Please use this identifier to cite or link to this item: http://hdl.handle.net/10603/4708
Title: Some Zero Sum Problems in combinatorial number theory
Researcher: Moriya, Bhavin K
Guide(s): Adhikari, S D
Keywords: Erdand#733;os-Ginzburg-Ziv Theorem
Mathematics
Upload Date: 17-Sep-2012
University: Homi Bhabha National Institute
Completed Date: 2011
Abstract: This thesis comprises of three results each of which dealt in separate chapters. First chapter is of introductory nature, as the title suggest. And the other three chapters are devoted to three different problems. Following is a brief introduction to our results. 1. Let G be any finite abelian group of rank r with invariants n1, n2, ? ? ? , nr. In other words, G = Zn1 _Zn2 _? ? ?_Znr where ni?s are integers satisfying 1 lt n1|n2| ? ? ? |nr. The Davenport constant of a group G is defined as the smallest positive integer t such that every sequence of length t of elements of G has a non-empty zero-sum subsequence. It has been conjectured by ┬┤Sliwa that, D(G) _ Pr i=1 ni. Thinking in the direction of this conjecture we have obtained the following upper bound on Davenport constant D(G), of G, D(G) _ nr+nrand#8722;1+(c(3)and#8722;1)nrand#8722;2+(c(4)and#8722;1)nrand#8722;3+? ? ?+(c(r)and#8722;1)n1+1, where c(i)?s are Alon-Dubiner constants [10] for respective i?s. Also we shall give an application of Davenport?s constant to Quadratic sieve. 2. Let G be a finite abelian group with exp(G) = e. Let s(G) (respectively, _(G)) be the minimal positive integer t with the property that any sequence S of length t of elements of G contains an e-term subsequence (respectively, a non-empty subsequence of length at most e) of S with sum zero. For the group of rank at most two this constant has been determined completely (see [45]). Looking at the problem for groups of rank greater that 2 gave rise to this result. Our problem is to determine value of s(Cr nm) under some constraints on n,m, and r. Let n,m and r be positive integers and m _ 3. Furthermore, _(Cr m ) = ar(m and#8722; 1) + 1, for some constant ar depending on r and n is a fixed integer greater than or equal to, mr(c(r)m and#8722; ar(m and#8722; r) + m and#8722; 3)(m and#8722; 1) and#8722; (m + 1) + (m + 1)(ar + 1) m(m + 1)(ar + 1) and s(Cr n ) = (ar +1)(nand#8722;1)+1. In the above lower bound on n, c(r) is the Alon-Dubiner constant. Then s(Cr nm) = (ar + 1)(nm and#8722; 1) + 1. 3. Given an abelian group G of order n, and a finite non-empty subset A of integers, the Davenport...
Pagination: 70p.
URI: http://hdl.handle.net/10603/4708
Appears in Departments:Department of Mathematical Sciences

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02_certificate.pdf26.09 kBAdobe PDFView/Open
03_declaration.pdf26.49 kBAdobe PDFView/Open
04_dedication.pdf14.41 kBAdobe PDFView/Open
05_acknowledgements.pdf28.89 kBAdobe PDFView/Open
06_abstract.pdf121.01 kBAdobe PDFView/Open
07_list of publications.pdf32.83 kBAdobe PDFView/Open
08_table of contents.pdf25.37 kBAdobe PDFView/Open
09_chapter 1.pdf185.89 kBAdobe PDFView/Open
10_chapter 2.pdf172.95 kBAdobe PDFView/Open
11_chapter 3.pdf126.99 kBAdobe PDFView/Open
12_chapter 4.pdf122.41 kBAdobe PDFView/Open
13_bibliography.pdf93.27 kBAdobe PDFView/Open


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