Browsing Matemática by Title
Now showing items 126-145 of 232
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New mixed finite element methods for natural convection with phase-change in porous media
(2019)This article is concerned with the mathematical and numerical analysis of a steady phase change problem for non-isothermal incompressible viscous flow. The system is formulated in terms of pseudostress, strain rate and ... -
Noncommutative geometry and quantization
(2000-06)We examine some recent developments in noncommutative geometry, including spin geometries on noncommutative tori and their quantization by the Shale-Stinespring procedure, as well as the emergence of Hopf algebras as a ... -
Nonnegative mixed states in Weyl–Wigner–Moyal theory
(1988-03-21)We classify the gaussian Wigner functions corresponding to mixed states and show that, unlike the case of pure states, not all nonnegative mixed states are gaussian. -
Nori fundamental gerbe of essentially finite covers and Galois closure of towers of torsors
(2019)We prove the existence of a Galois closure for towers of torsors under finite group schemes over a proper, geometrically connected and geometrically reduced algebraic stack X over a field k. This is done by describing the ... -
Notas de lógica EMALCA 2019
(2019)Estas notas fueron utilizadas en el curso Introducción a la Lógica durante la EMALCA organizada por el CIMPA en la sede del Atlántico en 2019. La lógica matemática es un área de matemática que estudia el lenguaje formal ... -
Obtención de conjuntos aproximados mediante algoritmos genéticos
(Tesis para optar al grado de Magister Scientiae en Computación. ITCR, Cartago, 1999., 1999)En términos generales, la teoría de conjuntos aproximados, propuesta por Pawlak, consiste en explorar las particiones asociadas a las relaciones de equivalencia generadas por cada subconjunto de los atributos observados, ... -
On asymptotic expansions of twisted products
(1989-12)The series development of the quantum-mechanical twisted product is studied. The series is shown to make sense as a moment asymptotic expansion of the integral formula for the twisted product, either pointwise or in the ... -
On summability of distributions and spectral geometry
(1998-01)Modulo the moment asymptotic expansion, the Cesàro and parametric behaviours of distributions at infinity are equivalent. On the strength of this result, we construct the asymptotic analysis for spectral densities arising ... -
On the approximation of a virtual coarse space for domain decomposition methods in two dimensions
(2018)A new extension operator for a virtual coarse space is presented which can be used in domain decomposition methods for nodal elliptic problems in two dimensions. In particular, a two-level overlapping Schwarz algorithm is ... -
On the Colmez conjecture for non-abelian CM fields
(2018-02-08)The Colmez conjecture relates the Faltings height of an abelian variety with complex multiplication by the ring of integers of a CM field E to logarithmic derivatives of Artin L-functions at s=0. In this paper, we prove ... -
On the kinematics of the last Wigner particle
(2019)Wigner's particle classification provides for "continuous spin" representations of the Poincaré group, corresponding to a class of (as yet unobserved) massless particles. Rather than building their induced realizations by ... -
On the one dimensional spectral Heat content for stable processes
(2016-09)This paper provides the second term in the small time asymptotic expansion of the spectral heat content of a rotationally invariant α-stable process, 0 < α ≤ 2, for the bounded interval (a, b). The small time behavior ... -
On the Ramanujan–Lodge harmonic number expansion
(2015-01-15)The aim of this paper is to extend and refine the Ramanujan–Lodge harmonic number expansion into negative powers of a triangular number. We construct a faster asymptotic series and some new sharp inequalities for the ... -
On the standard form of the Bloch equation
(1979-03)The requirement is often made in non-equilibrium statistical mechanics that a transport equation should be derived as that which governs the subdynamics relative to a (small) part of a (large) conservative dynamical ... -
On the supremum of a family of set functions
(2023)The concept of supremum of a family of set functions was introduced by M. Veraar and I. Yaroslavtsev (2016) for families of measures defined on a measurable space. We expand this concept to include families of set functions ... -
On the ultraviolet behaviour of quantum fields over noncommutative manifolds
(1999-03)By exploiting the relation between Fredholm modules and the Segal-Shale-Stinespring version of canonical quantization, and taking as starting point the first-quantized fields described by Connes' axioms for noncommutative ... -
Orbifolds are not commutative geometries
(2008)In this note we show that the crucial orientation condition for commutative geometries fails for the natural commutative spectral triple of an orbifold M/G. -
Parallel Sums and Adaptive BDDC Deluxe
(2017)There has recently been a considerable activity in developing adaptive methods for the selection of primal constraints for BDDC algorithms and, in particular, for BDDC deluxe variants. The primal constraints of a BDDC or ... -
Parameter estimates of the 2016-2017 Zika outbreak in Costa Rica: An Approximate Bayesian Computation (ABC) approach
(2019-03-28)In Costa Rica, the first known cases of Zika were reported in 2016. We looked at the 2016-2017 Zika outbreak and explored the transmission dynamics using weekly reported data. A nonlinear differential equation single-outbreak ... -
Parte prima a p del esquema fundamental en grupos sobre anillos de valuación discreta
(2020-11-17)Si X es un esquema propio, suave y conexo sobre Spec(R), para R un anillo de valuación discreta completo, dotado de una sección x: Spec(R) -> X, es posible construir los esquemas fundamentales en grupos pi_1(X,x) y ...