Search results for "Euler"
showing 9 items of 159 documents
Del álgebra a la geometría : la sistematización de las coordenadas cartesianas y la representación gráfica de funciones en la Introductio in analysin…
2012
Este trabajo de investigación explora la presentación del sistema de coordenadas cartesianas en la Introductio in Analysin Infinitorum de Euler y en los libros de texto de Lacroix Traité du calcul différentiel et du calcul intégral and Traité Élémentaire de Trigonométrie Rectiligne et Sphérique, et d’Application de l’Algèbre a la Géométrie, indagando qué componentes hicieron posible su sistematización, y teniendo presente las dificultades de los estudiantes en el uso de las coordenadas cartesianas. Es un hecho harto conocido que los estudiantes tienen dificultades en la comprensión y el uso de la representación de funciones en el sistema de coordenadas cartesianas (SCC). Esta problemática d…
Human capital and the intertemporal substitution for leisure: empirical evidence for Spain
2022
AbstractIn this paper we provide the first estimate of the intertemporal substitution for leisure in Spain, accounting for the impact of human capital accumulation. This would allow uncovering whether the intertemporal labour supply of Spanish workers is affected by human capital. Our empirical strategy consists of estimating the equation for the intertemporal substitution of leisure with and without accounting for human capital, what allows to detect hypothetical estimation biases associated to omitting the impact of human capital. To that end, we build a pseudo-panel data set combining the Spanish Family Expenditure Survey and the Labour Survey over the period 1987–1997. While the model t…
Convergence rate of the Euler scheme for diffusion processes
2006
Saddle index properties, singular topology, and its relation to thermodynamic singularities for aϕ4mean-field model
2004
We investigate the potential energy surface of a ${\ensuremath{\phi}}^{4}$ model with infinite range interactions. All stationary points can be uniquely characterized by three real numbers ${\ensuremath{\alpha}}_{+},{\ensuremath{\alpha}}_{0},{\ensuremath{\alpha}}_{\ensuremath{-}}$ with ${\ensuremath{\alpha}}_{+}+{\ensuremath{\alpha}}_{0}+{\ensuremath{\alpha}}_{\ensuremath{-}}=1$, provided that the interaction strength $\ensuremath{\mu}$ is smaller than a critical value. The saddle index ${n}_{s}$ is equal to ${\ensuremath{\alpha}}_{0}$ and its distribution function has a maximum at ${n}_{s}^{\mathrm{max}}=1∕3$. The density $p(e)$ of stationary points with energy per particle $e$, as well as…
New Invariant Domain Preserving Finite Volume Schemes for Compressible Flows
2021
We present new invariant domain preserving finite volume schemes for the compressible Euler and Navier–Stokes–Fourier systems. The schemes are entropy stable and preserve positivity of density and internal energy. More importantly, their convergence towards a strong solution of the limit system has been proved rigorously in [9, 11]. We will demonstrate their accuracy and robustness on a series of numerical experiments.
$$\mathscr {K}$$-Convergence of Finite Volume Solutions of the Euler Equations
2020
We review our recent results on the convergence of invariant domain-preserving finite volume solutions to the Euler equations of gas dynamics. If the classical solution exists we obtain strong convergence of numerical solutions to the classical one applying the weak-strong uniqueness principle. On the other hand, if the classical solution does not exist we adapt the well-known Prokhorov compactness theorem to space-time probability measures that are generated by the sequences of finite volume solutions and show how to obtain the strong convergence in space and time of observable quantities. This can be achieved even in the case of ill-posed Euler equations having possibly many oscillatory s…
An explicit unconditionally stable numerical solution of the advection problem in irrotational flow fields
2004
[1] A new methodology for the Eulerian numerical solution of the advection problem is proposed. The methodology is based on the conservation of both the zero- and the first-order spatial moments inside each element of the computational domain and leads to the solution of several small systems of ordinary differential equations. Since the systems are solved sequentially (one element after the other), the method can be classified as explicit. The proposed methodology has the following properties: (1) it guarantees local and global mass conservation, (2) it is unconditionally stable, and (3) it applies second-order approximation of the concentration and its fluxes inside each element. Limitati…
Champs de vecteurs analytiques commutants, en dimension 3 ou 4: existence de zeros communs
1992
One proves the existence of a common zero for any two ℝ-analytic commuting vector fields on a 4-dimensional manifold with not zero Euler characteristic. A local version of this result remains true on 3-manifolds.