Erkko Lehtonen

Talks

Conference talks

  1. On clonoids of Boolean functions (keynote speaker) [slides]
    17th International Conference of Young Algebraists in Thailand (ICYAT2024), Rajamangala University of Technology Isan, Khon Kaen, Thailand, 21–23 Mar. 2024
  2. Permutation groups and permutation patterns
    UAE Math Day 2024, New York University Abu Dhabi, United Arab Emirates, 2 Mar. 2024
  3. On clonoids of Boolean functions (invited plenary lecture) [slides]
    104th Workshop on General Algebra (AAA104), Blagoevgrad, Bulgaria, 8–11 Feb. 2024
  4. Near-unanimity-closed minions of Boolean functions [slides]
    103rd Workshop on General Algebra (AAA103), Tartu, Estonia, 9–11 June 2023
  5. Associative spectra of graph algebras (keynote speaker) [slides]
    16th International Conference of Young Algebraists in Thailand (16th ICYAT-MJU), Maejo University, Chiang Mai, Thailand, 24–25 Mar. 2023
  6. Reconstructing Young tableaux
    Encontro Nacional da Sociedade Portuguesa de Matemática (ENSPM 2022), Tomar, Portugal, 18–20 July 2022
  7. On clonoids of Boolean functions
    102nd Workshop on General Algebra (AAA102), Szeged, Hungary, 24–26 June 2022
  8. Reflections and powers of multisorted minions
    Honorary colloquium on the occasion of Reinhard Pöschel’s 75th birthday, Dresden, Germany, 9 June 2022
  9. Associative spectra of groupoids
    Finnish Mathematical Days 2022, Tampere, Finland (online), 4–5 Jan. 2022
  10. Permutation groups and permutation patterns
    Permutation Patterns 2021 Virtual Workshop (PP2021), University of Strathclyde, Glasgow, United Kingdom (online), 15–16 June 2021
  11. On clonoids of Boolean functions
    100th Workshop on General Algebra (AAA100), Kraków, Poland (online), 5–7 Feb. 2021
  12. Linearly definable classes of Boolean functions
    Algebras, Graphs and Ordered Sets (ALGOS 2020), Nancy, France (online), 26–28 Aug. 2020
  13. Associative spectra of graph algebras
    99th Workshop on General Algebra (AAA99), Siena, Italy, 21–23 Feb. 2020
  14. Associative spectra of graph algebras
    97th Workshop on General Algebra (AAA97), Vienna, Austria, 1–3 Mar. 2019
  15. Functions with a unique identification minor
    96th Workshop on General Algebra (AAA96), Darmstadt, Germany, 1–3 June 2018
  16. Minors of multisorted functions and reflections
    95th Workshop on General Algebra (AAA95), Bratislava, Slovakia, 9–11 Feb. 2018
  17. Reflection-closed varieties of multisorted algebras and minor identities II
    94th Workshop on General Algebra (AAA94) and 5th Novi Sad Algebraic Conference (NSAC 2017), Novi Sad, Serbia, 15–18 June 2017
  18. Patterns and minors of permutations
    93rd Workshop on General Algebra (AAA93), Bern, Switzerland, 10–12 Feb. 2017
  19. Permutation classes closed under pattern involvement and composition
    54th Summer School on General Algebra and Ordered Sets (SSAOS 2016), Trojanovice, Czech Republic, 3–9 Sept. 2016
  20. Permutation classes closed under pattern involvement and composition
    92nd Workshop on General Algebra (AAA92), Prague, Czech Republic, 27–29 May 2016
  21. Reconstructing functions and unique identification minors
    91st Workshop on General Algebra (AAA91), Brno, Czech Republic, 5–7 Feb. 2016
  22. Reconstructing functions from identification minors
    Finnish Mathematical Days 2016, Turku, Finland, 7–8 Jan. 2016
  23. Order of first occurrence and minors of functions
    Colloquium on Combinatorics (KolKom 2015), Ilmenau, Germany, 6–7 Nov. 2015
  24. Finite characterizability of equational classes of threshold functions
    Algebra Workshop 2014 — 34 years of CAUL, Lisbon, Portugal, 19–21 Nov. 2014
  25. Reconstructing functions from identification minors
    Workshop on Computational Algebra 2014, Lisbon, Portugal, 21–23 July 2014
  26. Finite characterizability of equational classes of threshold functions
    Algebras & Clones fest, Prague, Czech Republic, 30 June – 3 July 2014
