2009/10/12 by Thomas Britz, Bård Heiseldel, Britz, Thomas +7
Computer Science · Mathematics · #FOS: Computer and information sciences #Information Theory (cs.IT) #cs.IT #math.IT
paper · pdf · doi:10.48550/arxiv.0910.2099
10 pages, 1 figure
arxiv created 2009/10/12 · arxiv updated 2009/12/01
Wei's celebrated Duality Theorem is generalized in several ways, expressed as duality theorems for linear codes over division rings and, more generally, duality theorems for matroids. These results are further generalized, resulting in two Wei-type duality theorems for new combinatorial structures that are introduced and named \em demi-matroids. These generalize matroids and are the appropriate combinatorial objects for describing the duality in Wei's Duality Theorem. A new proof of the Duality Theorem is thereby given that explains the theorem in combinatorial terms. Special cases of the general duality theorems are also given, including duality theorems for cycles and bonds in graphs and for transversals.