15 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- University of ÉvoraPT26 papers
- Northeastern UniversityUS4 papers
- Endicott CollegeUS2 papers
- Instituto Superior TécnicoPT2 papers
- University of TrentoIT2 papers
- AROMATH: Algebre geometrie Modelisation et AlgorithmesFR1 paper
- Boston UniversityUS1 paper
- Centre Inria d'Université Côte d'AzurFR1 paper
- Centre National de la Recherche ScientifiqueFR1 paper
- Centro de Análise Matemática Geometria e Sistemas DinâmicosPT1 paper
- Institut de Mathématiques de BourgogneFR1 paper
- Jagiellonian UniversityPL1 paper
28 papers
Artinian Gorenstein algebras of embedding dimension four and socle degree three
Pedro Macias Marques, Oana Veliche, Jerzy Weyman
We prove that in the polynomial ring , with an algebraically closed field of characteristic zero, all Gorenstein homogeneous ideals such tha…
Vector fields with big and small volume on the 2-sphere
Rui Albuquerque
We consider the problem of minimal volume vector fields on a given Riemann surface, specialising on the case of , that is, the arbitrary radius 2-sphere with two antipodal…
The volume of a unit vector field in 2 dimensions via calibrations
Rui Albuquerque
We use the theory of calibrations to write the equation of a minimal volume vector field on a given Riemann surface.
New Hsiung-Minkowski identities
R. Albuquerque
We find the first three most general Minkowski or Hsiung-Minkowski identities relating the total mean curvatures , of degrees , of a closed hypersurface immersed…
Existence of non-trivial embeddings of Interval Exchange Transformations into Piecewise Isometries
Pedro Peres, Ana Rodrigues
We prove that almost every interval exchange transformation, with an associated translation surface of genus , can be non-trivially and isometrically embedded in a family…
Minkowski identities for hypersurfaces in constant sectional curvature manifolds
R. Albuquerque
We give a new proof of the generalized Minkowski identities relating the higher degree mean curvatures of orientable closed hypersurfaces immersed in a given constant sectional cur…
Symmetric Decomposition of the Associated Graded Algebra of an Artinian Gorenstein Algebra
Anthony Iarrobino, Pedro Macias Marques
We study the symmetric subquotient decomposition of the associated graded algebras of a non-homogeneous commutative Artinian Gorenstein (AG) algebra . This decomposition a…
Skew-Symmetric Tensor Decomposition
Enrique Arrondo, Alessandra Bernardi, Pedro Macias Marques +1
We introduce the ``skew apolarity lemma'' and we use it to give algorithms for the skew-symmetric rank and the decompositions of tensors in { with $d\leq…
Notes on the Sasaki metric
Rui Albuquerque
We survey on the geometry of the tangent bundle of a Riemannian manifold, endowed with the classical metric established by S. Sasaki 60 years ago. Following the results of Sasaki,…
Free extensions and Lefschetz properties, with an application to rings of relative coinvariants
Chris McDaniel, Shujian Chen, Anthony Iarrobino +1
Graded Artinian algebras can be regarded as algebraic analogues of cohomology rings (in even degrees) of compact topological manifolds. In this analogy, a free extension of a base…
Artinian algebras and Jordan type
Anthony Iarrobino, Pedro Macias Marques, Chris McDaniel
The Jordan type of an element of the maximal ideal of an Artinian k-algebra A acting on an A-module M of k-dimension n, is the partition of n given by the Jordan block decom…
Nontrivial solutions of systems of Hammerstein integral equations with first derivative dependence
Gennaro Infante, Feliz Minhós
By means of classical fixed point index, we prove new results on the existence, non-existence, localization and multiplicity of nontrivial solutions for systems of Hammerstein inte…
The ciconia metric on the tangent bundle of an almost-Hermitian manifold
Rui Albuquerque
We find a new class of invariant metrics existing on the tangent bundle of any given almost-Hermitian manifold. We focus here on the case of Riemannian surfaces, which yield new ex…
Natural SU(2)-structures on tangent sphere bundles
R. Albuquerque
We define and study natural -structures, in the sense of Conti-Salamon, on the total space of the tangent sphere bundle of any given oriented Riemannian 3-…
Integral representation results in BVxL^p
G. Carita, E. Zappale
Integral representation results are obtained for the relaxation of some classes of energy functionals depending on two vector fields with different behaviors, which may appear in t…
A fundamental differential system of 3-dimensional Riemannian geometry
Rui Albuquerque
We briefly recall a fundamental exterior differential system introduced by the author and then apply it to the case of three dimensions. Here we find new global tensors and intrins…
On vector bundle manifolds with spherically symmetric metrics
Rui Albuquerque
We give a general description of the construction of weighted spherically symmetric metrics on vector bundle manifolds, i.e. the total space of a vector bundle , ov…
Self-duality and associated parallel or cocalibrated structures
Rui Albuquerque
We find a remarkable family of structures defined on certain principal -bundles associated with any given oriented Riemannia…
On polynomials with given Hilbert function and applications
Alessandra Bernardi, Joachim Jelisiejew, Pedro Macias Marques +1
Using Macaulay's correspondence we study the family of Artinian Gorenstein local algebras with fixed symmetric Hilbert function decomposition. As an application we give a new lower…
On invariants of almost symplectic connections
Rui Albuquerque, Roger Picken
We study the irreducible decomposition under Sp(2n, R) of the space of torsion tensors of almost symplectic connections. Then a description of all symplectic quadratic invariants o…
On the characteristic connection of gwistor space
Rui Albuquerque
We give a brief presentation of gwistor space, which is a new concept from G_2 geometry. Then we compute the characteristic torsion T^c of the gwistor space of an oriented Riemanni…
Weighted metrics on tangent sphere bundles
Rui Albuquerque
Natural metric structures on the tangent bundle and tangent sphere bundles of a Riemannian manifold with radius function enclose many important unsolved problems. Ad…
Homotheties and topology of tangent sphere bundles
Rui Albuquerque
We prove a Theorem on homotheties between two given tangent sphere bundles of a Riemannian manifold of , assuming different variable radius functions a…
On the G_2 bundle of a Riemannian 4-manifold
Rui Albuquerque
We study the natural G_2 structure on the unit tangent sphere bundle SM of any given orientable Riemannian 4-manifold M, as it was discovered in \cite{AlbSal}. A name is proposed f…