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João Araújo

Institutional Address

Universidade Nova de Lisboa
Departamento de Matemática,
Faculdade de Ciências e Tecnologia,
Quinta da Torre
2829-516 CAPARICA

Phone: | Email: jjrsga@gmail.com

Position

Full Professor

Area

Algebra and Computing

Principal Area

Semigroups, groups, combinatorics and and computational algebra

Qualifications

Habilitation in Mathematics, University of Lisbon, 2011.
PhD in mathematics, University of York, UK, 2000, KM Stott Memorial Prize.
MSc in Mathematics, University of Lisbon, 1994.
Degree in mathematics, University of Lisbon, 1991.

Papers in International Journals

Araújo, João; Kinyon, M.; Vigário, Edgar (2019) Short equational bases for MV-Algebras, commutative BCK-Algebras and LBCK-algebras . (submitted).

Araújo, João; Cameron, P. J. (2019) Primitive groups, road closures, and idempotent generation . (submitted).

Araújo, João; Kinyon, M.; R. Padmanabhan (2019) A 2-base for inverse semigroups . (submitted).

Araújo, João; Kinyon, M. (2018) Decidability and Independence of Conjugacy Problems in Finitely Presented Monoids . Theoretical Computer Science.

Araújo, João; Gomes, Gracinda M. S.; Bentz, Wolfram (2018) Congruences on direct products of transformation and matrix monoids . Semigroup Forum: 97, 384-416.

Araújo, João; Bentz, Wolfram; Cameron, P. J. (2018) Orbits of Primitive k-Homogenous Groups on (n-k)-Partitions with Applications to Semigroups . Transactions of the American Mathematical Society.

Araújo, João; Cameron, P. J.; Hulpke, A.; Lopes,P. (2017) Imprimitive Permutations in Primitive Groups . Journal of Algebra: 486, 396-416.

Araújo, João; Kinyon, M.; Konieczny, J.; Martins, Nuno F. M. (2017) Four notions of conjugacy for abstract semigroups . Proceedings of the Royal Society of Edinburgh Section A: Mathematics: volume 147, issue 6, 1169-1214.

Araújo, João; Janusz Konieczny; António Malheiro (2017) Four Notions of Conjugacy for Abstract Semigroups . Proceedings of the Royal Academy of the Edinbourgh Mathematical Society: 147 A, 1169-1214.

Araújo, João; Peter J Cameron; Benjamin Steinberg (2017) Between primitive and $2$-transitive: Synchronization and its friends . European Mathematical Society Surveys: 4:2, 101-184.

Araújo, João; Bentz, Wolfram; Janusz Konieczny; Joy Morris (2017) Automorphism Groups of Circulant Digraphs with Applications to Semigroup Theory . Combinatorica, 1-28.

Araújo, João; Bentz, Wolfram; Janusz Konieczny (2017) Directed graphs of inner translations of semigroups . Semigroup Forum: 94(3), 650-673.

Araújo, João; Cameron, Peter (2016) Two Generalizations of Homogeneity in Groups with Applications to Regular Semigroups . Trans. Amer. Math. Soc.: 368, 1159--1188.

André, Jorge M.; Araújo, João; Cameron, Peter (2016) The classification of partition homogeneous groups with applications to semigroup theory . Journal of Algebra: 452, 288--310.

Araújo, João; Bentz, Wolfram; Cameron, P. J.; Gordon Royle; Artur Schaefer (2016) Primitive Groups, Graph Endomorphisms and Synchronization . Proceedings of the London Mathematical Society: 113, 829--867.

Araújo, João; Bentz, Wolfram; Mitchell, James D.; Schneider, Csaba (2015) The rank of the semigroup of transformations stabilising a partition of a finite set . Math. Proc. Cambridge Philos. Soc.: 159, 339-353.

Araújo, João; Kinyon, M. (2015) A natural characterization of semilattices of rectangular bands and groups of exponent two . Semigroup Forum: 91, 295-298.

