RSS 1.0Artigos - Matemática - IBILCE
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The Cone Structure Theorem
; Costa, João Carlos Ferreira
; (International Mathematics Research Notices, 2021) [Artigo]
We consider the topological classification of finitely determined map germs f: (Rn, 0) → (Rp, 0) with f-1(0) = {0}. Associated with f we have a link diagram, which is well defined up to topological equivalence. We prove ... -
Invariant probabilities for discrete time linear dynamics via thermodynamic formalism
; Messaoudi, Ali; ; (Nonlinearity, 2021) [Artigo]
We show the existence of invariant ergodic σ-additive probability measures with full support on X for a class of linear operators L : X → X, where L is a weighted shift operator and X either is the Banach space c0(ℝ) or ... -
Chain recurrence and average shadowing in dynamics
; ; Messaoudi, Ali (Monatshefte fur Mathematik, 2021) [Artigo]
We investigate several notions related to pseudotrajectories, including chain recurrence and shadowing properties, for a special class of diffeomorphisms on euclidean spheres, known as spherical linear transformations, and ... -
Lattices from abelian extensions and error-correcting codes
; da Nóbrega Neto, Trajano Pires; ; (Rocky Mountain Journal of Mathematics, 2021) [Artigo]
A construction of laminated lattices of full diversity in odd dimensions d with 3 ≤ d ≤ 15 is presented. The technique, which uses a combination of number fields and error-correcting codes, consists essentially of two ... -
Shadowing and structural stability for operators
; Messaoudi, Ali (Ergodic Theory and Dynamical Systems, 2021) [Artigo]
A well-known result in the area of dynamical systems asserts that any invertible hyperbolic operator on any Banach space is structurally stable. This result was originally obtained by Hartman in 1960 for operators on ... -
A new number field construction of the D4-lattice
; ; da Nóbrega Neto, Trajano Pires (International Journal of Applied Mathematics, 2018) [Artigo]
A classical problem in lattice theory is to determine whether a given lattice can be realized as OK-lattice, where OK is the ring of integers of some number field K. In this work we show that the lattice D4 can be realized ... -
Four-dimensional lattices from ℚ(√2,√5)
; Neto, Trajano Pires da Nóbrega; ; (International Journal of Applied Mathematics, 2017) [Artigo]
Four-dimensional lattices with block circulant generator matrices are constructed from submodules of the ring of integers of the totally real number field ℚ(√2,√5). The obtained lattices are of full diversity and their ... -
Lattice constellations matched to GF(p)
Favareto, Osvaldo Milaré; Da Nóbrega Neto, Trajano Pires ; Interlando, J. Carmelo ; Palazzo Jr., Reginaldo (IEEE International Symposium on Information Theory - Proceedings, 1997) [Trabalho apresentado em evento]
Signal sets matched to the additive group of GF(p) under the Mannheim distance are constructed. Such constellations are obtained via the ring of algebraic integers of an extension K=Q(√d) of Q, Where d=-1 or d=-3. The ... -
PARAMETERS OF A POSITIVE CHAIN SEQUENCE ASSOCIATED WITH ORTHOGONAL POLYNOMIALS
Marcato, Gustavo A.; Sri Ranga, A. ; Lun, Yen Chi (Proceedings of the American Mathematical Society, 2022) [Artigo]
The objective here is to provide a new characterization of all the parameter sequences of a positive chain sequence that has been of importance in the study of orthogonal polynomials on the real line. Connection formulas ... -
An Extension of the Coherent Pair of Measures of the Second Kind on the Unit Circle
; ; Ranga, A. Sri (Operator Theory: Advances and Applications, 2021) [Capítulo de livro]
This paper deals with sequences of monic polynomials { Φn(μk;z)}n≥0, k = 0, 1, orthogonal with respect to two nontrivial Borel measures μk, k = 0, 1, supported on the unit circle, satisfying (formula presented) n ≥ 3, where ... -
Mixed orthogonality on the unit ball
Bracciali, Cleonice F.; (Computational and Applied Mathematics, 2021) [Artigo]
We consider multivariate functions satisfying mixed orthogonality conditions with respect to a given moment functional. This kind of orthogonality means that the product of functions of different parity order is computed ... -
A review of mathematical optimization models applied to the sugarcane supply chain
Teixeira, Eduardo dos Santos; Rangel, Socorro ; Florentino, Helenice de O. ; de Araujo, Silvio Alexandre (International Transactions in Operational Research, 2021) [Artigo]
Sugarcane is a product of great economic relevance and, as well as its use for the production of different types of sugar, it is also a renewable source for the production of bio-fuels, other bio-products, and electricity. ... -
Rational first integrals of the liénard equations: The solution to the poincaré problem for the liénard equations
; Pessoa, Claudio; (Anais da Academia Brasileira de Ciencias, 2021) [Artigo]
Poincaré in 1891 asked about the necessary and sufficient conditions in order to characterize when a polynomial differential system in the plane has a rational first integral. Here we solve this question for the class of ... -
Rigid centres on the center manifold of tridimensional differential systems
; Pessoa, Claudio; (Proceedings of the Royal Society of Edinburgh Section A: Mathematics, 2021) [Artigo]
Motivated by the definition of rigid centres for planar differential systems, we introduce the study of rigid centres on the center manifolds of differential systems on ℝ3. On the plane, these centres have been extensively ... -
Anisotropic 1-Laplacian problems with unbounded weights
Ortiz Chata, Juan C.; Pimenta, Marcos T. O. ; (Nonlinear Differential Equations and Applications, 2021) [Artigo]
In this work we prove the existence of nontrivial bounded variation solutions to quasilinear elliptic problems involving a weighted 1-Laplacian operator. A key feature of these problems is that weights are unbounded. One ... -
Minimax Control Problems: Optimality Conditions
Aquino, P. G.P.; ; Silva, G. N. (Procedia Computer Science, 2021) [Trabalho apresentado em evento]
The formulation of the minimax control problem is considered. We allow for parameter uncertainties in all functions involved: in the cost function, in the dynamical control system and in the equality and inequality ... -
Geometry of bifurcation sets of generic unfoldings of corank two functions
; dos Santos, Samuel Paulino (Monatshefte fur Mathematik, 2021) [Artigo]
We study the geometry of bifurcation sets of generic unfoldings of D4±-functions. Taking blow-ups, we show each of the bifurcation sets of D4±-functions admits a parametrization as a surface in R3. Using this parametrization, ... -
Necessary optimality conditions for minimax optimal control problems with mixed constraints
; ; Silva, Geraldo Nunes (ESAIM - Control, Optimisation and Calculus of Variations, 2021) [Artigo]
A weak maximal principle for minimax optimal control problems with mixed state-control equality and inequality constraints is provided. In the formulation of the minimax control problem we allow for parameter uncertainties ... -
A class of Sobolev orthogonal polynomials on the unit circle and associated continuous dual Hahn polynomials: Bounds, asymptotics and zeros
Bracciali, Cleonice F.; da Silva, Jéssica V. ; Sri Ranga, A. (Journal of Approximation Theory, 2021) [Artigo]
This paper deals with orthogonal polynomials and associated connection coefficients with respect to a class of Sobolev inner products on the unit circle. Under certain conditions on the parameters in the inner product it ... -
Stochastic adding machines based on Bratteli diagrams
Caprio, Danilo A.; Messaoudi, Ali ; (Annales de l'Institut Fourier, 2020) [Artigo]
In this paper, we define some Markov chains associated with Vershik maps on Bratteli diagrams. We study probabilistic and spectral properties of their transition operators and we prove that the spectra of these operators ...