Zobrazeno 1 - 10
of 247
pro vyhledávání: '"Cufi, P."'
We establish some relations between the perimeter, the area and the visual angle of a planar compact convex set. Our first result states that Crofton's formula is the unique universal formula relating the visual angle, length and area. After that we
Externí odkaz:
http://arxiv.org/abs/2404.08349
Autor:
Cufí-Cabré, Clara, Fontich, Ernest
We consider analytic maps and vector fields defined in $\mathbb{R}^2 \times \mathbb{T}^d$, having a $d$-dimensional invariant torus $\mathcal{T}$. The map (resp. vector field) restricted to $\mathcal{T}$ defines a rotation of frequency $\omega$, and
Externí odkaz:
http://arxiv.org/abs/2310.05630
Publikováno v:
Pacific J. Math. 326 (2023) 285-300
Consider a standard Cantor set in the plane of Hausdorff dimension 1. If the linear density of the associated measure $\mu$ vanishes, then the set of points where the principal value of the Cauchy singular integral of $\mu$ exists has Hausdorff dimen
Externí odkaz:
http://arxiv.org/abs/2306.05015
Here we analyze three dimensional analogues of the classical Crofton's formula for planar compact convex sets. In this formula a fundamental role is played by the visual angle of the convex set from an exterior point. A generalization of the visual a
Externí odkaz:
http://arxiv.org/abs/2303.03255
Autor:
Cufí, Julià, Donaire, Juan J.
We modify the proof of the basic lemma of a paper of Saks and Zygmund on additive functions of rectangles.
Externí odkaz:
http://arxiv.org/abs/2207.06730
Autor:
Cufí-Cabré, Clara, Llibre, Jaume
Publikováno v:
Pacific J. Math. 324 (2023) 249-263
It is well known that linear vector fields defined in $\mathbb{R}^n$ can not have limit cycles, but this is not the case for linear vector fields defined in other manifolds. We study the existence of limit cycles bifurcating from a continuum of perio
Externí odkaz:
http://arxiv.org/abs/2207.07006
We deal with integrals of invariant measures of pairs of planes in euclidean space $\mathbb{E}^3$ as considered by Hug and Schneider. In this paper we express some of these integrals in terms of functions of the visual angle of a convex set. As a con
Externí odkaz:
http://arxiv.org/abs/2104.04397
Autor:
Magalie Weber, Patrice Buche, Liliana Ibanescu, Stéphane Dervaux, Hervé Guillemin, Julien Cufi, Michel Visalli, Elisabeth Guichard, Caroline Pénicaud
Publikováno v:
npj Science of Food, Vol 7, Iss 1, Pp 1-14 (2023)
Abstract We are witnessing an acceleration of the global drive to converge consumption and production patterns towards a more circular and sustainable approach to the food system. To address the challenge of reconnecting agriculture, environment, foo
Externí odkaz:
https://doaj.org/article/9ac0e04fc67f4a88b410e09b17f3465e
Autor:
Cufí-Cabré, Clara, Fontich, Ernest
We consider a map $F$ of class $C^r$ with a fixed point of parabolic type whose differential is not diagonalizable and we study the existence and regularity of the invariant manifolds associated with the fixed point using the parameterization method.
Externí odkaz:
http://arxiv.org/abs/2010.02790
Publikováno v:
J. London Math. Soc. (2) 106 (2022), 1603-1627
Given a finite nonnegative Borel measure $m$ in $\mathbb{R}^{d}$, we identify the Lebesgue set $\mathcal{L}(V_{s}) \subset \mathbb{R}^{d}$ of the vector-valued function $$V_{s}(x) = \int_{\mathbb{R}^{d}}\frac{x - y}{|x - y|^{s + 1}} \mathrm{d}m(y), $
Externí odkaz:
http://arxiv.org/abs/2006.11046