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In mathematics, a Minkowski plane (named after Hermann Minkowski) is one of the Benz planes: Möbius plane, Laguerre plane and Minkowski plane. ==Classical real Minkowski plane== Applying the pseudo-euclidean distance on two points (instead of the euclidean distance) we get the geometry of ''hyperbolas'', because a pseudo-euclidean circle is a hyperbola with midpoint . By a transformation of coordinates , , the pseudo-euclidean distance can be rewritten as . The hyperbolas then have asymptotes parallel to the non-primed coordinate axes. The following completion (see Möbius and Laguerre planes) ''homogenizes'' the geometry of hyperbolas: : , the set of points, : ::: the set of cycles. The incidence structure is called the classical real Minkowski plane. The set of points consists of , two copies of and the point . Any line is completed by point , any hyperbola by the two points (see figure). Two points can not be connected by a cycle if and only if or . We define: Two points are (+)-parallel () if and (−)-parallel () if . Both these relations are equivalence relations on the set of points. Two points are called parallel () if or . From the definition above we find: Lemma: : *For any pair of non parallel points there is exactly one point with . : *For any point and any cycle there are exactly two points with . : *For any three points , , , pairwise non parallel, there is exactly one cycle that contains . : *For any cycle , any point and any point and there exists exactly one cycle such that , i.e. touches at point P. Like the classical Möbius and Laguerre planes Minkowski planes can be described as the geometry of plane sections of a suitable quadric. But in this case the quadric lives in projective 3-space: The classical real Minkowski plane is isomorphic to the geometry of plane sections of a hyperboloid of one sheet (not degenerated quadric of index 2). 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Minkowski plane」の詳細全文を読む スポンサード リンク
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