共查询到20条相似文献,搜索用时 31 毫秒
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Anton Alekseev Nariya Kawazumi Yusuke Kuno Florian Naef 《Comptes Rendus Mathematique》2017,355(2):123-127
We define a family of Kashiwara–Vergne problems associated with compact connected oriented 2-manifolds of genus g with boundary components. The problem is the classical Kashiwara–Vergne problem from Lie theory. We show the existence of solutions to for arbitrary g and n. The key point is the solution to based on the results by B. Enriquez on elliptic associators. Our construction is motivated by applications to the formality problem for the Goldman–Turaev Lie bialgebra . In more detail, we show that every solution to induces a Lie bialgebra isomorphism between and its associated graded . For , a similar result was obtained by G. Massuyeau using the Kontsevich integral. For , , our results imply that the obstruction to surjectivity of the Johnson homomorphism provided by the Turaev cobracket is equivalent to the Enomoto–Satoh obstruction. 相似文献
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Gek L. Chia 《Discrete Mathematics》2018,341(5):1359-1362
A magic square in which the entries consist of consecutive integers from is said to be self-complementary of order if the resulting square obtained from by replacing each entry by is equivalent to (under rotation or reflection). We present a new construction for self-complementary magic squares of order for each , where is a multiple of . 相似文献
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The conservative number of a graph is the minimum positive integer , such that admits an orientation and a labeling of its edges by distinct integers in , such that at each vertex of degree at least three, the sum of the labels on the in-coming edges is equal to the sum of the labels on the out-going edges. A graph is conservative if . It is worth noting that determining whether certain biregular graphs are conservative is equivalent to find integer Heffter arrays.In this work we show that the conservative number of a galaxy (a disjoint union of stars) of size is for , , and otherwise. Consequently, given positive integers , , …, with for , we construct a cyclic -cycle system of infinitely many circulant graphs, generalizing a result of Bryant, Gavlas and Ling (2003). In particular, it allows us to construct a cyclic -cycle system of the complete graph , where . Also, we prove necessary and sufficient conditions for the existence of a cyclic -cycle system of , where is a 1-factor. Furthermore, we give a sufficient condition for a subset of to be sequenceable. 相似文献
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Shi-Mei Ma 《Discrete Mathematics》2013,313(18):1816-1822
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Let be an arbitrary integral domain, let be a multiset of elements of , let be a permutation of let be positive integers such that , and for let . We are interested in the problem of finding a block matrix with spectrum and such that for . Cravo and Silva completely characterized the existence of such a matrix when is a field. In this work we construct a solution matrix that solves the problem when is an integral domain with two exceptions: (i) ; (ii) , and for some .What makes this work quite unique in this area is that we consider the problem over the more general algebraic structure of integral domains, which includes the important case of integers. Furthermore, we provide an explicit and easy to implement finite step algorithm that constructs an specific solution matrix (we point out that Cravo and Silva’s proof is not constructive). 相似文献
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Ping Sun 《Discrete Mathematics》2012,312(24):3649-3655
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Any positive matrix M partitioned in four n-by-n blocks satisfies the unitarily invariant norm inequality , where ω is the width of the numerical range of . Some related inequalities and a reverse Lidskii majorization are given. 相似文献
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For fractional Navier–Stokes equations and critical initial spaces X, one used to establish the well-posedness in the solution space which is contained in . In this paper, for heat flow, we apply parameter Meyer wavelets to introduce Y spaces where is not contained in . Consequently, for , we establish the global well-posedness of fractional Navier–Stokes equations with small initial data in all the critical oscillation spaces. The critical oscillation spaces may be any Besov–Morrey spaces or any Triebel–Lizorkin–Morrey spaces where . These critical spaces include many known spaces. For example, Besov spaces, Sobolev spaces, Bloch spaces, Q-spaces, Morrey spaces and Triebel–Lizorkin spaces etc. 相似文献
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A cyclic code is a -ary cyclic code of length , minimum Hamming distance and weight . In this paper, we investigate cyclic codes. A new upper bound on , the largest possible number of codewords in a cyclic code, is given. Two new constructions for optimal cyclic codes based on cyclic difference packings are presented. As a consequence, the exact value of is determined for any positive integer . We also obtain some other infinite classes of optimal cyclic codes. 相似文献