Claus Michael Ringel

Lectures

Fully documented Lectures

• The Birkhoff problem: How to classify subgroups of finite abelian groups?
  Lecture Oxford, 28.02.2003 (Hilary Term Colloqium).
• Algebra or Algebras Are there many kinds of algebras?
  Trondheim Lecture, May 27, 2004.
• The Hall multiplication.
  Oxford Lecture, March 3, 2006.
  In honour of the 80th birthday of Sandy Green
• Algebra ist Geometrie ist Algebra.
  Paderborn, 10.11.2006,
  Conference in Homour of Helmut Lenzing.
• Tilting Theory: The Art of Losing Modules.
  Padua, March 16, 2007.
  (Celebrating the 20th Anniversary of the Department of Pure and Applied Mathematics).
• The relevance and the ubiquity of Prüfer modules
  Presentation (Torun, August 2007)
• Hiroyuki Tachikawa and the development of the representation theory of finite dimensional algebras
  (Tokyo, Sept. 2007)
• Some minimal representation-infinite semigroups
  Presentation (St.Petersburg, Sept.2007)
• Invariant Subspaces of Nilpotent Linear Operators
  Berlin Mathematical School, 23. November 2007
• Root systems and canonical algebras
  Newton-Institute, Cambridge, 16.03.2009
  Flash Video
• Why are canonical algebras canonical?
  Paderborn, Feb 12, 2009, Shanghai, Oct 1, 2009.
• Nakayama algebras of Loewy length 3
  Paderborn, May 30, 2009.
  Shanghai-Version (Oct 6, 2009)
  Workshop: Triangulated Categories and Singularities (May 26 - 30, 2009)
• The representation theory of cluster-concealed algebras
  Leicester
  Workshop on Derived Categories in Algebra, Topology and Geometry (17th to 19th September 2009)
  Video recordings

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• Diskrete ebene Bewegungsgruppen
  Vorlesung am Informationstag 30.01.03, für Schülerinnen und Schüler der 12. und 13. Jahrgangsstufe.
  (Hier als Auszug die Liste der Materialien)
• Naturwissenschaftliche Kenntnisse? "... zur Bildung gehören sie nicht!"
  Zur Einweihung des Biotech-Labors am Engelbert-Kaempfer-Gymnasium in Lemgo, 23. Oktober 2006. Text
• Zum Mathematiker werden - in nur 20 Minuten!
  Eröffnung der Ausstellung Mathematik zum Anfassen, Salzuflen 27.08.2006, 14:00.
• Spiegelungen
  Festvortrag zur Emeritierung von Hartmut Spiegel
  Paderborn, 30.05.2009,     Zwei Euklid-Dateien: abstand.geo,     insel.geo

• Was besagt schon ein einzelner Zahlenwert?
  Zur Bedeutung des funktionalen Denkens.
  Paderborn, 10.09.2009.
  Hier eine Ausarbeitung eines Vortrags von Christoph Richard mit dem Titel The Newcomb-Benford Law: Theory and Applications.
  Er wies mich darauf hin, dass man für die "d65"-Wahrscheinlicheiten nicht die wirklichen NB-Werte log₁₀(1+1/d) erhält, selbst dann nicht, wenn man es mit NB-Zufallsvariablen zu tun hat. Diese bedingten Wahrscheinlichkeiten können mit den Formeln auf seiner Folie 15 unschwer berechnet werden (sie ähneln zwar den NB-erten), sind aber komplizierter zu beschreiben).

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• The role of the natural numbers and the real numbers in Whitehead's cosmology.
  (On Kronecker's dictum: "God made the natural numbers; all else is the work of man.")
  Salzburg, 04.07.2006.

Further List

2016

• 4.2.2016, 15:00. Mathematik-Olympiade Gütersloh: Das Fotoautomaten-Paradox
• Shanghai Feb 24 - March 24.
  SJTU. Lectures on representations of quivers. Dynkin quivers, Euclidean quivers, Kronecker quivers.
  • Hefei, Anhui University, March 7
  • Nantong University, March 18.
• Bonn June 17, 12:00
  Lecture: The Root Posets and Hammocks
• Uppsala, Sept 15, 2016, 10:15
  Lecture: The representation theory of Dynkin quivers and the Freudenthal-Tits magic square
  Text
• Isfahan Oct 14 - 28.
  Two days seminar: 19 and 20 October.
  The n-Kronecker modules
• Shanghai Nov 7 - Dez 8.
  • Seminar lectures: Combinatorial aspects of the representation theory of quivers. Abstract
  • Colloquium lecture (Nov 11): The elementary representations of the 3-Kronecker quiver. Abstract
  • Hangzhou lecture: The Root Posets and Hammocks Abstract
  • Beijing lecture (Nov. 25): The representation theory of Dynkin quivers and the Freudenthal-Tits magic square. Abstract
    Text
  • Hefei lecture: The Kronecker modules Abstract
• Algebra workshop at University of Bucharest, Dec. 10, 2016.
  The representation theory of Dynkin quivers and the Freudenthal-Tits magic square.

