Английская Википедия:Exotic affine space
Материал из Онлайн справочника
In algebraic geometry, an exotic affine space is a complex algebraic variety that is diffeomorphic to <math>\mathbb{R}^{2n}</math> for some n, but is not isomorphic as an algebraic variety to <math>\mathbb{C}^n</math>.[1][2][3] An example of an exotic <math>\mathbb C^3</math> is the Koras–Russell cubic threefold,[4] which is the subset of <math>\mathbb C^4</math> defined by the polynomial equation
- <math>\{(z_1,z_2,z_3,z_4)\in\mathbb C^4|z_1+z_1^2z_2+z_3^3+z_4^2=0\}.</math>
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