Projective Planes, Coverings and a Network Problem
نویسندگان
چکیده
A problem concerning packet switched networks leads to a natural combinatorial design problem, whose solution involves (k; n)-arcs in projective planes, 3-dimensional linear codes, the theory of fractional matchings and designs which approximate projective planes.
منابع مشابه
Computation of highly ramified coverings
An almost Belyi covering is an algebraic covering of the projective line, such that all ramified points except one simple ramified point lie above a set of 3 points of the projective line. In general, there are 1-dimensional families of these coverings with a fixed ramification pattern. (That is, Hurwitz spaces for these coverings are curves.) In this paper, three almost Belyi coverings of degr...
متن کاملBranched Coverings and Minimal Free Resolution for Infinite-dimensional Complex Spaces
We consider the vanishing problem for higher cohomology groups on certain infinite-dimensional complex spaces: good branched coverings of suitable projective spaces and subvarieties with a finite free resolution in a projective space P(V ) (e.g. complete intersections or cones over finitedimensional projective spaces). In the former case we obtain the vanishing result for H. In the latter case ...
متن کاملReconstructing Projective Planes from Semibiplanes
From a projective plane Π with a homology τ of order 2, one obtains an incidence system having as points and blocks the 〈τ〉-orbits of length 2 on the points and lines of Π, and with incidence inherited from Π. The resulting structure, denoted by Π/τ , is an example of a homology semibiplane. We have shown that a Desarguesian projective plane of odd prime order is uniquely reconstructible from i...
متن کاملUpper Bounds on the Covering Number of Galois-Planes with Small Order
Our paper deals with a problem of P. Erd} os' related to the covering number of blocking sets of nite projective planes. An integer linear programming (ILP) formulation of Erd} os' problem is introduced for projective planes of given orders. The mathematical programming based approach for this problem is new in the area of nite projective planes. Since the ILP problem is NP-hard and may involve...
متن کاملCYCLIC COVERINGS OF THE p-ADIC PROJECTIVE LINE BY MUMFORD CURVES
Exact bounds for the positions of the branch points for cyclic coverings of the p-adic projective line by Mumford curves are calculated in two ways. Firstly, by using Fumiharu Kato’s ∗-trees, and secondly by giving explicit matrix representations of the Schottky groups corresponding to the Mumford curves above the projective line through combinatorial group theory.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Des. Codes Cryptography
دوره 29 شماره
صفحات -
تاریخ انتشار 2003