Questions tagged [permanent]
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85 questions
4
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1
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Cayley transform - determinant/permanent faster computation
Let $A$ be a $0/1$ matrix in $\mathbb Z^{n\times n}$ such that $I+A$ is invertible $\bmod 3$. Consider $Q=(I-A)(I+A)^{-1}$.
Let $Det(M)$ and $Per(M)$ be determinant and permanent respectively of ...
1
vote
1
answer
201
views
Show this permanent is non-negative
$A$ is a complex matrix of order $2n\times 2n$.
$S=\sigma_x\otimes I_{n}$, where $\sigma_x$ is Pauli matrix.
Suppose we have $S^T A S=\bar{A}$, show that the permanent $per(A)$ is non-negative.
When $...
6
votes
0
answers
863
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A conjectured generalization of Marcus's inequality
Let $[n] = \{1, \dots, n\}$ and let $\sim$ be an equivalence relation on $[n]$. Then $\sim$ induces a partition of $[n]$ into equivalence classes. Let $G$ denote the product of the groups of ...
1
vote
0
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170
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Why can permanents and hafnians be viewed as partition functions?
In the description of the book "Combinatorics and Complexity of Partition Functions", by Alexander Barvinok, it is written "...The main focus of the book is on efficient ways to compute ...
1
vote
1
answer
311
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Van der Waerden conjecture and Alexandrov-Fenchel inequality
The Van der Waerden conjecture is a lower estimate of the permanent of a doubly stochastic matrix. In this article in Wikipedia it is stated that Egorychev's proof uses the Alexandrov-Fenchel ...
3
votes
2
answers
430
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An analogue of Jacobi's formula for the matrix permanent
Is there an analogoue to Jacobi's formula for the matrix permanent?
3
votes
0
answers
255
views
Do these cousins of permanents satisfy the following inequality?
Let $H$ denote an $n$ by $n$ hermitian positive semidefinite matrix. Let $G$ and $K$ be two subgroups of the symmetric group $\Sigma_n$. Define
$$ f_{G, K}(H) = \sum_{(\sigma, \tau) \in G \times K} \...
2
votes
1
answer
418
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Deciding if given number is a permanent of matrix
The permanent of an $n$-by- $n$ matrix $A=\left(a_{i j}\right)$ is defined as
$$
\operatorname{perm}(A)=\sum_{\sigma \in S_{n}} \prod_{i=1}^{n} a_{i, \sigma(i)}
$$
The sum here extends over all ...
5
votes
1
answer
373
views
A conjectural permanent identity
Let $n>1$ be an integer, and let $\zeta$ be a primitive $n$th root of unity. By $(3.4)$ of arXiv:2206.02589, $1$ and those $n+1-2s\ (s=1,\ldots,n-1)$ are all the eigenvalues of the matrix $M=[m_{jk}...
1
vote
0
answers
207
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Some $p$-adic congruences involving permutations
Motivated by my study of determinants and permanents, here I present several conjectures on $p$-adic congruences involving permutations.
As usual, we let $S_n$ be the symmetric group consisting of all ...
10
votes
1
answer
338
views
A bound for the permanent of a nonnegative matrix
Suppose $A=(a_{ij})$ is a symmetric (0,1)-matrix with 1's along the diagonal, and let $A_{ij}$ be the matrix obtained by removing the $i$-th row and $j$-th column.
Based on substantial numerical ...
7
votes
2
answers
439
views
On permanent of a square of a doubly stochastic matrix
Let $A = (a_{i,j})$ be a double stochastic matrix with positive entries. That is, all entries are positive real numbers, and each row and column sums to one. A permanent of a matrix $A = (a_{i,j})$ is ...
25
votes
2
answers
1k
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Symmetric polynomial inequality arising from the fixed-point measure of a random permutation
A somewhat strange elementary polynomial inequality came up recently in my work, and I wonder if anyone has seen other things that are reminiscent of what follows.
Given $n$ non-negative reals $a_1, ...
2
votes
0
answers
68
views
Calculating permanents via Branch and Bound
Permanents can be interpreted as counting directed cycle covers of an asymmetric graph with unit cost edge weights.
That interpretation leads to a branch and bound algorithm for calculating the ...
1
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0
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93
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On perfect matchings on planar graphs - is there a linear time deterministic algorithm?
The slides here provide a way to get a pfaffian orientation from Minimum Spanning Tree.
MST can be found in linear time if graph is planar and weights are $1$ and the slides give a linear time ...