A Survey of the Hadamard Maximal Determinant Problem
Technological University of the Shannon: Midlands Midwest(香农理工大学:米德兰中西部);Dublin City University(都柏林城市大学);Mathematical Sciences Publishers, Berkeley, CA, USA(数学科学出版社);Worcester Polytechnic Institute, MA, USA(伍斯特理工学院)
Patrick Browne, Ronan Egan, Fintan Hegarty, Padraig O Cathain
In a celebrated paper of 1893, Hadamard established the maximal determinant theorem, which establishes an upper bound on the determinant of a matrix with complex entries of norm at most $1$. His paper concludes with the suggestion that mathematicians study the maximum value of the determinant of an $n \times n$ matrix with entries in $\{ \pm 1\}$. This is the Hadamard maximal determinant problem.
This survey provides complete proofs of the major results obtained thus far. We focus equally on upper bounds for the determinant (achieved largely via the study of the Gram matrices), and constructive lower bounds (achieved largely via quadratic residues in finite fields and concepts from design theory). To provide an impression of the historical development of the subject, we have attempted to modernise many of the original proofs, while maintaining the underlying ideas. Thus some of the proofs have the flavour of determinant theory, and some appear in print in English for the first time.
We survey constructions of matrices in order $n \equiv 3 \mod 4$, giving asymptotic analysis which has not previously appeared in the literature. We prove that there exists an infinite family of matrices achieving at least $0.48$ of the maximal determinant bound. Previously the best known constant for a result of this type was $0.34$.
New Records for the Hadamard Maximal Determinant Problem
California Institute of Technology(加州理工学院);University of Cambridge(剑桥大学);London Institute for Mathematical Sciences(伦敦数学科学研究所);University of Miami(迈阿密大学);Temple University(天普大学)
Hadamard最大行列式问题要求最大的n乘n行列式,元素在{+1,-1}中。当n全等于1(mod 4)时,Farmakis和Kounias的极大过剩构造法是构造大行列式(虽然很少是极大行列式)的最成功的一般方法。然而,对于某些小的n,仍然有更大的决定因素;最近在ArXiv预印本math.CO/0304410中报道了几个新记录。在这里,我们定义了“3-正规化”n × n Hadamard矩阵,并从它们构造n+1阶的大行列式矩阵。我们的构造解释了以前的大部分“小n”记录,并在n=37,49,65,73,77,85,93和97时创造了新的记录,其中大部分都超出了最大超额技术的范围。我们猜想n=37的行列式,即72 x 9^{17} x 2^{36},达到了全局极大值。
General lower bounds on maximal determinants of binary matrices
本文给出了n乘n {+1,-1}-矩阵的极大行列式的一般下界,包括Hadamard猜想的假设和不假设.我们的界改进了de Launey和Levin(2010)的早期结果,对于n mod 4的某些同余类,改进了Koukouvinos,Mitrouli和Seberry(2000)的结果。在附录中,我们使用Jacobi行列式恒等式给出了Szölllossi(2010)关于Hadamard矩阵的子式的一个结果的新证明。
本文研究了元素为{-1,1}的奇阶矩阵的极大行列式的求法。最一般的最大行列式的上界,由于巴尔巴,只能达到时,秩序是两个连续的平方和。它是明确的,在这种情况下,总是达到的界限。除此之外,仅在第3、7、9、11、17和21阶中确立了最大值。在本文中,我们确认了这些订单的结果,并添加到列表中的第15个订单。我们遵循以前的作者在穷举搜索候选革兰氏矩阵的行列式大于或等于平方的一个已知的最大下界。然后,我们尝试将每个候选分解为{-1,1}-矩阵及其转置的乘积。对于15阶,我们找到了四个候选者,都是埃里希块形式,其中两个具有行列式(105*3^5*2^14)^2,另一个具有行列式(108*3^5*2^14)^2。前者之一分解(以一种基本上独特的方式),而其余三个不分解。这个结果证明了W. D. Smith和J. H. E.科恩我们还利用我们的方法计算了29阶、33阶和37阶极大行列式的改进的上界,并建立了9阶和1,1阶{-1,1}-矩阵的行列式函数的值域.
We describe algorithms for computing maximal determinants of binary circulant matrices of small orders. Here "binary matrix" means a matrix whose elements are drawn from $\{0,1\}$ or $\{-1,1\}$. We describe efficient parallel algorithms for the search, using Duval's algorithm for generation of necklaces and the well-known representation of the determinant of a circulant in terms of roots of unity. Tables of maximal determinants are given for orders $\le 53$. Our computations extend earlier results and disprove two plausible conjectures.
The determinants of $\{\pm 1\}$-matrices are calculated by via the oriented hypergraphic Laplacian and summing over an incidence generalization of vertex cycle-covers. These cycle-covers are signed and partitioned into families based on their hyperedge containment. Every non-edge-monic family is shown to contribute a net value of $0$ to the Laplacian, while each edge-monic family is shown to sum to the absolute value of the determinant of the original incidence matrix. Simple symmetries are identified as well as their relationship to Hadamard's maximum determinant problem. Finally, the entries…
Maximal determinants and saturated D-optimal designs of orders 19 and 37
饱和D最优设计是具有最大行列式的给定阶{+1,-1}方阵。我们搜索了19阶和37阶的饱和D最优设计,发现Smith,Cohn,Orrick和Solomon的已知矩阵是最优的.对于19阶,我们找到了所有具有最大行列式2^30 x 7^2 x 17的不等价饱和D最优设计,并确认这三个已知设计组成了一个完整的集合。对于37阶,我们证明了最大行列式是2^39 x 3^36,并找到了一个不等价的饱和D最优设计的样本。我们的方法是一个扩展的奥里克用来解决以前最小的未知顺序15;和Chadjipantelis,Kounias和Moyssiadis解决订单17和21。该方法是一个两步的计算,首先搜索候选的革兰氏矩阵,然后试图分解它们。使用类似的方法,我们也找到了13阶{+1,-1}矩阵行列式值的完整谱。
Robust Hadamard matrices, unistochastic rays in Birkhoff polytope and equi-entangled bases in composite spaces
Wydział Fizyki, Uniwersytet Warszawski(华沙大学物理系);Centrum Fizyki Teoretycznej PAN(波兰科学院理论物理中心);Instytut Fizyki im. Smoluchowskiego, Uniwersytet Jagielloński(雅盖隆大学斯莫卢霍夫斯基物理研究所)