Araújo, João; Cameron, Peter (2014) Primitive Groups Synchronize Non-uniform Maps of Extreme Ranks . Journal of Combinatorial Theorie, Series B: 106, 98-114.

Araújo, João; Kinyon, M. (2014) Inverse semigroups with idempotent-fixing automorphisms . Semigroup Forum: 89(2), 469-474.

Araújo, João; Bentz, Wolfram; Janusz Konieczny (2014) The Commuting Graph of the Symmetric Inverse Semigroup . Israel Journal of Mathematics: 207, 103-149.

Araújo, João; Janusz Konieczny; Malheiro, António (2014) Conjugation in semigroups . Journal of Algebra: 403, 93-134.

Araújo, João; Bentz, Wolfram; Konieczny, Janusz (2014) The largest subsemilattices of the endomorphism monoid of an independence algebra . Linear Algebra and its Applications: 458, 50-79.

Araújo, João; Bentz, Wolfram; Cameron, Peter (2013) Groups synchronizing a transformation of non-uniform kernel . Theoretical Computer Science: 498, 1--9.

Araújo, João; Cameron, Peter; Mitchell, James D.; Neunhöffer, Max (2013) The classification of normalizing groups . Journal of Algebra: 373, 481-490.

Araújo, João; Kinyon, M.; Malheiro, António (2013) A characterization of adequate semigroups by forbidden subsemigroups . Proceedings of the Royal Society of Edinburgh Series A: 143(6), 1115-1122.

Araújo, João; Konieczny, Janusz (2013) Centralizers in the Full Transformation Semigroup . Semigroup forum: 86(1), 1-31.

Araújo, João; Kinyon, M. (2012) On a Problem of M. Kambites Regarding Abundant Semigroups . Communications in Algebra: 40(12), 4439–4447.

Araújo, João; Konieczny, Janusz (2012) A Method for Finding New Sets of Axioms for Classes of Semigroups . Archives for Mathematical Logic: 51(5-6), 461-474.

Araújo, João; Kinyon, M. (2012) Axioms for Unary Semigroups Via Division Operations . Communications in Algebra: 40(2), 719-737.

Araújo, João; Edmundo, M.; Givant, S. (2011) v*-algebras, Independence Algebras and Logic . International Journal on Algebra and Computation: 21, 7, 1237-1257.

Araújo, João; Kinyon, M. (2011) Independent axiom systems for nearlattices . Czechoslovak Mathematical Journal: 61(4), 975-992.

Araújo, João; Mitchell, James D.; Schneider, Csaba (2011) Groups that together with any transformation generate regular semigroups or idempotent generated semigroups . Journal of Algebra: 343(1), 93-106.

Araújo, João; Kinyon, M.; Konieczny, J. (2011) Minimal Paths in the Commuting Graphs of Semigroups . European Journal of Combinatorics: 32, 178-197.

Araújo, João; Malheiro, António (2011) On finite complete presentations and exact decompositions of semigroups . Communications in Algebra: 39, 10, 3866--3878.

Araújo, João; Kinyon, M. (2011) An Elegant 3-Basis for Inverse Semigroups . Semigroup Forum: 82(2), 319-323.

Araújo, João; Fernandes, Vítor Hugo; Jesus, Manuel M.; Maltcev, Victor; Mitchell, James D. (2011) Automorphisms of partial endomorphism semigroups . Publicationes Mathematicae Debrecen: 79(1-2), 23-29.

André, Jorge M.; Araújo, João; Konieczny, J. (2011) Regular centralizers of idempotent transformations . Semigroup Forum: 82(2), 307-318.

Araújo, João; Dobson, Edward; Konieczny, Janusz (2010) Automorphisms of Endomorphism Semigroups of Reflexive Digraphs . Mathematische Nachrichten: 283(7), 1-26.

Araújo, João; McCune, William (2010) Computer Solutions of Problems in Inverse Semigroups . Communications in Algebra: 38(3), 1104-1121.

