Jorge Vitória University of Verona http://profs.sci.univr.it/ jvitoria/ Padova, May 21, 2014 Jorge Vitória (University of Verona) A visual introduction to Tilting Padova,
More informationNoetherian property of infinite EI categories
Noetherian property of infinite EI categories Wee Liang Gan and Liping Li Abstract. It is known that finitely generated FI-modules over a field of characteristic 0 are Noetherian. We generalize this result
More informationFinite representation type
Finite representation type Stefan Wolf Dynkin and Euclidean diagrams Throughout the following section let Q be a quiver and Γ be its underlying graph.. Notations Some Notation: (α, β) := α, β + β, α q
More informationRepresentations of algebraic groups and their Lie algebras Jens Carsten Jantzen Lecture III
Representations of algebraic groups and their Lie algebras Jens Carsten Jantzen Lecture III Lie algebras. Let K be again an algebraically closed field. For the moment let G be an arbitrary algebraic group
More informationCALABI-YAU ALGEBRAS AND PERVERSE MORITA EQUIVALENCES
CALABI-YAU ALGEBRAS AND PERERSE MORITA EQUIALENCES JOSEPH CHUANG AND RAPHAËL ROUQUIER Preliminary Draft Contents 1. Notations 2 2. Tilting 2 2.1. t-structures and filtered categories 2 2.1.1. t-structures
More informationReducibility of generic unipotent standard modules
Journal of Lie Theory Volume?? (??)???? c?? Heldermann Verlag 1 Version of March 10, 011 Reducibility of generic unipotent standard modules Dan Barbasch and Dan Ciubotaru Abstract. Using Lusztig s geometric
More informationValued Graphs and the Representation Theory of Lie Algebras
Axioms 2012, 1, 111-148; doi:10.3390/axioms1020111 Article OPEN ACCESS axioms ISSN 2075-1680 www.mdpi.com/journal/axioms Valued Graphs and the Representation Theory of Lie Algebras Joel Lemay Department
More informationSELF-DUAL HOPF QUIVERS
Communications in Algebra, 33: 4505 4514, 2005 Copyright Taylor & Francis, Inc. ISSN: 0092-7872 print/1532-4125 online DOI: 10.1080/00927870500274846 SELF-DUAL HOPF QUIVERS Hua-Lin Huang Department of
More informationCHARACTER SHEAVES ON UNIPOTENT GROUPS IN CHARACTERISTIC p > 0. Mitya Boyarchenko Vladimir Drinfeld. University of Chicago
arxiv:1301.0025v1 [math.rt] 31 Dec 2012 CHARACTER SHEAVES ON UNIPOTENT GROUPS IN CHARACTERISTIC p > 0 Mitya Boyarchenko Vladimir Drinfeld University of Chicago Overview These are slides for a talk given
More informationThe Hurewicz Theorem
The Hurewicz Theorem April 5, 011 1 Introduction The fundamental group and homology groups both give extremely useful information, particularly about path-connected spaces. Both can be considered as functors,
More informationUpper triangular matrices and Billiard Arrays
Linear Algebra and its Applications 493 (2016) 508 536 Contents lists available at ScienceDirect Linear Algebra and its Applications www.elsevier.com/locate/laa Upper triangular matrices and Billiard Arrays
More informationSPECIALIZATION ORDERS ON ATOM SPECTRA OF GROTHENDIECK CATEGORIES
SPECIALIZATION ORDERS ON ATOM SPECTRA OF GROTHENDIECK CATEGORIES RYO KANDA Abstract. This report is a survey of our result in [Kan13]. We introduce systematic methods to construct Grothendieck categories
More informationFILTERED RINGS AND MODULES. GRADINGS AND COMPLETIONS.
FILTERED RINGS AND MODULES. GRADINGS AND COMPLETIONS. Let A be a ring, for simplicity assumed commutative. A filtering, or filtration, of an A module M means a descending sequence of submodules M = M 0
More informationMutation classes of quivers with constant number of arrows and derived equivalences
Mutation classes of quivers with constant number of arrows and derived equivalences Sefi Ladkani University of Bonn http://www.math.uni-bonn.de/people/sefil/ 1 Motivation The BGP reflection is an operation
More informationCritical level representations of affine Kac Moody algebras
Critical level representations of affine Kac Moody algebras Peter Fiebig Emmy Noether Zentrum Universität Erlangen Nürnberg Isle of Skye May 2010 Affine Kac Moody algebras Let g be a complex simple Lie
More informationGenerators of affine W-algebras
1 Generators of affine W-algebras Alexander Molev University of Sydney 2 The W-algebras first appeared as certain symmetry algebras in conformal field theory. 2 The W-algebras first appeared as certain
More informationInvolutions of the Symmetric Group and Congruence B-Orbits (Extended Abstract)
FPSAC 010, San Francisco, USA DMTCS proc. AN, 010, 353 364 Involutions of the Symmetric Group and Congruence B-Orbits (Extended Abstract) Eli Bagno 1 and Yonah Cherniavsky 1 Jerusalem College of Technology,
More informationHARTSHORNE EXERCISES
HARTSHORNE EXERCISES J. WARNER Hartshorne, Exercise I.5.6. Blowing Up Curve Singularities (a) Let Y be the cusp x 3 = y 2 + x 4 + y 4 or the node xy = x 6 + y 6. Show that the curve Ỹ obtained by blowing
More informationGroups, Group rings and the Yang-Baxter equation. International Workshop Groups, Rings, Lie and Hopf Algebras.III
Groups, Group rings and the Yang-Baxter equation International Workshop Groups, Rings, Lie and Hopf Algebras.III August 12 18, 2012 Bonne Bay Marine Station Memorial University of Newfoundland Eric Jespers
More information