punctured circle
1Real projective line — In real analysis, the real projective line (also called the one point compactification of the real line, or the projectively extended real numbers ), is the set mathbb{R}cup{infty}, also denoted by widehat{mathbb{R and by mathbb{R}P^1.The symbol… …
2Torus — Not to be confused with Taurus (disambiguation). This article is about the surface and mathematical concept of a torus. For other uses, see Torus (disambiguation). A torus As the distance to th …
3Complex plane — Geometric representation of z and its conjugate in the complex plane. The distance along the light blue line from the origin to the point z is the modulus or absolute value of z. The angle φ is the argument of z. In mathematics …
4Glossary of topology — This is a glossary of some terms used in the branch of mathematics known as topology. Although there is no absolute distinction between different areas of topology, the focus here is on general topology. The following definitions are also… …
5Residue (complex analysis) — In mathematics, more specifically complex analysis, the residue is a complex number proportional to the contour integral of a meromorphic function along a path enclosing one of its singularities. (More generally, residues can be calculated for… …
6Complex logarithm — A single branch of the complex logarithm. The hue of the color is used to show the arg (polar coordinate angle) of the complex logarithm. The saturation (intensity) of the color is used to show the modulus of the complex logarithm. The page with… …
7De Rham cohomology — For Grothendieck s algebraic de Rham cohomology see Crystalline cohomology. In mathematics, de Rham cohomology (after Georges de Rham) is a tool belonging both to algebraic topology and to differential topology, capable of expressing basic… …
8Annulus (mathematics) — In mathematics, an annulus (the Latin word for little ring , with plural annuli ) is a ring shaped geometric figure, or more generally, a term used to name a ring shaped object. The adjectival form is annular (for example, an annular eclipse).The …
9United Kingdom — a kingdom in NW Europe, consisting of Great Britain and Northern Ireland: formerly comprising Great Britain and Ireland 1801 1922. 58,610,182; 94,242 sq. mi. (244,100 sq. km). Cap.: London. Abbr.: U.K. Official name, United Kingdom of Great… …
10Murder of Kitty Genovese — Kitty Genovese from the New York Times article: Thirty Eight Who Saw Murder Didn t Call the Police Born Catherine Susan Genovese July 7, 1935(1935 07 07) Brooklyn,[1 …