Araújo, João; Bunau, P. V.; Mitchell, James D.; Neunhoeffer, M. (2010) Computing Automorphisms of Semigroups . Journal of Symbolic Computation: 45(3), 373-392.

Araújo, João; Konieczny, Janusz (2009) General Theorems on Automorphisms of Semigroups and Their Applications . Journal of the Australian Mathematical Society: 87(1), 1-17.

Araújo, João; Wehrung, Friedrich (2009) Embedding properties of endomorphism semigroups . Fundamenta Mathematicae: 202, 125-146.

Araújo, João; Konieczny, Janusz (2009) Automorphisms of Endomorphism Monoids of 1-Simple Free Algebras . Communications in Algebra: 37(1), 83-94.

Araújo, João; Schneider, Csaba (2009) The Rank of the Endomorphism Monoid of a Uniform Partition . Semigroup Froum: 78(3), 498-510.

Araújo, João; Konieczny, Janusz (2007) Automorphisms of Endomorphism Monoids of Relatively Free Bands . Proceedings of the Edinburgh Mathematical Society: 50, 1-21.

Araújo, João; Mitchell, James D. (2007) Relative ranks in the monoid of endomorphisms of an independence algebra . Monatshefte für Mathematik: 151, 1-10.

Araújo, João; Konieczny, Janusz (2007) A Method of Finding Automorphism Groups of Endomorphism Monoids of Relational Systems . Discrete Mathematics: 307, 1609-1620.

Araújo, João (2006) Lifts for Semigroups of Endomorphisms of an Independence Algebra . Colloquium Mathematicum: 106, 39-56.

Araújo, João; Mitchell, James D. (2005) An elementary proof that every singular matrix is a product of idempotent matrices . American Mathematical Monthly: 112 (7), 641-645.

Araújo, João; Silva, Fernando C. (2005) Semigroups of Matrices Closed Under Conjugation by Normal Linear Groups . JP Journal of Algebra and Number Theory: 5 No.3, 535-545.

Araújo, João; Fountain, John (2005) A Description of Normal Semigroups of Endomorphisms of Proper Independence Algebras . Communications in Algebra: 33, 2705-2711.

Araújo, João; Konieczny, Janusz (2005) Dense Relations Are Determined by Their Endomorphism Monoid . Semigroup Forum: 70, 2, 302-306.

Araújo, João; Konieczny, Janusz (2004) Semigroups of Transformations Preserving an Equivalence Relation and a Cross-Section . Communications in Algebra: 32, 1917-1935.

Araújo, João; Konieczny, Janusz (2003) Automorphisms Groups of Centralizers of Idempotents . Journal of Algebra: 269, 227-239.

Araújo, João (2003) Lifts for Semigroups of Monomorphisms of an Independence Algebra . Colloquium Mathematicum: 97, 277-284.

Araújo, João; Mitchell, James D.; Silva, N. (2003) On embedding countable sets of endomorphisms . Algebra Universalis: 50, 61-67.

Araújo, João (2003) Idempotent Generated Endomorphisms of an Independence Algebra . Semigroup Forum: 67, 464-467.

Araújo, João (2002) Generators for the Semigroup of Endomorphisms of an Independence Algebra . Algebra Colloquium: 9:4, 375-382.

Araújo, João (2002) Normal Semigroups of Endomorphisms of Proper Independence Algebras are Idempotent Generated . Proc. Edinburgh Math. Soc.: 45, 205-217.

Araújo, João; Konieczny, Janusz (2002) Molaei's Generalized Groups are Completely Simple Semigroups . Bul. Inst. Politeh. Jassy, Sect. I. Mat. Mec. Teor. Fiz.: 48 (52) no. 1-2, 1-5.

Araújo, João (2002) On Idempotent Generated Semigroups . Semigroup Forum: 65, 138-140.

Araújo, João; Silva, F. C. (2000) Semigroups of linear endomorphisms closed under conjugation . Comm. Algebra: 28 (8), 3679-3689.

