Publications

  1. Normal subsemigroups of finite transformation semigroups, Semigroup Forum 107 (2023), 680-691.
  2. Matrix theory for independence algebras (with J. Araújo, W. Bentz, P.J. Cameron, and M. Kinyon), Linear Algebra and Its Applications  642 (2022), 221-250.
  3. Semigroups of partial transformations whose restrictions belong to a given semigroup, Semigroup Forum 104 (2022), 109-124.
  4. Maximal abelian subgroups of the finite symmetric group, International Journal of Group Theory  10 (2021), 103-124.
  5. Semigroups of partial transformations with kernel and image restricted by an equivalence (with J. Andre), Semigroup Forum 102 (2021), 10-27.
  6. The structure of centralizers in the finite symmetric inverse semigroup,  Communications in Algebra 37 (2020), 5181-5194.
  7. Second centralizers in the semigroup of injective transformations,  Asian-European Journal of Mathematics, 13 (2020), 11 pp.
  8. Conjugacy in inverse semigroups
    (with J. Araujo and M. Kinyon),  Journal of Algebra 533 (2019), 142-173.
  9. The semigroup of surjective transformations on an infinite set,  Algebra Colloquium 26 (2019), 9-22.
  10. Decidability and independence of conjugacy problems in finitely presented monoids (with J. Araujo, M. Kinyon, and A. Malheiro), Theoretical Computer Science 731 (2018), 88-98.
  11. Automorphism groups of circulant digraphs with applications to semigroup theory (with J. Araujo, W. Bentz, E. Dobson, and J. Morris), Combinatorica 38 (2018), 1-28.
  12. Centralizers of full injective transformations in the symmetric inverse semigroup, Semigroup Forum 96 (2018), 474-488.
  13. A new definition of conjugacy for semigroups, Journal of Algebra and Its Applications 17, 1850032 (2018) [20 pages].
  14. Four notions of conjugacy for abstract semigroups (with J. Araujo, M. Kinyon,  and A. Malheiro),  Proceedings of the Royal Society of Edinburgh, Section A: Mathematics  147 (2017) , 1169-1214.
  15. Directed graphs of inner translations of semigroups (with J. Araujo and W. Bentz), Semigroup Forum  94 (2016), 650-673.
  16. The commuting graph of the symmetric inverse semigroup (with J. Araujo and W. Bentz),  Israel Journal of Mathematics 207 (2015), 103-149.
  17. The largest subsemilattices of the endomorphism monoid of an independence algebra  (with J. Araujo and W. Bentz), Linear Algebra and Its Applications 458 (2014), 60-79.
  18. Automorphism groups of endomorphism monoids of free G-sets,
    Asian-European Journal of Mathematics 7 (2014), 120-134.
  19. Conjugation in semigroups  (with J. Araujo and A. Malheiro),  Journal of Algebra 403 (2014), 93-134.
  20. Centralizers in the infinite symmetric inverse semigroup, Bulletin of the Australian Mathematical Society 87 (2013), 462-479.
  21. Centralizers in the full transformation semigroup (with J. Araujo), Semigroup Forum 86 (2013), 1-31.
  22. Sn-normal semigroups of partial transformations (with S.V. Droms and R. Palomba), Algebra Colloquium 19 (2012), 947-970.
  23. A method for finding new sets of axioms for classes of semigroups (with J. Araujo), Archive for Mathematical Logic 51 (2012), 461-474.
  24. A Proof of Devadze’s Theorem on Generators of the Semigroup of Boolean Matrices, Semigroup Forum 83 (2011), 281-288.
  25. Regular centralizers of idempotent transformations (with J. Andre and J. Araujo), Semigroup Forum 82 (2011), 307-318.
  26. Infinite injective transformations whose centralizers have simple structure, Central European Journal of Mathematics 9 (2011), 23-35.
  27. Minimal paths in the commuting graphs of semigroups (with J. Araujo and M. Kinyon), European Journal of Combinatorics 32 (2011), 178-197.
