Zero-sum problem

Zero-sum problem (Redirected from Erdős–Ginzburg–Ziv theorem) Jump to navigation Jump to search In number theory, zero-sum problems are certain kinds of combinatorial problems about the structure of a finite abelian group. Concretamente, given a finite abelian group G and a positive integer n, one asks for the smallest value of k such that every sequence of elements of G of size k contains n terms that sum to 0.

The classic result in this area is the 1961 theorem of Paul Erdős, Abraham Ginzburg, and Abraham Ziv.[1] They proved that for the group {displaystyle mathbb {Z} /nmathbb {Z} } of integers modulo n, {displaystyle k=2n-1.} Explicitly this says that any multiset of 2n − 1 integers has a subset of size n the sum of whose elements is a multiple of n, but that the same is not true of multisets of size 2n − 2. (Infatti, the lower bound is easy to see: the multiset containing n − 1 copie di 0 and n − 1 copie di 1 contains no n-subset summing to a multiple of n.) This result is known as the Erdős–Ginzburg–Ziv theorem after its discoverers. It may also be deduced from the Cauchy–Davenport theorem.[2] More general results than this theorem exist, such as Olson's theorem, Kemnitz's conjecture (proved by Christian Reiher in 2003[3]), and the weighted EGZ theorem (proved by David J. Grynkiewicz in 2005[4]).

See also Davenport constant Subset sum problem References ^ Erdős, Paolo; Ginzburg, UN.; Ziv, UN. (1961). "Theorem in the additive number theory". Toro. Res. Council Israel. 10F: 41–43. Zbl 0063.00009. ^ Nathanson (1996) p.48 ^ Reiher, cristiano (2007), "On Kemnitz' conjecture concerning lattice-points in the plane", The Ramanujan Journal, 13 (1–3): 333–337, arXiv:1603.06161, doi:10.1007/s11139-006-0256-y, S2CID 119600313, Zbl 1126.11011. ^ Grynkiewicz, D. J. (2006), "A Weighted Erdős-Ginzburg-Ziv Theorem" (PDF), Combinatorica, 26 (4): 445–453, doi:10.1007/s00493-006-0025-y, S2CID 33448594, Zbl 1121.11018. Geroldinger, Alfred (2009). "Additive group theory and non-unique factorizations". In Geroldinger, Alfred; Ruzsa, Imre Z. (eds.). Combinatorial number theory and additive group theory. Advanced Courses in Mathematics CRM Barcelona. Elsholtz, C.; Freiman, G.; Hamidoune, Y. O.; Hegyvári, N.; Károlyi, G.; Nathanson, M.; Solimosi, J.; Stanchescu, Y. With a foreword by Javier Cilleruelo, Marc Noy and Oriol Serra (Coordinators of the DocCourse). Basilea: Birkhauser. pp. 1–86. ISBN 978-3-7643-8961-1. Zbl 1221.20045. Nathanson, Melvyn B. (1996). Teoria dei numeri additivi: Inverse Problems and the Geometry of Sumsets. Testi di laurea in Matematica. vol. 165. Springer-Verlag. ISBN 0-387-94655-1. Zbl 0859.11003. link esterno "Erdős-Ginzburg-Ziv theorem", Enciclopedia della matematica, EMS Press, 2001 [1994] PlanetMath Erdős, Ginzburg, Ziv Theorem Sun, Zhi-Wei, "Covering Systems, Restricted Sumsets, Zero-sum Problems and their Unification" Categorie: CombinatoricsPaul ErdősMathematical problems