Araújo, João; Bentz, Wolfram; Gomes, Gracinda M. S. () Congruences on Direct Products of Transformation and Matrix Monoids . Semigroup Forum: (submitted).

Papers or Chapters in Edited Books

Araújo, João; Cameron, Peter (2015) Permutation groups and transformation semigroups: results and problems . London Mathematical Society Lecture Note Series: 422, 128-141.

Araújo, João; Konieczny, Janusz (2008) The Monoid of Holomorphic Endomorphisms of a Group and its Automorphisms . Semigroups, Acts and Categories with Applications to Graphs, Estonian Mathematical Society, 7-13.

Araújo, João; Fountain, John (2004) The Origins of Independence Algebras . Proceedings of the Workshop on Semigroups and Languages (Lisbon 2002), World Scientific, 54-67.

Thesis

Araújo, João (2000) Aspects of the endomorphism monoids of independence algebras . K M Stott Memorial Prize Award Winning Ph.D. Thesis, University of York, United Kingdom.

Araújo, João (1994) Mergulhos e Coberturas de Semigrupos E-unitários, Dissertação de Mestrado em Matemática . Universidade de Lisboa.

Seminars

The Mathematician as a Manager (10/05/2013) Instituto para a Investigação Interdisciplinar da Universidade de Lisboa

Semigroups of Transformations and the classification of finite simple groups (27/02/2007) Centro de Matemática da Universidade de Coimbra

Semigroups of Transformations and the Classification of Finite Simple Groups (27/02/2007) Centro de Matemática da Universidade de Coimbra, Portugal

Tudo o que Sempre quis Saber sobre Semigrupos (e não sabia como perguntar) (08/11/2006) Universidade Aberta, Lisboa, Portugal

A John Fountain Production: João Araújo in Tales in Semigroup Theory (13/10/2006) Fountainfest "Semigroups, categories and automata", a conference celebrating John Fountain's 65th birthday and his mathematical achievements, University of York, UK

O Coelho da Cartola (02/10/2006) CELC, Lisboa, Portugal

The Gold Rush (22/06/2006) Encontro Nacional da Sociedade Portuguesa de Matemática 2006, Instituto Superior de Engenharia de Lisboa (ISEL), Portugal

Álgebras de Independência: Um Serviço de Estrangeiros e Fronteiras entre a Álgebra Linear e os Semigrupos (17/05/2004) Centre de Estruturas Lineares e Combinatórias, Universidade de Lisboa

Semigrupos que Preservam Relações de Aridade Arbitrária (13/05/2004) Universidade de Évora

Do Vitor à Victória (17/10/2003)

Independence Algebras (27/11/2002) Workshop on Semigroups and Languages, CAUL, Portugal

Semigrupos normais de endomorfismos de uma álgebra de independência (12/10/2001)

Automorfismos de Semigrupos (19/05/2000)

Conferences

Conference on Semigroups, Acts and Categories with Applications to Graphs (06/2007) University of Tartu, Estonia, 27-30/06/2007 (Contributed Talk)

Workshop Estatística, Matemática e Computação (11/2006) Universidade Aberta, Lisboa, Portugal, 8-9/11/2006 (Invited Speaker)

Fountainfest "Semigroups, categories and automata", a conference celebrating John Fountain's 65th birthday and his mathematical achievements (12/10/2006) University of York, UK, 12-14/10/2006 (Invited Speaker)

Computational and algorithmic aspects of semigroup theory - An international workshop (09/2006) St. Andrews, Scotland, 5-9/09/2006 (Invited Speaker)

Encontro Nacional da Sociedade Portuguesa de Matemática 2006 (06/2006) Instituto Superior de Engenharia de Lisboa (ISEL), Portugal, 20-23/06/2006 (Invited Speaker)

International Workshop on Semigroups and Languages (11/2002) CAUL, Lisbon, Portugal, 27-29/11/2002 (Contributed Talk)