Примеры использования Projective planes на Английском языке и их переводы на Русский язык
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Generalized 3-gons are projective planes.
Gluing two projective planes creates the Klein bottle.
All finite generalized polygons except the projective planes.
Both the seven-point and 13-point projective planes have representations of this type.
The construction also works over finite fields,providing examples in finite projective planes.
By gluing together projective planes successively we get non-orientable surfaces of higher demigenus.
Every finite generalized polygon except the projective planes is a near polygon.
The only extendable projective planes(symmetric 2-(n2+ n+ 1, n+ 1, 1) designs) are those of orders 2 and 4.
There are many other examples that have been found, including most Hilbert modular surfaces,fake projective planes, Barlow surfaces, and so on.
Hanfried Lenz gave a classification scheme for projective planes in 1954 and this was refined by Adriano Barlotti in 1957.
The projective planes defined from finite fields of order p lead to K2,2-free graphs with n p2+ p+ 1 and with(p2+ p+ 1)(p+ 1) edges.
Generalized n-gons encompass as special cases projective planes(generalized triangles, n 3) and generalized quadrangles n 4.
The projective planes PG(2, K) for any field(or, more generally, for every division ring(skewfield) isomorphic to its dual) K are self-dual.
The following are important examples of symmetric 2-designs:Finite projective planes are symmetric 2-designs with λ 1 and order n> 1.
In this simplest of the projective planes, there are also seven lines; each point is on three lines, and each line contains three points.
Some of the basic concepts and terminology arises from geometric examples,particularly projective planes and affine planes. .
This is most significant for projective planes due to the universal validity of Desargues' theorem in higher dimensions.
The possible lattices have been classified by Prasad and Yeung and the classification was completed by Cartwright andSteger who checked that they actually correspond to fake projective planes.
Between 7 and 12 exist as finite projective planes, and either 14 or 15 exist as infinite projective planes.
The theorem of Desargues is valid in all projective spaces of dimension not 2, that is, all the classical projective geometries over a field(or division ring), butDavid Hilbert found that some projective planes do not satisfy it.
One can similarly construct projective planes over any other finite field, with the Fano plane being the smallest.
Bearing in mind that the geometric dimension of the projective space P(V) associated to V is dim V- 1 and that the geometric dimension of any subspace is positive, the basic proposition of incidence in this setting can take the form: linear subspaces L andM of projective space P meet provided dim L+ dim M≥ dim P. The following sections are limited to projective planes defined over fields, often denoted by PG(2, F), where F is a field.
However, dimension two has affine and projective planes that are not isomorphic to Galois geometries, namely the non-Desarguesian planes. .
Since projective planes are known to exist for all orders n which are powers of primes, these constructions provide infinite families of symmetric configurations.
Incidence structures that are most studied are those thatsatisfy some additional properties(axioms), such as projective planes, affine planes, generalized polygons, partial geometries and near polygons.
The problem of listing all fake projective planes is reduced to listing all subgroups of appropriate index of an explicitly given lattice associated to each class.
Configurations may be studied either as concrete sets of points and lines in a specific geometry,such as the Euclidean or projective planes(these are said to be realizable in that geometry), or as a type of abstract incidence geometry.
There are exactly 50 fake projective planes classified up to isometry and hence 100 distinct fake projective planes classified up to biholomorphism.
By extending these calculations Cartwright& Steger(2010)showed that the twenty-eight classes exhaust all possibilities for fake projective planes and that there are altogether 50 examples determined up to isometry, or 100 fake projective planes up to biholomorphism.
Two fake projective planes are defined to be in the same class if their fundamental groups are both contained in the same maximal arithmetic subgroup of automorphisms of the unit ball.