306 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- Universidade do PortoPT174 papers
- University of CoimbraPT98 papers
- University of MinhoPT81 papers
- University of LisbonPT24 papers
- Centre National de la Recherche ScientifiqueFR22 papers
- Instituto Superior TécnicoPT22 papers
- UCLouvainBE13 papers
- Universidade Federal da BahiaBR13 papers
- Centro de Análise Matemática Geometria e Sistemas DinâmicosPT10 papers
- Pontifícia Universidade Católica do Rio de JaneiroBR10 papers
- Universidad de La LagunaES9 papers
- Universidade Federal do Rio de JaneiroBR9 papers
24 papers · 1 filter
Split Courant algebroids as -structures
Paulo Antunes, Joana M. Nunes da Costa
We show that split Courant algebroids, i.e., those defined on a Whitney sum , are in a one-to-one correspondence with multiplicative curved -algebras. This…
Generic homeomorphisms have full metric mean dimension
Maria Carvalho, Fagner B. Rodrigues, Paulo Varandas
We prove that the upper metric mean dimension of -generic homeomorphisms, acting on a compact smooth boundaryless manifold with dimension greater than one, coincides with the…
Transience of conditioned walks on the plane: encounters and speed of escape
Serguei Popov, Leonardo T. Rolla, Daniel Ungaretti
We consider the two-dimensional simple random walk conditioned on never hitting the origin, which is,formally speaking, the Doob's -transform of the simple random walk with resp…
Weak equivalence of higher-dimensional automata
Thomas Kahl
This paper introduces a notion of equivalence for higher-dimensional automata, called weak equivalence. Weak equivalence focuses mainly on a traditional trace language and a new ho…
Global dynamics of Yang-Mills field and perfect-fluid Robertson-Walker cosmologies
Artur Alho, Vitor Bessa, Filipe C. Mena
We apply a new global dynamical systems formulation to flat Robertson-Walker cosmologies with a massless and massive Yang-Mills field and a perfect-fluid with linear equation of st…
Stone pseudovarieties
Jorge Almeida, Ondřej Klíma
Profinite algebras are the residually finite compact algebras; their underlying topological spaces are Stone spaces. We extend the theory of profinite algebras to a more general se…
An electrostatic interpretation of the zeros of sieved ultraspherical polynomials
K. Castillo, M. N. de Jesus, J. Petronilho
In a companion paper [On semiclassical orthogonal polynomials via polynomial mappings, J. Math. Anal. Appl. (2017)] we proved that the semiclassical class of orthogonal polynomials…
Locally countable pseudovarieties
Jorge Almeida, Ondrej Klíma
The purpose of this paper is to contribute to the theory of profinite semigroups by considering the special class consisting of those all of whose finitely generated closed subsemi…
Facets of congruence distributivity in Goursat categories
Marino Gran, Diana Rodelo, Idriss Tchoffo Nguefeu
We give new characterisations of regular Mal'tsev categories with distributive lattice of equivalence relations through variations of the so-called Triangular Lemma and Trapezoid L…
Singularity theorems and the inclusion of torsion in affine theories of gravity
Paulo Luz, Filipe C. Mena
We extend the scope of the Raychaudhuri-Komar singularity theorem of General Relativity to affine theories of gravity with and without torsion. We first generalize the existing foc…
Strong Cosmic Censorship in Horndeski Theory
Kyriakos Destounis, Rodrigo D. B. Fontana, Filipe C. Mena +1
The strong cosmic censorship hypothesis has recently regained a lot of attention in charged and rotating black holes immersed in de Sitter space. Although the picture seems to be c…
Towards non-Hermitian quantum statistical thermodynamics
Natália Bebiano, João da Providência, João P. da Providência
Non-Hermitian Hamiltonians possessing a discrete real spectrum motivated a remarkable research activity in quantum physics and new insights have emerged. In this paper we formulate…
Static compact objects in Einstein-Cartan theory
Paulo Luz, Sante Carloni
We generalize the Tolman-Oppenheimer-Volkoff equations for space-times endowed with a Weyssenhoff like torsion field in the Einstein-Cartan theory. The new set of structure equatio…
Degenerations of nilpotent associative commutative algebras
Ivan Kaygorodov, Samuel A. Lopes, Yury Popov
We give a complete description of degenerations of complex -dimensional nilpotent associative commutative algebras.
On the Maxwell-Stefan diffusion limit for a reactive mixture of polyatomic gases in non-isothermal setting
Benjamin Anwasia, Marzia Bisi, Francesco Salvarani +1
In this article we deduce a mathematical model of Maxwell-Stefan type for a reactive mixture of polyatomic gases with a continuous structure of internal energy. The equations of th…
Recognizing pro-R closures of regular languages
Jorge Almeida, José Carlos Costa, Marc Zeitoun
Given a regular language L, we effectively construct a unary semigroup that recognizes the topological closure of L in the free unary semigroup relative to the variety of unary sem…
Degenerations of nilpotent algebras
Amir Fernández Ouaridi, Ivan Kaygorodov, Mykola Khrypchenko +1
We give a complete description of degenerations of -dimensional nilpotent algebras, -dimensional nilpotent commutative algebras and -dimensional nilpotent anticommutative…
On the lattice of subgroups of a free group: complements and rank
Jordi Delgado, Pedro V. Silva
A -complement of a subgroup is a subgroup such that . If we also ask to have trivial inters…
FPC-BI: Fast Probabilistic Consensus within Byzantine Infrastructures
Serguei Popov, William J Buchanan
This paper presents a novel leaderless protocol (FPC-BI: Fast Probabilistic Consensus within Byzantine Infrastructures) with a low communicational complexity and which allows a set…
Asymptotic stability of robust heteroclinic networks
Olga Podvigina, Sofia B. S. D. Castro, Isabel S. Labouriau
We provide conditions guaranteeing that certain classes of robust heteroclinic networks are asymptotically stable. We study the asymptotic stability of ac-networks --- robust heter…
Nearly Sasakian manifolds revisited
Beniamino Cappelletti-Montano, Antonio De Nicola, Giulia Dileo +1
We provide a new, self-contained and more conceptual proof of the result that an almost contact metric manifold of dimension greater than 5 is Sasakian if and only if it is nearly…
Binary patterns in the Prouhet-Thue-Morse sequence
Jorge Almeida, Ondřej Klíma
We show that, with the exception of the words and , all (finite or infinite) binary patterns in the Prouhet-Thue-Morse sequence can actually be found in that seq…
Semantic Factorization and Descent
Fernando Lucatelli Nunes
Let be a -category with suitable opcomma objects and pushouts. We give a direct proof that, provided that the codensity monad of a morphism exists and is preser…
A proof of the -regularity conjecture in the plane
Damião J. Araújo, Eduardo V. Teixeira, José Miguel Urbano
We establish a new oscillation estimate for solutions of nonlinear partial differential equations of elliptic, degenerate type. This new tool yields a precise control on the growth…