2015

• Feb 14 - March 15, 2015. "Representation Theory" Spring 2015 (Feb 9 - May 22) at the Mittag-Leffler Institute (organizers: Henning Andersen, Aslak Buan, Walter Mazorchuk)
  Introductory Workshop, 25 Feb - 01 March 2015, Uppsala University, Uppsala.
  Lecture: Non-crossing partitions and parking functions: categorification using quiver representations
• April 23 - 28, 2015: UConn
  International Conference on Representation Theory and Commutative Algebra
  A conference in honor of Jerzy Weyman's 60th Birthday, April 24-April 27 at the University of Connecticut
  Lecture: The submodules of length 2: a first encounter of representation theory and algebraic geometry.
  Abstract
• May 13 Rome
  Lecture: Representations of quivers over the algebra of dual numbers
  Abstract
• Shanghai SJTU June 28 - Aug 2, 2015
  The submodules of length 2
  Lecture series: Representation theory of quivers and algebras
  
• Hangzhou, July 1-7.
  Lecture: The submodules of length 2
• August 10-12, Hyperplane Arrangements and Reflection Groups, Hannover
  Lecture: Catalan combinatorics and representation theory
  Abstract
• Shizuoka University, 11-12 September: Derived categories of finite dimensional algebras. Conference honoring Hideto Asashiba on the occasion of his 60th birthday
  Lecture: Hereditary triangulated categories. Abstract
• Nagoya, 14 Sept Abstract
• Shanghai SJTU Sept 15 - Oct 15, 2015
  Selected topics in representation theory
• Xiamen Sept 28, 2015
  Bristly modules
• Workshop Southeast University, Nanjing, Oct 9-10, 2015.
  

2014

• KAU, Jeddah. Jan 13 - Feb 3.
  Lectures on the Ingalls-Thomas bijection.
• Oberwolfach: Representation Theory of Quivers and Finite Dimensional Algebras, 16.-22.02.2014
  Lecture: Auslander varieties for wild finite-dimensional algebras
  Extended Abstract
• March 1-29. SJTU.
  Lecture: The Auslander varieties
  Abstract
• Oberwolfach May 18-24
• Bielefeld, June 12-14. Workshop on non-crossing partitions.
  Lecture: Crossing and nesting
  Abstract
• Turkey:
  • Lecture: Hidden symmetries of the root systems, Yeditepe University, June 19, 2014
    3rd Rings, Modules and Algebras Workshop
  • Lecture series: Introductory course on Representations Theory of Finite Dimensional Algebras. June 23-27, 2014. I.Y.T.E., Izmir.
    June 23-27, 2014, Izmir, Turkey
• Shanghai: August 10 - Sept 13.
  ICRA 2014: International Conference on Representations of Algebras, Sanya, Hainan Province, China.
  Workshop: August 20-23, 2014 (We-Sa);
  Series of lectures: The root posets
  Conference: August 25-29, 2014 (Mo-Fr).
  Lecture: The Auslander varieties.
  Lecture Series: Non-crossing partitions. SJTU, Sept. 5 and 8, 2014.
  Lecture: Shanghai University, Sept 10, 2014 Abstract
• Semester on Representation Theory at the University of Connecticut.
  Three lectures, Oct 13, 15, 16, 2014.
  Abstracts
  • The Brauer-Thrall conjectures
  • Representations of directed quivers over the algebra of dual numbers
  • Wild algebras
• October 20: Lecture at the GASC seminar at Northeastern.
  The Auslander varieties for a wild algebra
• Murcia conference Categorical methods in Rings and Modules
  Non-crossing partitions and parking functions: categorification using quiver representations

