hairy sphere

См. также в других словарях:

• Hairy ball theorem — The hairy ball theorem of algebraic topology states that there is no nonvanishing continuous tangent vector field on the sphere. If f is a continuous function that assigns a vector in R3 to every point p on a sphere such that f ( p ) is always… …   Wikipedia

• hairy ball theorem — noun a) Given a sphere covered in fur, one cannot brush all the hairs flat without creating at least two whirls b) There is no nonvanishing continuous tangent vector field on the sphere …   Wiktionary

• Wilfred the Hairy — Statue in Madrid (L. S. Carmona, 1750–53). Wilfred or Wifred, called the Hairy,[1] was Count of Urgell (870–897), Cerdanya (870–897), Barcelona (878–897), Girona (878–897), Besalú (878–897), and Ausona (886–897). He was responsible for the… …   Wikipedia

• mathematics — /math euh mat iks/, n. 1. (used with a sing. v.) the systematic treatment of magnitude, relationships between figures and forms, and relations between quantities expressed symbolically. 2. (used with a sing. or pl. v.) mathematical procedures,… …   Universalium

• Lemme de Milnor — Théorème de la boule chevelue Si un champ de vecteurs sur une sphère est symbolisé par des cheveux de longueur constante, le théorème de la boule chevelue stipule que la sphère contient au moins un épi. La figure en contient deux, un sur chaque… …   Wikipédia en Français

• Theoreme de la boule chevelue — Théorème de la boule chevelue Si un champ de vecteurs sur une sphère est symbolisé par des cheveux de longueur constante, le théorème de la boule chevelue stipule que la sphère contient au moins un épi. La figure en contient deux, un sur chaque… …   Wikipédia en Français

• Théorème de la boule chevelue — Si un champ de vecteurs sur une sphère est symbolisé par des cheveux de longueur constante, le théorème de la boule chevelue stipule que la sphère contient au moins un épi. La figure en contient deux, un sur chaque pôle …   Wikipédia en Français

• Chern class — In mathematics, in particular in algebraic topology and differential geometry, the Chern classes are characteristic classes associated to complex vector bundles. Chern classes were introduced by Shiing Shen Chern (1946). Contents 1 Basic… …   Wikipedia

• Topology — (Greek topos , place, and logos , study ) is the branch of mathematics that studies the properties of a space that are preserved under continuous deformations. Topology grew out of geometry, but unlike geometry, topology is not concerned with… …   Wikipedia

• Quaternions and spatial rotation — Unit quaternions provide a convenient mathematical notation for representing orientations and rotations of objects in three dimensions. Compared to Euler angles they are simpler to compose and avoid the problem of gimbal lock. Compared to… …   Wikipedia

• Phyrexia — is one of several fictional featured in the storyline and cards from the trading card game . It is often called the final Hell for artifacts , or simply The Nine Hells . Geography Phyrexia is an artificial plane formed from nine hollow spheres,… …   Wikipedia