  27. Associativity, preassociativity, and string functions
    88th Workshop on General Algebra (AAA88), Warsaw, Poland, 19–22 June 2014
  28. Reconstructing functions from identification minors
    4th Novi Sad Algebraic Conference (NSAC 2013), Novi Sad, Serbia, 5–9 June 2013
  29. Reconstructing functions from identification minors
    86th Workshop on General Algebra (AAA86), Olomouc, Czech Republic, 30 May – 2 June 2013
  30. Reconstructing functions of several arguments from identification minors
    Colloquium on Combinatorics (KolKom 2012), Berlin, Germany, 16–17 Nov. 2012
  31. Generalized entropy in algebras with neutral element and in inverse semigroups
    84th Workshop on General Algebra (AAA84), Dresden, Germany, 8–10 June 2012
  32. The arity gap, or on the effect of identification of arguments on the essential arity of functions
    1st Joint Conference of the Belgian, Royal Spanish and Luxembourg Mathematical Societies (BSL-2012), Liège, Belgium, 6–8 June 2012
  33. Gap vs. pag
    IEEE 42nd International Symposium on Multiple-Valued Logic (ISMVL 2012), Victoria, BC, Canada, 14–16 May 2012
  34. Generalized entropy in algebras with neutral element and in inverse semigroups
    83rd Workshop on General Algebra (AAA83), Novi Sad, Serbia, 15–18 Mar. 2012
  35. The arity gap, or on the effect of variable identification on the essential arity of functions
    Finnish Mathematical Days 2012, Lappeenranta, Finland, 4–5 Jan. 2012
  36. Partial orders and equivalences induced by clones, especially by Post’s classes
    Second International Conference on Order, Algebra, and Logics (OAL2.0), Kraków, Poland, 6–10 June 2011
  37. A survey on the arity gap
    IEEE 41st International Symposium on Multiple-Valued Logic (ISMVL 2011), Tuusula, Finland, 23–25 May 2011
  38. Partial orders induced by the clones of Boolean clique functions and hypergraph homomorphisms
    Colloquium on Graph Theory & Applications, Luxembourg, Luxembourg, 25 Mar. 2011
  39. Embeddability of countable posets with finite principal ideals into partial orders induced by clones
    81st Workshop on General Algebra (AAA81), Salzburg, Austria, 3–6 Feb. 2011
  40. Commuting polynomial functions over distributive lattices
    Summer School on General Algebra and Ordered Sets (SSAOS 2010), Malenovice, Czech Republic, 4–10 Sept. 2010
  41. Commuting polynomial functions over distributive lattices
    13th International Conference on Information Processing and Management of Uncertainty in Knowledge-Based Systems (IPMU 2010), Dortmund, Germany, 28 June – 2 July 2010
  42. Commuting polynomial functions over distributive lattices
    International Conference on Algebras and Lattices (Jardafest), Prague, Czech Republic, 21–25 June 2010
  43. Self-commuting lattice polynomial functions
    BLAST 2010, Boulder, CO, USA, 2–6 June 2010
  44. Classes of operations closed under permutation, cylindrification and composition
    40th International Symposium on Multiple-Valued Logic (ISMVL 2010), Barcelona, Spain, 26–28 May 2010
  45. Galois theories for function algebras
    Finnish Mathematical Days 2010, Jyväskylä, Finland, 4–5 Jan. 2010
  46. Clones of Boolean clique functions and hypergraph homomorphisms
    3rd Novi Sad Algebraic Conference (NSAC 2009), Novi Sad, Serbia, 17–21 Aug. 2009
  47. Reducts of Malʹcev’s iterative algebra and preservation of generalized relations
    78th Conference on General Algebra (AAA78), Bern, Switzerland, 11–14 June 2009
  48. On the finite index property of clones
    77th Workshop on General Algebra (AAA77) & 24th Conference for Young Algebraists, Potsdam, Germany, 20–22 Mar. 2009
  49. The arity gap and generalizations of Świerczkowski’s lemma
    Summer School on General Algebra and Ordered Sets (SSAOS 2008), Třešť, Czech Republic, 31 Aug. – 6 Sept. 2008
  50. The arity gap of finite functions and generalizations of Świerczkowski’s lemma