2013

• 10.1.2013. Oberseminar Lie-Theorie Paderborn:
  Einführung in die Darstellungstheorie der Köcher.
• 18.01.2013 Birep-Seminar
  From submodule categories to preprojective algebras
  Abstract
• 01.02.-20.02.2013. KAU Jeddah
  • Lecture Series (Feb 3,5, 10, 12, 17, 19): The Auslander bijections: How morphism are determined by modules
• 12.04.2013, Bielefeld. Workshop Non-Crossing Partitions.
  The non-crossing partitions for any Dynkin type are the antichains in the corresponding root poset. On antichains in posets and in additive categories.
• USA, April 16 - 29, 2013.
  • Maurice Auslander Distinguished Lectures and International Conference
    Woods Hole Oceanographic Institute, Woods Hole, MA, USA.
    April 18-23, 2013.
    Lecture: The Auslander bijections
    Presentation
  • Algebra, Combinatorics and Representation Theory, conference on the occasion of the 60th birthday of Andrei Zelevinsky.
    April 24-28, 2013, Northeastern University in Boston.
    Lecture: Ubiquity and universality of quiver Grassmannians
    Presentation
• Chemnitz, 3-4 May 2013: Conference in memoriam of Dieter Happel
  Lecture: The early years of tilting theory. 1980-1985.
• SJTU Shanghai, May 22 - June 29, 2013.
  • Workshop USTC Hefei, May 25-26, 2013
    Lecture: The Gorenstein projective modules for the Nakayama algebras.
    Abstract
  • Colloquium SJTU June 4, 2013.
    The hidden symmetries of root systems
    Abstract
  • The Third Symposium on Groups, Algebras and Related Topics, Beijing University, June 10 - 16.
    Lecture: Categorification of non-crossing partitions: Crossing and Nesting.
    Abstract
  • International Conference on Representation Theory (ICRT-VI), organized by Hunan Normal University,
    June 18 to 23, 2013 in Zhangjiajie, Hunan Province,
    Lecture: The Auslander bijections
    Abstract
  • 2^nd PRIMA Congress (PRIMA = Pacific Rim Mathematical Association)
    June 24-28, 2013 Shanghai Jiaotong University Shanghai, China,
    organised by the Pacific Institute for the Mathematical Sciences.
    Special session: Triangulated categories in representation theory of algebras.
    (Organizers: Ragnar Buchweitz, Shiping Liu, Claus Michael Ringel, Pu Zhang.)
    Lecture: From submodule categories to preprojective algebras
    Abstract
    
• Advances in Representation Theory of Algebras (ARTA), September 9-13, 2013, Torun, Poland
  The root posets (and the hereditary abelian categories of Dynkin type)
  Abstract
• Australia
  • Australian Mathematical Society 57th Annual Meeting, Sydney, Sept 30 - Oct 3 2013.
    Lecture: Hidden symmetries of root systems
    Abstract
    Presentation (or Presentation)
  • AMSI National Access Grid Seminar Series, Friday, Sept. 27, 2013.
    Lecture: Fibonacci numbers and Linear Algebra.
    Abstract
  • Behrend Memorial lecture, Department of Mathematics and Statistics at Melbourne. Monday, Sept. 14, 2013.
    Lecture: Linked Circles. Geometry - Topology - Algebra.
    Abstract
  • University of Melbourne, Sept 14, 2013, 11:00: The Auslander bijections
• Bristol Leicester Oxford Colloquium. Special BLOC Meeting Oct 17-18, 2013, Mathematical Institute, 24-29 St Giles, Oxford.
  The root posets (and the hereditary abelian categories of Dynkin type)
• Perspectives of Representation Theory of Algebras - Conference honoring Kunio Yamagata on the occasion of his 65th birthday
  Nagoya University, 11-15 November 2013 (travel days 10 and 16).

2012

• King Abdulaziz University (KUA) Jeddah
  Course: Introduction to the representation theory of quivers. link
  13.02.-09.03.2012.
• Cluster categories and cluster tilting
  A conference honoring Idun Reiten on the occasion of her 70th birthday
  March 28 - 30, 2012, Trondheim, Norway
  Abelian categories versus triangulated categories: Some examples. Abstract, Presentation
• Bielefeld, April 13, 2012, 14:15: Morphisms determined by objects: The case of modules over artin algebras
• China. SJTU: May 29 - June 30, 2012.
  • June 21, 22: USTC, Hefei. Lectures: How modules over artin algebras determine morphisms.   Abstract
  • June 22 - 26: University of Anhui, Hefei: National workshop on representation theory of algebras.
    Lecture: Tree modules   Abstract
• ICRA Bielefeld. Workshop: 8.-11.08., Conference 13.-17.8.2012
  How modules determine morphisms: The Auslander bijections as a frame for the representation theory of artin algebras. Abstract
• China: SJTU: Oct 4 - Nov 6 2012.
  • East China Algebra Conference, Oct.12-14, 2012, ECNU, Shanghai
    Tubular triangulated categories
  • Yangzhou workshop on Hopf algebra, Oct 20
    Gorenstein projectives for Nakayama algebras
  • SJTU, Oct 10, 16:00. Why are the canonical algebras canonical?
  • Lecture series: Gorenstein projectives for Nakayama algebras. (SJTU)
    From subspace categories to preprojective algebras (SJTU)
• Lecture Sherbrooke, Nov 12.
  Distinguished bases of exceptional modules

