We present a variation and generalization of a determinant evaluation of Wilf (math.CO/9809120). His result concerns a matrix whose entries are the coefficients of powers of a given power series; we replace the powers by repeated compositions and obtain similar results.
We prove that $\det A\leq 6^\frac{n}{6}$ whenever $A\in\{0,1\}^{n\times n}$ contains at most $2n$ ones. We also prove an upper bound on the determinant of matrices with the $k$-consecutive ones property, a generalisation of the consecutive ones property, where each row is allowed to have up to $k$ blocks of ones. Finally, we prove an upper bound on the determinant of a path-edge incidence matrix in a tree and use that to bound the leaf rank of a graph in terms of its order.
In this paper we confirm several conjectures of Z.-W. Sun on Hankel-type determinants for some combinatorial sequences including Franel numbers, Domb numbers and Apéry numbers. For any nonnegative integer $n$, define \begin{gather*}f_n:=\sum_{k=0}^n\binom nk^3,\ D_n:=\sum_{k=0}^n\binom nk^2\binom{2k}k\binom{2(n-k)}{n-k}, b_n:=\sum_{k=0}^n\binom nk^2\binom{n+k}k,\ A_n:=\sum_{k=0}^n\binom nk^2\binom{n+k}k^2. \end{gather*} For $n=0,1,2,\ldots$, we show that $6^{-n}|f_{i+j}|_{0\leq i,j\leq n}$ and $12^{-n}|D_{i+j}|_{0\le i,j\le n}$ are positive odd integers, and $10^{-n}|b_{i+j}|_{0\leq i,j\leq n}…
We give a new combinatorial explanation for well-known relations between determinants and traces of matrix powers. Such relations can be used to obtain polynomial-time and poly-logarithmic space algorithms for the determinant. Our new explanation avoids linear-algebraic arguments and instead exploits a classical connection between subgraph and homomorphism counts.
Determinant maximization provides an elegant generalization of problems in many areas, including convex geometry, statistics, machine learning, fair allocation of goods, and network design. In an instance of the determinant maximization problem, we are given a collection of vectors $v_1,\ldots, v_n \in \mathbb{R}^d$, and the goal is to pick a subset $S\subseteq [n]$ of given vectors to maximize the determinant of the matrix $\sum_{i \in S} v_iv_i^\top$, where the picked set of vectors $S$ must satisfy some combinatorial constraint such as cardinality constraint ($|S| \leq k$) or matroid constr…
In this paper we present a combinatorial proof of Selberg's integral formula. We start by giving a bijective proof of a Theorem about the number of topological orders of a certain related directed graph. Selberg's Integral Formula then follows by induction. This solves a problem posed by R. Stanley in 2008. Our proof is based on Andersons analytic proof of the formula. As part of the proof we show a further generalisation of the generalised Vandermonde determinant.
Sums of binomial determinants, non-intersecting lattice paths and positivity of Chern-Schwartz-MacPherson classes
我们给出了一个Chern-Schwartz-MacPherson类的正性猜想的组合解释,正如P. P. Schiffi和作者在以前的论文中所述。它转化为一个积极的性质,由二项式系数组成的p乘p行列式的总和,推广经典的Lindstrom-Gessel-Viennot定理等。我们证明了这个猜想p= 2,3。
The Hales-Jewett Theorem states that any $r$-colouring of $[m]^n$ contains a monochromatic combinatorial line if $n$ is large enough. Shelah's proof of the theorem implies that for $m = 3$ there always exists a monochromatic combinatorial lines whose set of active coordinates is the union of at most $r$ intervals. Conlon and Kamčev proved the existence of colourings for which it cannot be fewer than $r$ intervals if $r$ is odd. For $r = 2$ however, Leader and Räty showed that one can always find a monochromatic combinatorial line whose active coordinate set is a single interval. In this paper,…
Determinant identities and a generalization of the number of totally symmetric self-complementary plane partitions
我们证明了Robbins和Zeilberger(J. Combin. Theory Ser.A66(1994),17-27),通过将问题转化为行列式评估问题并评估行列式。该行列式推广了给出包含在$(2n)\times(2n)\times(2n)$盒中的所有全对称自互补平面划分的数目的行列式,并且该行列式由Andrews(J. Combin. Theory Ser.A66(1994),28-39)以及Andrews和Burge(Pacific J.Math.158(1993),1-14)来明确地计算这个数。广义行列式的评价是独立的安德鲁斯和伯奇的计算,因此,特别是构成了一个新的解决方案,这个著名的计数问题。我们还评估了一个相关的行列式,从而推广了安德鲁斯和伯格(同上)的另一个行列式的身份。cit.)。通过将我们的一些行列式恒等式转化为常数项恒等式,我们得到了几个新的常数项恒等式.
We present and prove closed form expressions for some families of binomial determinants with signed Kronecker deltas that are located along an arbitrary diagonal in the corresponding matrix. They count cyclically symmetric rhombus tilings of hexagonal regions with triangular holes. We extend a previous systematic study of these families, where the locations of the Kronecker deltas depended on an additional parameter, to families with negative Kronecker deltas. By adapting Zeilberger's holonomic ansatz to make it work for our problems, we can take full advantage of computer algebra tools for sy…
Max Planck Institute for Mathematics in the Sciences(马克斯·普朗克科学促进学会数学与科学研究所);Budapest University of Technology and Economics(布达佩斯技术与经济大学);Leipzig University(莱比锡大学)