Zobrazeno 1 - 10
of 46
pro vyhledávání: '"Francisco Fontenele"'
Autor:
Ahlers, Guenter, Calzavarini, Enrico, Araujo, Francisco Fontenele, Funfschilling, Denis, Grossmann, Siegfried, Lohse, Detlef, Sugiyama, Kazuyasu
Publikováno v:
Phys. Rev. E 77, 046302 (2008)
As shown in earlier work (Ahlers et al., J. Fluid Mech. 569, p.409 (2006)), non-Oberbeck Boussinesq (NOB) corrections to the center temperature in turbulent Rayleigh-Benard convection in water and also in glycerol are governed by the temperature depe
Externí odkaz:
http://arxiv.org/abs/0712.0079
Publikováno v:
Phys. Rev. Lett. 95, 084502 (2005)
The phenomenon of irregular cessation and subsequent reversal of the large-scale circulation in turbulent Rayleigh-B\'enard convection is theoretically analysed. The force and thermal balance on a single plume detached from the thermal boundary layer
Externí odkaz:
http://arxiv.org/abs/nlin/0407031
We review recent studies demonstrating a nonuniversal (continuously variable) survival exponent for history-dependent random walks, and analyze a new example, the hard movable partial reflector. These processes serve as a simplified models of infecti
Externí odkaz:
http://arxiv.org/abs/cond-mat/0304292
Publikováno v:
Phys. Rev. E 66, 051102 (2002)
We study an unbiased, discrete time random walk on the nonnegative integers, with the origin absorbing. The process has a history-dependent step length: the walker takes steps of length v while in a region which has been visited before, and steps of
Externí odkaz:
http://arxiv.org/abs/cond-mat/0206281
Publikováno v:
Revista Matemática Iberoamericana.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::ef4f9459daa6393cbe96114e0f800a3d
https://doi.org/10.4171/rmi/1407
https://doi.org/10.4171/rmi/1407
Publikováno v:
Proceedings of the Royal Society of Edinburgh: Section A Mathematics. 152:1081-1088
We prove that there are no regular algebraic hypersurfaces with non-zero constant mean curvature in the Euclidean space $\mathbb {R}^{n+1},\,\;n\geq 2,$ defined by polynomials of odd degree. Also we prove that the hyperspheres and the round cylinders
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0e1576b32b0734a618e7d876f0ce94eb
https://doi.org/10.1017/prm.2021.49
https://doi.org/10.1017/prm.2021.49
Publikováno v:
The Journal of Geometric Analysis. 31:5687-5720
Let $$M^n$$ be a complete n-dimensional Riemannian manifold and $$\Gamma _f$$ the graph of a $$C^2$$ -function f defined on a metric ball of $$M^n$$ . In the same spirit of the estimates obtained by Heinz for the mean and Gaussian curvatures of a sur
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::a416ca6e650d56330fc54ad971f35212
https://doi.org/10.1007/s12220-020-00497-w
https://doi.org/10.1007/s12220-020-00497-w
Autor:
Francisco Fontenele, Frederico Xavier
Publikováno v:
Revista Matemática Iberoamericana. 35:2035-2052
By the Poincare–Hopf theorem, every ovaloid has at least one umbilic. In this paper we extend this result to the more general case of complete positively curved surfaces in R3 whose shape operator A satisfies inf |A|>0 and sup |∇A
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::751d1a69e1f33181aa857d71273915e4
https://doi.org/10.4171/rmi/1109
https://doi.org/10.4171/rmi/1109
A special case of the main result states that a complete $1$-connected Riemannian manifold $(M^n,g)$ is isometric to one of the models $\mathbb R^n$, $S^n(c)$, $\mathbb H^n(-c)$ of constant curvature if and only if every $p\in M^n$ is a non-degenerat
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::aa2330c59e7c7cdb3230e0c8ded6704e
Autor:
Francisco Fontenele, Frederico Xavier
Publikováno v:
L’Enseignement Mathématique. 61:139-149
It is shown that if a $C^2$ surface $M\subset\mathbb R^3$ has negative curvature on the complement of a point $q\in M$, then the $\mathbb Z/2$-valued Poincar\'e-Hopf index at $q$ of either distribution of principal directions on $M-\{q\}$ is non-posi
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d6a146b67dd742d96a30902f18a53047
https://doi.org/10.4171/lem/61-1/2-6
https://doi.org/10.4171/lem/61-1/2-6