Zobrazeno 1 - 10
of 14
pro vyhledávání: '"Ricardo Uribe-Vargas"'
Publikováno v:
The Quarterly Journal of Mathematics. 73:937-967
We investigate the vertex curve, that is the set of points in the hyperbolic region of a smooth surface in real 3-space at which there is a circle in the tangent plane having at least 5-point contact with the surface. The vertex curve is related to t
Autor:
Maxim Kazarian, Ricardo Uribe-Vargas
Publikováno v:
Moscow Mathematical Journal
Moscow Mathematical Journal, Independent University of Moscow 2020, 20 (3), pp.511-530. ⟨10.17323/1609-4514-2020-20-3-511-530⟩
Moscow Mathematical Journal, Independent University of Moscow 2020, 20 (3), pp.511-530. ⟨10.17323/1609-4514-2020-20-3-511-530⟩
We define local indices for projective umbilics and godrons (also called cusps of Gauss) on generic smooth surfaces in projective 3-space. By means of these indices, we provide formulas that relate the algebraic numbers of those characteristic points
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4653eb7eb58c456e79a77fa2b48ce5a4
https://hal.archives-ouvertes.fr/hal-02568225v2/document
https://hal.archives-ouvertes.fr/hal-02568225v2/document
Autor:
Ricardo Uribe-Vargas
Publikováno v:
Journal of Singularities
Journal of Singularities, Worldwide Center of Mathematics, LLC, 2018, 17, pp.81-90. ⟨10.5427/jsing.2018.17e⟩
Journal of Singularities, Worldwide Center of Mathematics, LLC, 2018, 17, pp.81-90. ⟨10.5427/jsing.2018.17e⟩
We define a geometric invariant and an index (+1 or -1) for projective umbilics of smooth surfaces. We prove that the sum of the indices of the projective umbilics inside a connected component H of the hyperbolic domain remains constant in any 1-para
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d62cdd099a64637b788a162c7d79daf3
http://arxiv.org/abs/1911.01466
http://arxiv.org/abs/1911.01466
Autor:
Ricardo Uribe-Vargas
Publikováno v:
Functional Analysis and Other Mathematics. 1:71-83
Given positive integers a and n with (a,n)=1, we consider the Fermat–Euler dynamical system \(\hat{a}\) defined by the multiplication by a acting on the set of residues modulo n relatively prime to n. Given an integer M>1, the integers n for which
Autor:
Ricardo Uribe-Vargas
Publikováno v:
Bulletin des Sciences Mathématiques. 130:377-402
We study and develop a very new object introduced by V.I. Arnold: a monad is a triple consisting of a finite set, a map from that finite set to itself and the monad graph which is the directed graph whose vertices are the elements of the finite set a
Autor:
Ricardo Uribe-Vargas
Publikováno v:
Bulletin of the Brazilian Mathematical Society, New Series. 36:285-307
The focal curve of an immersed smooth curve γ : θ ↦ γ (θ), in Euclidean space ℝm+1, consists of the centres of its osculating hyperspheres. This curve may be parametrised in terms of the Frenet frame of γ (t, n1, . . . , n m ), as Cγ (θ) =
Autor:
Ricardo Uribe-Vargas
Publikováno v:
Mathematical Physics, Analysis and Geometry. 7:223-237
We prove that the vertices of a curve γ⊂R n are critical points of the radius of the osculating hypersphere. Using Sturm theory, we give a new proof of the (2k+2)-vertex theorem for convex curves in the Euclidean space R 2k . We obtain a very prac
Autor:
Ricardo Uribe-Vargas
Publikováno v:
Journal of Geometry. 77:184-192
We discuss three classes of closed curves in the Euclidean space $\mathbb{R}^{3}$ which have non-vanishing curvature and at least 4 flattenings (points at which the torsion vanishes). Calling these classes (de.ned below) Barner, Segre and Caratheodor
Autor:
Ricardo Uribe-Vargas
Publikováno v:
Journal of Geometry and Physics. 45:91-104
To any co-oriented curve (front) in the two-dimensional sphere S 2 we associate a rigid body motion together with an instantaneous axis of rotation. We prove that the pair of (antipodal) curves on the sphere determined by the instantaneous axis of ro
Autor:
Ricardo Uribe-Vargas
Publikováno v:
Comptes Rendus Mathematique. 335:47-52
A smooth closed curve in R P n is called convex if any hyperplane intersects it in at most n points, taking multiplicities into account. A convex curve has no flattening and its osculating hyperplane intersects it only at the point of osculation. A c