    BLAST, Denver, CO, USA, 6–10 Aug. 2008
  51. On the arity gap of finite functions: results and applications
    International Conference on Relations, Orders and Graphs: Interaction with Computer Science (ROGICS ’08), Mahdia, Tunisia, 12–17 May 2008
  52. Operations on finite sets, functional composition, and ordered sets
    Finnish Mathematical Days 2008, Espoo, Finland, 3–4 Jan. 2008
  53. Equivalence of operations with respect to discriminator clones
    74th Workshop on General Algebra (AAA74), Tampere, Finland, 7–10 June 2007
  54. On homomorphisms of labeled posets
    73rd Workshop on General Algebra (AAA73) & 22nd Conference of Young Algebraists (CYA22), Klagenfurt, Austria, 1–4 Feb. 2007
  55. Subfunctions and Burle’s clones
    Workshop Algebra and its applications, Kokõ, Estonia, 5–7 May 2006
  56. Subfunction relations defined by the clones of monotone functions on a finite set
    Finnish Mathematical Days 2006 & 2nd Finnish-Estonian Mathematical Colloquium, Tampere, Finland, 4–5 Jan. 2006
  57. Compositions of Boolean functions with monotone functions
    Novi Sad Algebraic Conference (NSAC ’05), Novi Sad, Serbia and Montenegro, 11–15 July 2005
  58. Hypergraph homomorphisms and compositions of Boolean functions with clique functions
    Conference on Universal Algebra and Lattice Theory, Szeged, Hungary, 4–8 July 2005
  59. On subfunctions of Boolean functions
    70th Workshop on General Algebra (AAA70), Vienna, Austria, 26–29 May 2005
  60. On compositions of clones of Boolean functions
    International Conference of Computational Methods in Sciences and Engineering 2004 (ICCMSE 2004), Vouliagmeni, Attica, Greece, 19–23 Nov. 2004

Seminar talks

  1. The associative spectrum of a binary operation [slides]
    Department of Mathematical Sciences, United Arab Emirates University, Al Ain, United Arab Emirates, 17 Nov. 2023
  2. On clonoids of Boolean functions [slides]
    Panglobal Algebra and Logic Seminar (PALS), Department of Mathematics, University of Colorado at Boulder, USA (online), 17 Oct. 2023
  3. Associative spectra of graph algebras
    Department of Mathematics and Statistics, American University of Sharjah, United Arab Emirates, 23 Nov. 2022
  4. Associative spectra of graph algebras
    Seminar on Semigroups, Automata and Languages, Centre of Mathematics, University of Porto, Portugal (online), 11 Nov. 2022
  5. Associative spectra of graph algebras
    Mathematics and Applications Colloquium, Mathematics Department, Khalifa University, Abu Dhabi, United Arab Emirates, 15 Sept. 2022
  6. On clonoids of Boolean functions
    Institute for Algebra, Johannes Kepler University Linz, Austria, 31 Mar. 2022
  7. On clonoids of Boolean functions
    Faculty of Information Technology and Communication Sciences, Tampere University, Finland (online), 14 Jan. 2022
  8. On clonoids of Boolean functions
    MALOTEC Seminar, Loria (Laboratoire lorrain de recherche en informatique et ses applications), Vandœuvre-lès-Nancy, France (online), 16 Dec. 2021
  9. On clonoids of Boolean functions
    Faculty of Science and Technology, Universidade Nova de Lisboa, Portugal (online), 29 Nov. 2021
  10. On clonoids of Boolean functions
    Computer and Systems Laboratory (LIS), Aix-Marseille University, Marseille, France (online), 22 Nov. 2021
  11. On clonoids of Boolean functions [slides]
    Department of Mathematics, University of Lisbon, Portugal (online), 16 Nov. 2021
  12. Permutation groups and permutation patterns [slides]
    Institute of Mathematics and Informatics, Bulgarian Academy of Science, Sofia, Bulgaria (online), 5 Nov. 2021
  13. Associative spectra of graph algebras
    MALOTEC Seminar, Loria (Laboratoire lorrain de recherche en informatique et ses applications), Vandœuvre-lès-Nancy, France (online), 6 May 2021
  14. Associative spectra of graph algebras
    New York Combinatorics Seminar, The Graduate Center, City University of New York, USA (online), 12 Mar. 2021