  28. Centralizers in the semigroup of injective transformations on an infinite set, Bulletin of the Australian Mathematical Society 82 (2010), 305-321.
  29. Automorphisms of endomorphism semigroups of reflexive digraphs (with J. Araujo and E. Dobson), Mathematische Nachrichten 283 (2010), 939-964.
  30. General Theorems on Automorphisms of Semigroups and Their Applications (with J. Araujo), Journal of the Australian Mathematical Society 87 (2009), 1-17.
  31. Automorphisms of endomorphism monoids if 1-simple free algebras (with J. Araujo), Communications in Algebra 37 (2009), 83-94.
  32. The monoid of holomorphic endomorphisms of a group and its automorphisms (with J. Araujo), Semigroups, Acts and Categories with Applications to Graphs, 7-13, Mathematics Studies (Tartu) 3, Estonian Mathematical Society, Tartu, 2008.
  33. Automorphisms of endomorphism monoids of relatively free bands (with J. Araujo), Proceedings of the Edinburgh Mathematical Society 50 (2007), 1-21.
  34. A method of finding automorphism groups of endomorphism monoids of relational systems (with J. Araujo), Discrete Mathematics 307 (2007), 1609-1620.
  35. Balanced subgroups of symmetric groups (with L. Lehman and S. Lipscomb), JP Journal of Algebra, Number Theory and Applications 5 (2005), 307-329.
  36. Dense relations are determined by their endomorphism monoids (with J. Araujo), Semigroup Forum 70 (2005), 302-306.
  37. Semigroups of transformations preserving an equivalence relation and a cross-section (with J. Araujo), Communications in Algebra 32 (2004), 1917-1935.
  38. Semigroups of transformations commuting with injective nilpotents, Communications in Algebra 32 (2004), 1551-1569.
  39. Automorphism groups of centralizers of idempotents (with J. Araujo), Journal of Algebra 269 (2003), 227-239.
  40. Regular, inverse, and completely regular centralizers of permutations, Mathematica Bohemica 128 (2003), 179-186.
  41. The class equation and counting in factorizable monoids (with S. Lipscomb), Proceedings of the American Mathematical Society 131 (2003), 3345-3351.
  42. Molaei’s generalized groups are completely simple semigroups (with J. Araujo), Bulletin of the Polytechnic Institute of Jassy 48 (2002), 1-5.
  43. Semigroups of transformations commuting with idempotents, Algebra Colloquium 9 (2002), 121-134.
  44. The semigroup generated by regular Boolean matrices, Southeast Asian Bulletin  of Mathematics 25 (2002), 627-641.
  45. Second centralizers of partial transformations, Czechoslovak Mathematical Journal 51 (2001), 873-888.
  46. Green’s relations and regularity in centralizers of permutations, Glasgow Mathematical Journal 41 (1999), 45-57.
  47. Centralizers in the semigroup of partial transformations (with S. Lipscomb), Mathematica Japonica 48 (1998), 367-376.
  48. Centralizers of permutations in the partial transformation semigroup (with S. Lipscomb), Pure Mathematics and Applications 6 (1995), 349-354.
  49. Reduced idempotents in the semigroup of Boolean matrices, Journal of Symbolic Computation 20 (1995), 471-482.
  50. Classification of Sn-normal semigroups (with S. Lipscomb), Semigroup Forum 51 (1995), 73-86.
  51. Green’s equivalences in finite semigroups of binary relations, Semigroup Forum 48 (1994), 235-252.
  52. Remarks on the structure of the multiplicative monoid of integers modulo m, Semigroup Forum 46 (1993), 266-269.
  53. On cardinalities of row spaces of Boolean matrices, Semigroup Forum 44 (1992), 393-402.
  54. On interleaving behaviour of PT-nets (with K. Jojczyk and T. Kuzak), Theoretical Computer Science 64 (1989), 25-38.