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Related papers: An update on a few permanent conjectures

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In 1982, Chollet conjectured that $\mathrm{per}(A\circ B)\le \mathrm{per}(A)\mathrm{per}(B)$ for Hermitian positive semidefinite matrices $A,B$, where $\circ$ denotes the Hadamard product, and observed that in the real symmetric case it…

Combinatorics · Mathematics 2026-04-28 Priyanshu Pant , Ranveer Singh

We study the existence and construction of circulant matrices $C$ of order $n\geq2$ with diagonal entries $d\geq0$, off-diagonal entries $\pm1$ and mutually orthogonal rows. These matrices generalize circulant conference ($d=0$) and…

Combinatorics · Mathematics 2019-02-05 Ondřej Turek , Dardo Goyeneche

This is both an expository and research paper where we advocate a systematic study of continuous analogues of finite partially ordered sets, convex polytopes, oriented matroids, arrangements of subspaces, finite simplicial complexes, and…

Combinatorics · Mathematics 2016-03-29 Rade T. Živaljević

We investigate the problem of when $\leq\lambda$--support iterations of $<\lambda$--complete notions of forcing preserve $\lambda^+$. We isolate a property -- {\em properness over diamonds} -- that implies $\lambda^+$ is preserved and show…

Logic · Mathematics 2007-05-23 Todd Eisworth

We discuss recent progress many problems in random matrix theory of a combinatorial nature, including several breakthroughs that solve long standing famous conjectures.

Combinatorics · Mathematics 2020-05-07 Van Vu

In this article, we give proofs on the Arnold Lagrangian intersection conjecture on the cotangent bundles, Arnold-Givental Lagrangian intersection conjecture and the Arnold fixed point conjecture.

Symplectic Geometry · Mathematics 2013-07-08 Renyi Ma

In the present paper the notion of continuous frames is introduced and some results of these frames are proved. Next, we give the concept of duals of continuous frames in Hilbert C*-modules and investigate some properties of them.

Functional Analysis · Mathematics 2023-01-24 Hadi Ghasemi , Tayebe Lal Shateri

We show that the permanent of a matrix can be written as the expectation value of a function of random variables each with zero mean and unit variance. This result is used to show that Glynn's theorem and a simplified MacMahon theorem…

Combinatorics · Mathematics 2021-06-23 Mobolaji Williams

We describe an approach to the circulant Hadamard conjecture based on Walsh-Fourier analysis. We show that the existence of a circulant Hadamard matrix of order $n$ is equivalent to the existence of a non-trivial solution of a certain…

Combinatorics · Mathematics 2014-09-26 M. Matolcsi

As part of the recent developments in infinite matroid theory, there have been a number of conjectures about how standard theorems of finite matroid theory might extend to the infinite setting. These include base packing, base covering, and…

Combinatorics · Mathematics 2012-03-06 Nathan Bowler , Johannes Carmesin

We prove several evaluations of determinants of matrices, the entries of which are given by the recurrence $a_{i,j}=a_{i-1,j}+a_{i,j-1}$, or variations thereof. These evaluations were either conjectured or extend conjectures by Roland…

Combinatorics · Mathematics 2007-05-23 Christian Krattenthaler

We use modular symmetric designs to study the existence of Hadamard matrices modulo certain primes. We solve the $7$-modular and $11$-modular versions of the Hadamard conjecture for all but a finite number of cases. In doing so, we state a…

Combinatorics · Mathematics 2015-06-12 Vivian Kuperberg

It is conjectured that Hadamard matrices exist for all orders $4t$ ($t>0$). However, despite a sustained effort over more than five decades, the strongest overall existence results are asymptotic results of the form: for all odd natural…

Combinatorics · Mathematics 2010-03-23 Warwick de Launey

In 1982 Macdonald published his now famous constant term conjectures for classical root systems. This paper begins with the almost trivial observation that Macdonald's constant term identities admit an extra set of free parameters, thereby…

Combinatorics · Mathematics 2015-09-08 Gyula Karolyi , Alain Lascoux , S. Ole Warnaar

We propose the existence of an infinite class of exact analogues of the 3x+1 conjecture for rational numbers with fixed denominators. For some other denominators, there are several attracting cycles, which exhibit scaling and covariance…

Dynamical Systems · Mathematics 2007-05-23 Barry Brent

We present here some conjectures on the diagonalizability of uniform principal bundles on rational homogeneous spaces, that are natural extensions of classical theorems on uniform vector bundles on the projective space, and study the…

Algebraic Geometry · Mathematics 2025-04-01 Roberto Muñoz , Gianluca Occhetta , Luis E. Solá Conde

In this paper, we study the class of relatively $D$-stable matrices and provide the conditions, sufficient for relative $D$-stability. We generalize the well-known Hadamard inequality, to provide upper bounds for the determinants of…

Spectral Theory · Mathematics 2022-05-24 Olga Y. Kushel

Inspired by work of McMullen, we show that any orbit of the diagonal group in the space of lattices accumulates on the set of stable lattices. As consequences, we settle a conjecture of Ramharter concerning the asymptotic behaviour of the…

Dynamical Systems · Mathematics 2016-09-28 Uri Shapira , Barak Weiss

Recently continuous rational maps between real algebraic varieties have attracted the attention of several researchers. In this paper we continue the investigation of approximation properties of continuous rational maps with values in…

Algebraic Geometry · Mathematics 2015-12-21 Wojciech Kucharz , Krzysztof Kurdyka

A matroid is sticky if any two of its extensions by disjoint sets can be glued together along the common restriction (that is, they have an amalgam). The sticky matroid conjecture asserts that a matroid is sticky if and only if it is…

Combinatorics · Mathematics 2024-08-07 Joseph E. Bonin