  15. Associative spectra of graph algebras
    Panglobal Algebra and Logic Seminar (PALS), Department of Mathematics, University of Colorado at Boulder, USA (online), 17 Nov. 2020
  16. Associative spectra of graph algebras
    Faculty of Science and Technology, Universidade Nova de Lisboa, Portugal, 9 Mar. 2020
  17. Permutation groups and permutation patterns
    Faculty of Science and Technology, Universidade Nova de Lisboa, Portugal, 4 Nov. 2019
  18. Permutation groups and permutation patterns
    Faculty of Information Technology and Communication Sciences, Tampere University, Finland, 27 Sept. 2019
  19. Permutation groups and permutation patterns
    Department of Mathematics and Statistics, University of Turku, Finland, 26 Sept. 2019
  20. Permutation groups and permutation patterns
    Mathematics Research Unit, University of Luxembourg, Luxembourg, 26 Aug. 2019
  21. Associative spectra of graph algebras
    Institute of Mathematics, University of Debrecen, Hungary, 25 Apr. 2019
  22. Graph algebras and graph varieties
    Institute of Algebra, Dresden University of Technology, Germany, 19 Oct. 2018
  23. Graph algebras and graph varieties
    Bolyai Institute, University of Szeged, Hungary, 26 Sept. 2018
  24. Reflection-closed varieties of multisorted algebras and minor identities
    Institute of Mathematics, University of Potsdam, Germany, 28 May 2018
  25. Reflection-closed varieties of multisorted algebras and minor identities
    Institute of Algebra, Dresden University of Technology, Germany, 9 June 2017
  26. Permutation patterns, permutation groups, and invariance groups of functions
    Institute of Mathematics, University of Wrocław, Poland, 7 June 2017
  27. Reconstructibility of functions and minors of permutations
    Bolyai Institute, University of Szeged, Hungary, 8 Mar. 2017
  28. Majors of functions
    Institute of Algebra, Dresden University of Technology, Germany, 27 Jan. 2017
  29. Minors of functions and permutations, reconstruction problems, and the order of first occurrence
    Institute of Algebra, Dresden University of Technology, Germany, 14 Oct. 2016
  30. Permutation groups, pattern involvement, and Galois connections
    Institute of Mathematics, University of Potsdam, Germany, 12 May 2016
  31. Permutation groups, pattern involvement, and Galois connections
    Institute of Discrete Mathematics and Algebra, Technische Universität Bergakademie Freiberg, Germany, 10 May 2016
  32. Permutation groups, pattern involvement, and Galois connections
    Institute of Algebra, Dresden University of Technology, Germany, 15 Apr. 2016
  33. On permutation groups and permutation pattern classes
    Bolyai Institute, University of Szeged, Hungary, 10 Feb. 2016
  34. On permutation groups and permutation pattern classes
    Institute of Algebra, Dresden University of Technology, Germany, 18 Dec. 2015
  35. On the reconstructibility of functions from identification minors
    Institute of Algebra, Dresden University of Technology, Germany, 22 May 2015
  36. Homomorphisms of labeled posets
    Loria (Laboratoire lorrain de recherche en informatique et ses applications), Vandœuvre-lès-Nancy, France, 5 May 2015
  37. Reconstructing functions from identification minors
    School of Information Sciences, University of Tampere, Finland, 9 Jan. 2015
  38. Reconstructing functions from identification minors
    Centre of Mathematics, University of Porto, Portugal, 12 June 2014
  39. Reconstructing functions of several arguments from identification minors
    Institute for Interdisciplinary Research, University of Lisbon, Portugal, 16 Dec. 2013
  40. Recent advances in the reconstruction problem for functions and identification minors
    Mathematics Research Unit, University of Luxembourg, Luxembourg, 17 Apr. 2013
  41. Commuting polynomial operations of distributive lattices
