2009/07/31 by Edward D. Kim, Francisco Santos
Mathematics · #math.CO #math.OC #msc:52B05 #msc:52B55 #msc:90C05
paper · pdf · doi:10.1365/s13291-010-0001-8
published as Jahresbericht der Deutschen Mathematiker-Vereinigung, Volume 112(2) (June 2010), 73-98 · 28 pages, 6 figures. Many proofs have been taken out from version 2 and put into the appendix arXiv:0912.4235
arxiv created 2009/12/22 · arxiv updated 2013/10/29
The Hirsch conjecture was posed in 1957 in a letter from Warren M. Hirsch to George Dantzig. It states that the graph of a d-dimensional polytope with n facets cannot have diameter greater than n - d. Despite being one of the most fundamental, basic and old problems in polytope theory, what we know is quite scarce. Most notably, no polynomial upper bound is known for the diameters that are conjectured to be linear. In contrast, very few polytopes are known where the bound n-d is attained. This paper collects known results and remarks both on the positive and on the negative side of the conjecture. Some proofs are included, but only those that we hope are accessible to a general mathematical audience without introducing too many technicalities.