2011

• Bonn: Jan-April 2011.
  Winterschool 10.-14.Jan 2011
  The indecomposable representations of a finite quiver (3 lectures)
  Workshop March 28 - April 1.
• OW: 20.-26.02.2011. Representation Theory of Quivers and Finite Dimensional Algebras
  Lecture: Some Auslander-Reiten quilts
  Abstract
• Darstellungstheorie Schwerpunkttagung 2011
  In 10 minutes: What is a hereditary algebra? (Ext^2 and the vanishing of Ext^2).
• Trondheim, May 11-18, 2011.
  Lecture: Cluster-additive functions on stable translation quivers, 12.05.2011
  • Some examples
  • On hammocks (click on the pictures to continue)
  • The paper
• Abel Symposium: Algebras, Quivers, and Representations
  June 20-23, 2011, Sognerfjord.
  Lecture: Tensor Products of Path Algebras
  See part II of On the representation dimension of an artin algebra
• MARTa, Herford, 15.09.2011:
  Buckminster Fuller. Mathematische Grundlagen: Kugeln und Polyeder,
  im Rahmen eines Workshops: Raumforschen im RB Fuller-Satelliten von Silke Riechert
• Banff:
  25.-30.9.2011 Almost periodic order: spectral, dynamical, and stochastic approaches
  Lecture: Fibonacci numbers and representations of quivers
  Abstract   Video: Part 1, Part 2.
• China: October - November 2011
  • Shanghai Conference (SJTU) October 2 - 6, 2011
    Lecture: Fibonacci numbers and representations of quivers
    Slides
  • SJTU lectures: October, November 2011.
  • Nanjing University, October 29, 2011: Modules determined by morphisms.
  • East China Normal University, November 12-13, 2011: Representations of a quiver over the ring of dual numbers.
  • SJTU, November 17, 2011: The Gorenstein-projective modules for some special biserial algebras
  • Nanjing Normal University, November 25, 2011: Some examples of Gorenstein-projective modules

2010

• Gießen: Mathematikum 15.01.2010
  Unmöglich - oder doch möglich? Denkspiele und Puzzles, die die Köpfe rauchen lassen!
  Präsentation

• MNU-Tagung Bielefeld, 28.3.-1.4.2010

• Eleganz in der Mathematik. Kunsthalle Bielefeld, 30. April 2010. Präsentation

• Interplay between Representation Theory and Geometry
  Beijing, May 3 - 7, 2010:
  The set of lengths of indecomposables has no gaps
• Oberwolfach, May 9 - 15, 2010
  Torsion pairs and vectorspace categories
  Abstract
• St.Petersburg, June 19 - 24, 2010.
  Minimal representation-infinite algebras.
• ICRA XIV Tokyo, August 6 - 15, 2010
  Lecture series in the workshop: Minimal representation-infinite algebras.
• Banff: September 12 - 17, 2010.
  Test Problems for the theory of finite dimensional algebras
  What is known about invariant subspaces of nilpotent operators? Survey. I
  The cases n ≤ 6 (pdf-file)
  General considerations (html)
  Part II of the survey was given by Markus Schmidmeier and is not (yet) available.

• Shanghai, Oct-Nov. 2010
  • Shanghai: Invariant subspaces
  • Shanghai: Min rep-inf algebras
  • Nanjing: Cluster concealed algebras
  • A Categorification of the Fibonacci Numbers Using Representations of Quivers
        Fibonacci numbers
  • Representations of Quivers: First Steps (Shanghai JiaoTong University, 2010)

• Mathematikdidaktisches Kolloquium Bielefeld, 7.12.2010, 18:00, H 10

  Eleganz in der Mathematik: Verkettete Kreise im Raum Ankündigung Präsentation

• Torun, December 13-15, 2010.
• Taiwan, Dec 18-23, 2010.

2009

• Cluster-concealed algebras
  Trondheim
  Homological and geometric methods in algebra (10.-14.08.2009) (10.-14.08.2009)
• Foundations of the representation theory theory of artin algebras
  6 lectures, Bremen, August 16, 17, 19, 2009.
  Summer School: Structures in Lie Representation Theory
• September/October 2009: Shanghai Lectures
  • Nakayama algebras of Loewy length 3.
  • Why are the canonical algebras canonical?
  • Cluster concealed algebras

2008

• Oberwolfach.
  An introduction to the representation dimension of artin algebras
  Extended abstract
• Shanghai: Jiao Tong University, East China Normal University.
  The representation dimension of an artin algebra.