    Mathematics Research Unit, University of Luxembourg, Luxembourg, 22 Nov. 2012
  42. Reconstructing functions of several arguments from identification minors
    Mathematics Research Unit, University of Luxembourg, Luxembourg, 18 Oct. 2012
  43. Reconstruction problem for functions and identification minors
    Faculty of Mathematics and Information Sciences, Warsaw University of Technology, Poland, 12 June 2012
  44. Generalized entropy in inverse semigroups and in algebras with neutral element
    Bolyai Institute, University of Szeged, Hungary, 29 Feb. 2012
  45. Commuting polynomial operations of distributive lattices
    Mathematics and Statistics, School of Information Sciences, University of Tampere, Finland, 9 Sept. 2011
  46. Commuting polynomial operations of distributive lattices
    Department of Algebra, Johannes Kepler University Linz, Austria, 16 Aug. 2011
  47. Commuting polynomial operations of distributive lattices
    Institute of Mathematics, University of Miskolc, Hungary, 12 Aug. 2011
  48. Commuting polynomial operations of distributive lattices
    Department of Mathematics and Informatics, University of Novi Sad, Serbia, 27 June 2011
  49. Commuting polynomial operations of distributive lattices
    Institute of Mathematics, University of Rostock, Germany, 20 Apr. 2011
  50. Commuting polynomial operations of distributive lattices
    Faculty of Mathematics and Information Sciences, Warsaw University of Technology, Poland, 1 Mar. 2011
  51. Partial orders and equivalences induced by clones
    Bolyai Institute, University of Szeged, Hungary, 1 Dec. 2010
  52. Partial orders and equivalences induced by clones
    Institute of Algebra, Dresden University of Technology, Germany, 14 Sept. 2010
  53. How does identification of arguments affect the number of essential arguments of functions?
    Computer Science and Communication Research Unit, University of Luxembourg, Luxembourg, 17 June 2010
  54. How does identification of variables affect the number of essential variables of functions?
    Department of Algebra, Johannes Kepler University Linz, Austria, 19 May 2010
  55. Reducts of Malʹcev’s iterative algebra and generalizations of relations
    Department of Mathematics, University of Luxembourg, Luxembourg, 12 May 2009
  56. Reducts of Malʹcev’s iterative algebras and generalizations of relations
    Department of Mathematics, State University of New York at New Paltz, USA, 8 Dec. 2008
  57. A brief introduction to clone theory
    Department of Mathematics and Engineering, Harold Washington College, Chicago, IL, USA, 4 Dec. 2008
  58. Reducts of Malʹcev’s iterative algebra and generalizations of relations
    Department of Mathematics & Statistics, McMaster University, Hamilton, Canada, 21 Oct. 2008
  59. C-minors of operations and the arity gap
    Department of Mathematics, Brock University, St. Catharines, Canada, 24 Oct. 2007
  60. Subfunction relations defined by function classes
    Department of Combinatorics and Optimization, University of Waterloo, Canada, 12 July 2006
  61. Composition of Post classes and normal forms of Boolean functions
    RUTCOR — Rutgers Center for Operations Research, Piscataway, NJ, USA, 1 June 2006
  62. Compositions of k-valued logic functions with monotone functions
    Institute of Mathematics, Tampere University of Technology, Finland, 16 Mar. 2006
  63. Subfunction relations defined by function classes
    Department of Mathematics, University of Helsinki, Finland, 21 Oct. 2005
  64. Subfunction relations defined by function classes
    Institute of Mathematics, Tampere University of Technology, Finland, 15 Sept. 2005
  65. C-subfunctions of Boolean functions
    Institute of Mathematics, University of Miskolc, Hungary, 23 May 2005
  66. Composition algebra of Boolean functions, functions of several variables, and function classes
    Institute of Mathematics, Tampere University of Technology, Finland, 2 Dec. 2004