Prepublicacions del Centre de Recerca Matemàtica: Enviaments recents
Ara mostrant els elements 61-80 de 619
On the scaling behavior of the earthquake inter-time distribution: Influence of large shocks and time scales in the Omori law
We present a study of the earthquake inter-time distribution \linebreak $ D(\Delta t)$ for a California catalog in temporal periods of short duration $ T$ . We compare experimental results with theoretical predictions and ...
On the order of the triginometric diameter of the anisotropic Nikol'\''skii--Besov class in the metric of anisotropic Lorentz spaces
In this paper we estimate the order of the triginometric diameters of the anisotropic Nikol'\''skii--Besov classes in the anisotropic Lorentz space.
On the non-existence of right almost split maps
We show that, over any ring, a module $ C$ is a codomain of a~right almost split map \iff $ C$ is a finitely presented module with local endomorphism ring; thus we give an answer to a 40 years old question by M. Auslander. ...
Modelling the solidification of a power-law fluid flowing through a narrow pipe
We develop a mathematical model to simulate the solidification process of a non-Newtonian power-law fluid flowing through a circular cross-section microchannel. The initial system consists of three partial differential ...
Explicit focal basis for some planar rigid polynomial differential systems
In general the center--focus problem cannot be solved, but in the case that the singularity has purely imaginary eigenvalues there are algorithms to solving it. The present paper implements one of these algorithms for the ...
Mather invariants in groups of piecewise-linear homeomorphisms
We describe the relation between two characterizations of conjugacy in groups of piecewise-linear homeomorphisms, discovered by Brin and Squier in \cite{brin2} and Kassabov and Matucci in \cite{kama}. Thanks to the interplay ...
Mathematical modelling of phase change with a flowing thin film
This paper concerns the practical applications and modelling of Stefan problems with a flowing thin liquid layer. The modelling will be discussed in the context of two practically important scenarios, Leidenfrost (when a ...
Efficient wavelets-based valuation of synthetic CDO tranches
We present new formulae for the valuation of synthetic collateralized debt obligation (CDO) tranches under the one-factor Gaussian copula model. These formulae are based on the wavelet theory and the method used is called ...
Order reduction for an RNA virus evolution model
A mathematical or computational model in evolutionary biology should necessary combine several comparatively fast processes, which actually drive natural selection and evolution, with a very slow process of evolution. As ...
Graded C*-algebras, graded K-theory, and twisted P-graph C*-algebras
We develop methods for computing the graded $ K$ -theory of $ C^*$ -algebras as defined in terms of Kasparov theory. We establish graded versions of Pimsner'\''s six-term sequences for graded Hilbert bimodules whose left ...
Finite-size scaling of survival probability in branching processes
Branching processes pervade many models in statistical physics. We investigate the survival probability of a Galton-Watson branching process after a finite number of generations. We reveal the finite-size scaling law of ...
Data-driven prediction of thresholded time series of rainfall and SOC models
We study the occurrence of events, subject to threshold, in a representative SOC sandpile model and in high-resolution rainfall data. The predictability in both systems is analyzed by means of a decision variable sensitive ...
Estimations of the best $ M$ -term approximations of functions in the Lorentz space with constructive methods
This paper considers the Lorentz space of periodic functions of many variables with the anisotropic norm. Estimations of the best $ M$ -term \linebreak approximations of Nikol'\''ski-Besov'\''s classes in the Lorentz space ...
Contact isotropic realisations of Jacobi manifolds
This paper investigates the local and global theory of contact isotropic realisations of Jacobi manifolds, which are contact realisations of minimal dimension. These arise in the study of integrable Hamiltonian systems on ...
Nonlinear Regularization of Discontinuous Vector Fields and Singular Perturbation
We consider piecewise smooth vector fields (PSVF) defined in open sets $ M\subseteq\R^n$ with switching manifold being a smooth surface $ \Sigma$ . The PSVF are given by pairs $ X = (X_+, X_-)$ , with $ X = X_+$ in $ ...
Deviation from power law of the global seismic moment distribution
The distribution of seismic moment is of capital interest to evaluate earthquake hazard, in particular regarding the most extreme events. We make use of likelihood-ratio tests to compare the simple Gutenberg-Richter power-law ...
MULTIGRID PRECONDITIONER FOR NONCONFORMING DISCRETIZATION OF ELLIPTIC PROBLEMS WITH JUMP COEFFICIENTS
linear system arising from the piecewise linear nonconforming Crouzeix-Raviart discretization of second order elliptic problems with jump coefficients. The preconditioner uses the standard conforming subspaces as coarse ...
Geometry of infinitely presented small cancellation groups, Rapid Decay and quasi-homomorphisms
We study the geometry of infinitely presented groups satisfying the small cancelation condition $ C'\''(1/8)$ , and define a standard decomposition (called the \dec decomposition) for the elements of such groups. We use ...
Measurements of Riemannian two-disks and two-spheres
We prove that any Riemannian two-sphere with area at most $ 1$ can be continuously mapped onto a tree in a such a way that the topology of fibers is controlled and their length is less than $ 7.6$ . This result improves ...