2007

• Perspectives in Auslander-Reiten Theory (On the occasion of the 65th birthday of Idun Reiten)
  Some minimal representation-infinite algebras.
  Trondheim 10.-12.05.2007.
• Second Internation Congress on Algebra and Combinatorics, Xian University of architectural Technology and Science, Xian, July 11-14, 2007.
  Minimal representation-infinite semigroups
• The 4th International Conference on Representation Theory
  Lhasa, Tibet, 16.-20.07.2007
• XII International Conference on Representations of Algebras and Workshop.
  ICRA, Torun 15.-24.08.2007
• Shanghai: Jiao Tong University: Pruefer modules
  Nanjing: Tilting modules and tilted algebras
  Nanjing Normal University: The Gabriel-Roiter measure and the first Brauer-Thrall conjecture

2006

• 23.-28.01.06 Trieste: ICTP. Conference "Representation Theory"
  The Bo Chen theorem and Hall polynomials.
• 02.-06.02.06 Münster. Conference: "Noncommutative algebras-"
  Tilted algebras and cluster tilted algebras. (05.02.)
• 05.-31.03.06 Mar del Plata:
  Degenerations of modules and the construction of generic modules.
  Bahia Blanca (Agentina): Foundation of the representation theory of artin algebras.
  
• 07.-13.05.06 Oberwolfach. "Interactions between Algebraic Geometry and Noncommutative Algebra".
  Degenerations of modules and the construction of Prüfer modules
  Extended abstract
• 09.06.2006 Münster: 5. Symposion of the SFB
  The Brauer-Thrall conjectures
• June 15-20 Antwerp
• September 06: Morningside Center, Beijing.
• September 06: Bonn. DMV-Tagung. Special session.
• 20.-24.11.06 Luminy: Hall algebras
• Naturwissenschaftliche Kenntnisse? "... zur Bildung gehören sie nicht!"
  Zur Einweihung des Biotech-Labors am Engelbert-Kaempfer-Gymnasium in Lemgo, 23. Oktober 2006.
  Text

2005

• March 11, 2005. Jiao-Tong-University, Shanghai:
  Subgroups of finite abelian groups.
• March 16, 20, 23: Vortragsreihe. CMS, Zhejiang University, Hangzhou:
  Foundation of the representation theory of artin algebras.
• March 24: USTC-SIS Shanghai.
  The representation dimension of an artin algebra
• March 25: ECNU, Shanghai.
  Gabriel-Roiter measure (for representation finite algebras)
• May: BNU + Chinese-German Center
• August: Qinghua
• November: International University Bremen
• November: Kopenhagen
• Bielefeld, Seminar: Rhombal algebras

2004

• February 17, 2004. Mittag-Leffler-Institut Stockholm
  Subgroups of finite abelian groups.
• March 15, 2004, Algebra and Geometry Seminar, Uppsala
  Subgroups of finite abelian groups.
• March 18, 2004. Mittag-Leffler-Institut Stockholm
  The Gabriel-Roiter measure.
• May 28, 2004, Trondheim
• June 23-26 Conference: Representation Theory and Applications. Uppsala
  The Gabriel-Roiter measure.
• August 11-20, ICRA XI, Mexico.
  The Gabriel-Roiter measure.
• Sherbrooke: Math-Club
• Sherbrooke Subgroups of finite abelian groups/a>
• Boston: Kolloquium
  The Birkhoff problem: How to classify subgroups of finite abelian groups?
• Boston: Auslander and the The Brauer-Thrall conjectures
• November 26-28: Uppsala, Tame and Wild, for Drozd.
• Puzzle-Vortrag: Geraden - Staebe - Puzzles
  (Staebe: Geraden-Konfigurationen im Raum)

2003

• July 14 - 18, 2003, Lisboa, Portugal
  International Conference on Algebras, Modules and Rings
  Basic properties of the module category of an artin algebra.
• July 20 - 25, 2003, Cocoyoc, Mexico.
  XV Coloquio Latinoamericano de Algebra
  Bautista and the development of modern representation theory of artin algebras
  And: The shape of the module category of an artin algebra.
• Japan: October 5-13
  Foundation of the representation theory of finite dimensional algebras.
• Kolloquium Darmstadt (60. Geburtstag Christian Herrmann)