Search results for "General Mathematics"

Volume growth and parabolicity

2001

Modular quintics inℙ4

2003

We will examine the arithmetic of some of the members of a pencil of symmetric quintics in projective 4-space. We will give evidence for the modularity of some of the exceptional members (even the non-rigid ones) and give a proof in one rigid case. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

A note on conjugation involutions on homotopy complex projective spaces

1986

Gibbs measures in a markovian context and dimension

2001

LORENTZ SPACES OF VECTOR-VALUED MEASURES

2003

On many-sorted algebraic closure operators

2004

A theorem of Birkhoff-Frink asserts that every algebraic closure operator on an ordinary set arises, from some algebraic structure on the set, as the corresponding generated subalgebra operator. However, for many-sorted sets, i.e., indexed families of sets, such a theorem is not longer true without qualification. We characterize the corresponding many-sorted closure operators as precisely the uniform algebraic operators. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Solving word problems algebraically in a spreadsheet environment in a primary school

2013

This paper presents some results from an investigation into the teaching of the algebraic solving of word problems in a spreadsheet environment in the sixth grade of primary school in Spain (11-12 year old pupils). The main aim of the study was to investigate whether the spreadsheet could be a mediator to the teaching of algebraic problem solving. Through the analysis of excerpts from a case study, the core of the paper is focused on two different types of the difficulties that students showed when solving problems algebraically in a spreadsheet environment.

Sur les feuilletages alg�briques de Rolle

1997

L'objet de ce travail est l'etude des feuilletages algebriques de Rolle dans \( \Bbb {R}^n \). On montre que leur restriction au complementaire d'un nombre fini de feuilles possede une structure de produit. On precise aussi la topologie de certaines de leurs feuilles.

Gabor systems and almost periodic functions

2017

Abstract Inspired by results of Kim and Ron, given a Gabor frame in L 2 ( R ) , we determine a non-countable generalized frame for the non-separable space AP 2 ( R ) of the Besicovic almost periodic functions. Gabor type frames for suitable separable subspaces of AP 2 ( R ) are constructed. We show furthermore that Bessel-type estimates hold for the AP norm with respect to a countable Gabor system using suitable almost periodic norms of sequences.

On the enhancement of diffusion by chaos, escape rates and stochastic instability

1999

We consider stochastic perturbations of expanding maps of the interval where the noise can project the trajectory outside the interval. We estimate the escape rate as a function of the amplitude of the noise and compare it with the purely diffusive case. This is done under a technical hypothesis which corresponds to stability of the absolutely continuous invariant measure against small perturbations of the map. We also discuss in detail a case of instability and show how stability can be recovered by considering another invariant measure.