CRM Articles: Enviaments recents
Ara mostrant els elements 341-360 de 719
Dynamics near the invariant manifolds after a Hamiltonian-Hopf bifurcation
We consider a one parameter family of 2-DOF Hamiltonian systems having an equilibrium point that undergoes a Hamiltonian-Hopf bifurcation. We briefly review the well-established normal form theory in this case. Then we ...
Unique Continuation at the Boundary for Harmonic Functions in C1 Domains and Lipschitz Domains with Small Constant
Let (Formula presented.) be a (Formula presented.) domain, or more generally, a Lipschitz domain with small local Lipschitz constant. In this paper it is shown that if u is a function harmonic in (Formula presented.) and ...
Bounds for degrees of syzygies of polynomials defining a grade two ideal
We make explicit the exponential bound on the degrees of the polynomials appearing in the Effective Quillen-Suslin Theorem, and apply it jointly with the Hilbert-Burch Theorem to show that the syzygy module of a sequence ...
About ghost transients in spatial continuous media
The impact of space on ecosystem dynamics has been a matter of debate since the dawn of theoretical ecology. Several studies have revealed that space usually involves an increase in transients’ times, promoting the so-called ...
Hardy–Littlewood-type theorems for Fourier transforms in Rd
We obtain Fourier inequalities in the weighted Lp spaces for any 1<p<∞ involving the Hardy–Cesàro and Hardy–Bellman operators. We extend these results to product Hardy spaces for p⩽1. Moreover, boundedness of the ...
Numerical integration of high-order variational equations of ODEs
This paper discusses the numerical integration of high-order variational equations of ODEs. It is proved that, given a numerical method (say, any Runge–Kutta or Taylor method), to use automatic differentiation on this ...
Novel slow–fast behaviour in an oscillator driven by a frequency-switching force
When an oscillator switches abruptly between different frequencies, there is some ambiguity in deciding how the system should be modelled at the switch. Here we describe two seemingly natural models of a switch in a simple ...
Singular cotangent models in fluids with dissipation
In this article we analyze several mathematical models with singularities where the classical cotangent model is replaced by a b-cotangent model. We provide physical interpretations of the singular symplectic geometry ...
Breakdown of Heteroclinic Connections in the Analytic Hopf-Zero Singularity: Rigorous Computation of the Stokes Constant
Consider analytic generic unfoldings of the three- dimensional conservative Hopf-zero singularity. Under open conditions on the parameters determining the singularity, the unfolding possesses two saddle-foci when the ...
Characterization of land cover-specific fire regimes in the Brazilian Amazon
Humans profoundly alter fire regimes both directly, by introducing changes in fuel dynamics and ignitions, and indirectly, by increasing the release of greenhouse gases and aerosols from fires, which can alter regional ...
On the development of a consistent mathematical model for adsorption in a packed column (and why standard models fail)
In this paper we investigate the standard one-dimensional model for adsorption of a contaminant in a packed column. Initially we focus on two mass sink models: a full nonlinear Langmuir equation, including adsorption and ...
Phase-locking patterns underlying effective communication in exact firing rate models of neural networks
Macroscopic oscillations in the brain have been observed to be involved in many cognitive tasks but their role is not completely understood. One of the suggested functions of the oscillations is to dynamically modulate ...
Simultaneous Bifurcation of Limit Cycles and Critical Periods
The present work introduces the problem of simultaneous bifurcation of limit cycles and critical periods for a system of polynomial differential equations in the plane. The simultaneity concept is defined, as well as the ...
On the singular Weinstein conjecture and the existence of escape orbits for b-Beltrami fields
Motivated by Poincaré's orbits going to infinity in the (restricted) three-body problem [see H. Poincaré, Les Méthodes Nouvelles de la Mécanique Céleste, Vol. 3 (Gauthier-Villars, 1899) and A. Chenciner, Poincaré and the ...
Finite-size scaling of human-population distributions over fixed-size cells and its relation to fractal spatial structure
Using demographic data of high spatial resolution for a region in the south of Europe, we study the population over fixed-size spatial cells. We find that, counterintuitively, the distribution of the number of inhabitants ...
Modelling temperature-dependent dynamics of single and mixed infections in a plant virus
Multiple viral infection is an important issue in health and agriculture with strong impacts on society and the economy. Several investigations have dealt with the population dynamics of viruses with different dynamic ...
Finite-time scaling for epidemic processes with power-law superspreading events
Epidemics unfold by means of a spreading process from each infected individual to a variable number of secondary cases. It has been claimed that the so-called superspreading events of the COVID-19 pandemic are governed by ...
A Central Limit Theorem for inner functions
A Central Limit Theorem for linear combinations of iterates of an inner function is proved. The main technical tool is Aleksandrov Desintegration Theorem for Aleksandrov-Clark measures. © 2022 The Authors
Evoked and transmitted culture models: Using bayesian methods to infer the evolution of cultural traits in history
A central question in behavioral and social sciences is understanding to what extent cultural traits are inherited from previous generations, transmitted from adjacent populations or produced in response to changes in ...
Hodge–de Rham numbers of almost complex 4-manifolds
We introduce and study Hodge–de Rham numbers for compact almost complex 4-manifolds, generalizing the Hodge numbers of a complex surface. The main properties of these numbers in the case of complex surfaces are extended ...
