Research Interests

Algebraic and Enumerative Combinatorics, Ordered Algebraic Structures

Research Unit

Centre for Mathematics of the University of Coimbra - (research group:  Algebra and Combinatorics)

Publications

A characterization of one-element commutation classes  (with J.L. Santos and D. Soares). The Electronic Journal of Combinatorics, 31(4)  (2024), P4.69.

Diameter of a commutation class on reduced words (with G. Gutierres). Discrete Mathematics 347 (2024), paper no. 114098.

O Teorema de Gauss-Lucas, Canto Délfico, Gazeta de Matemática da SPM n.◦ 199 (2023).

O Teorema dos Rearranjos de Riemann, Canto Délfico, Gazeta de Matemática da SPM n. 198 (2022).

A função W de Lambert, Canto Délfico, Gazeta de Matemática da SPM n. 197 (2022).

The commutation graph for the longest signed permutation (with J.L. Santos and D. Soares). Discrete Mathematics, volume 345, Issue 11 (2022), paper no. 113055.

Diameter of the commutation classes graph of a permutation (with G. Gutierres and J.L. Santos). European Journal of Combinatorics, 103 (2022),  paper no.103525.

Commutation classes of the reduced words for the longest element of Sn  (with G. Gutierres and J.L. Santos).  The Electronic Journal of Combinatorics, volume 27, Issue 2 (2020), P2.21.

Multiplicity-free skew Schur functions with full interval support (with O. Azenhas and A. Conflitti). Séminaire Lotharingien de Combinatoire, vol 75 (2019) Article B75j,  34pp.

Optimal Gray code for involutions (with G. Gutierres and J.L. Santos). Information Processing Letters, Vol. 148 (2019), pp. 19-22.

Gray codes for signed involutions (with G. Gutierres and J. L. Santos), Discrete Mathematics, Vol. 341 (2018), N.9, pp. 2590-2601.

Gray codes for noncrossing and nonnesting partitions of classical types (with A. Conflitti), International Journal of Algebra and Computation, Vol. 27 (2017), No. 05, pp. 455-475.

Chains and Antichains in the Bruhat Order for Classes of (0, 1)-Matrices, Applied and Computational Matrix Analysis, Springer Proceedings in Mathematics & Statistics (2017), pp. 219-239.

Gray codes and lexicographical combinatorial generation for nonnesting and sparse nonnesting set partitions (with A. Conflitti), Theoret. Comput. Sci., Volume 592 (2015), pp. 87–96.

Singleton free set partitions avoiding a 3-element set, Dynamic, Games, and Science III, Springer Verlag, CIM series in Mathematical Sciences (2015), pp. 379-397.

Dominant Shi regions with a fixed separating wall: bijective enumeration (with A. Conflitti and E. Tzanaki), The Australasian Journal of Combinatorics, Vol. 60 (2014), pp. 198-207.

On the largest size of an antichain in the Bruhat order for A(2k,k) (with A. Conflitti and C. M. da Fonseca), Order, Vol. 30 (2013), Issue 1, pp. 255-260.

The maximal length of a chain in the Bruhat order for a class of binary matrices (with A. Conflitti and C. M. da Fonseca), Linear Algebra and its Applications, Vol. 436 (2012), Issue 3, pp. 753-757.

On Noncrossing and nonnesting partitions of type D (with A. Conflitti), Annals of Combinatorics, 15 (2011), pp. 637-654.

A bijection between noncrossing and nonesting partitions of types A, B and C, Contributions to Discrete Mathematics , Vol. 6 (2011), No 2, pp. 70-90.

On the number of P-vertices of some graphs, (with M. Andelic and C.M. da Fonseca), Linear Algebra and its Applications, Vol. 434 (2011), Issue 2, pp. 514-525.

Números (coeficientes) de Littlewood-Richardson e simetrias, (with O. Azenhas and A. Conflitti), Boletim da Sociedade Portuguesa de Matemática, Actas do Encontro Nacional da SPM 2010, pp. 5-14.

Bijecções entre partições que não cruzam e partições que não encaixam, (with A. Conflitti), Boletim da Sociedade Portuguesa de Matemática, Actas do Encontro Nacional da SPM 2010, pp. 20-27.

Matrix Tableau-Pairs with Key and Shuffling Conditions (with O. Azenhas), Séminaire Lotharingien de Combinatoire, 57 (2010), Article B57f, 38pp.

Actions of the Symmetric Group Generated by Comparable Sets of Integers and Smith Invariants (with O. Azenhas),Séminaire Lotharingien de Combinatoire, 59 (2010), Article B59g, 27pp.

Linear time equivalence of Littlewood-Richardson coefficient symmetry maps (with O. Azenhas and A. Conflitti), Discrete Mathematics & Theoretical Computer Science Proc. AK, 2009, 127-144.

A bijection between noncrossing and nonesting partitions of types A and B, Discrete Mathematics & Theoretical Computer Science Proc. AK, 2009, 597-610.

Dos quadros de Young às matrizes de zeros e uns (with C.M. da Fonseca), Boletim da Sociedade Portuguesa de Matemática, n.º60, Maio 2009, 23-33.

On (0,1)-matrices with prescribed row and column sum vectors (with C.M. da Fonseca), Discrete Math. 309 (2009), 2519-2527.

Matrix realizations of pairs of Young tableaux, keys and shuffles (with O. Azenhas), Séminaire Lotharingien de Combinatoire, 53 (2006), article B53h, 22pp.

Realizações matriciais de pares de tableaux de Young e palavras francas (with O. Azenhas), Actas do Encontro de Algebristas Portugueses/2005, Universidade do Minho, (2006), pp. 19-37.

Action of the symmetric group on sets of skew-tableaux with prescribed matrix realization (with O. Azenhas),Linear Algebra and its Applications 401 (2005), pp. 221-275.

Other publications

Chaves, Palavras Francas e Realizações Matriciais de Pares de Quadros de Young, Phd Thesis, Universidade de Coimbra, 2006.

Permutações de Sequências de Littlewood-Richardson e Suas Realizações Matriciais, Master Thesis, Universidade de Coimbra, 2001.