Teorema Hobby-Rice

Hobby–Rice theorem In mathematics, and in particular the necklace splitting problem, the Hobby–Rice theorem is a result that is useful in establishing the existence of certain solutions. It was proved in 1965 by Charles R. Hobby and John R. Rice;[1] a simplified proof was given in 1976 por A. Pinkus.[2] The theorem Given an integer n, define a partition of the interval [0,1] as a sequence of numbers which divide the interval to {displaystyle n+1} subintervals: {displaystyle 0=z_{0}Define a signed partition as a partition in which each subinterval {estilo de exibição eu} has an associated sign {displaystyle delta _{eu}} : {displaystyle delta _{1},dotsc ,delta _{k+1}in left{+1,-1certo}} The Hobby-Rice theorem says that for every n continuously integrable functions: {estilo de exibição g_{1},dotsc ,g_{n}colon [0,1]seta longa para a direita mathbb {R} } there exists a signed partition of [0,1] de tal modo que: {soma de estilo de exibição _{i=1}^{n+1}delta _{eu}!int_{z_{i-1}}^{z_{eu}}g_{j}(z),dz=0{texto{ por }}1leq jleq n.} (em outras palavras: for each of the n functions, its integral over the positive subintervals equals its integral over the negative subintervals). Application to fair division The theorem was used by Noga Alon in the context of necklace splitting[3] dentro 1987. Suppose the interval [0,1] is a cake. There are n partners and each of the n functions is a value-density function of one partner. We want to divide the cake into two parts such that all partners agree that the parts have the same value. This fair-division challenge is sometimes referred to as the consensus-halving problem.[4] The Hobby-Rice theorem implies that this can be done with n cuts. References ^ Hobby, C. R.; Rice, J. R. (1965). "A moment problem in L1 approximation". Anais da American Mathematical Society. Sociedade Americana de Matemática. 16 (4): 665–670. doi:10.2307/2033900. JSTOR 2033900. ^ Pinkus, Alan (1976). "A simple proof of the Hobby-Rice theorem". Anais da American Mathematical Society. Sociedade Americana de Matemática. 60 (1): 82-84. doi:10.2307/2041117. JSTOR 2041117. ^ Alon, Noga (1987). "Splitting Necklaces". Avanços em Matemática. 63 (3): 247-253. doi:10.1016/0001-8708(87)90055-7. ^ F.W. Simmons and F.E. Eles são (2003). "Consensus-halving via theorems of Borsuk-Ulam and Tucker" (PDF). Ciências Sociais Matemáticas. 45: 15-25. doi:10.1016/S0165-4896(02)00087-2. Este artigo sobre análise matemática é um esboço. Você pode ajudar a Wikipédia expandindo-a. Categorias: Theorems in measure theoryFair divisionCombinatorics on wordsTheorems in analysisMathematical analysis stubs