enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Projective plane - Wikipedia

    en.wikipedia.org/wiki/Projective_plane

    A projective plane of order N is a Steiner S(2, N + 1, N 2 + N + 1) system (see Steiner system). Conversely, one can prove that all Steiner systems of this form (λ = 2) are projective planes. The number of mutually orthogonal Latin squares of order N is at most N − 1. N − 1 exist if and only if there is a projective plane of order N.

  3. Finite geometry - Wikipedia

    en.wikipedia.org/wiki/Finite_geometry

    If any of the lines is removed from the plane, along with the points on that line, the resulting geometry is the affine plane of order 2. The Fano plane is called the projective plane of order 2 because it is unique (up to isomorphism). In general, the projective plane of order n has n 2 + n + 1 points and the same number of lines; each line ...

  4. Incidence geometry - Wikipedia

    en.wikipedia.org/wiki/Incidence_geometry

    If P is a finite set, the projective plane is referred to as a finite projective plane. The order of a finite projective plane is n = k – 1, that is, one less than the number of points on a line. All known projective planes have orders that are prime powers. A projective plane of order n is an ((n 2 + n + 1) n + 1) configuration. The smallest ...

  5. Real projective plane - Wikipedia

    en.wikipedia.org/wiki/Real_projective_plane

    It follows that the fundamental group of the real projective plane is the cyclic group of order 2; i.e., integers modulo 2. ... 12 (4): 51 – 56, doi:10.1007 ...

  6. Bruck–Ryser–Chowla theorem - Wikipedia

    en.wikipedia.org/wiki/Bruck–Ryser–Chowla_theorem

    The theorem, for example, rules out the existence of projective planes of orders 6 and 14 but allows the existence of planes of orders 10 and 12. Since a projective plane of order 10 has been shown not to exist using a combination of coding theory and large-scale computer search, [1] the condition of the theorem is evidently not sufficient for ...

  7. Lam's problem - Wikipedia

    en.wikipedia.org/wiki/Lam's_problem

    Edward Assmus presented a connection between projective planes and coding theory at the conference Combinatorial Aspects of Finite Geometries in 1970. [4] He studied the code generated by the rows of the incidence matrix of a hypothetical projective plane of order ten and derived a number of restrictive properties that such a code must satisfy.

  8. Non-Desarguesian plane - Wikipedia

    en.wikipedia.org/wiki/Non-Desarguesian_plane

    Hanfried Lenz gave a classification scheme for projective planes in 1954, [6] which was refined by Adriano Barlotti in 1957. [7] This classification scheme is based on the types of point–line transitivity permitted by the collineation group of the plane and is known as the Lenz–Barlotti classification of projective planes.

  9. Block design - Wikipedia

    en.wikipedia.org/wiki/Block_design

    For a projective plane, k is the number of points on each line and it is equal to n + 1. Similarly, r = n + 1 is the number of lines with which a given point is incident. For n = 2 we get a projective plane of order 2, also called the Fano plane, with v = 4 + 2 + 1 = 7 points and 7 lines. In the Fano plane, each line has n + 1 = 3 points and ...