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7 votes
1 answer
305 views

Efficiently solve the Sylvester equation $AX+XA = C$ where $X$ is skew-symmetric

Is there a way (more efficient than the standard vectorization) to solve the following Sylvester equation in the skew-symmetric matrix $X$ $$AX+XA = C$$ where the matrix $A$ is symmetric positive ...
Gabi's user avatar
  • 173
1 vote
0 answers
191 views

What is the solution of the matrix equation $A X + X A' + B X B' + C = 0$ for $X$?

I know that the matrix equation $A X + X A' + C = 0$ is in the form of the time-continuous Lyapunov equation, so solving for $X$ is pretty trivial since the solution already and numeric solvers ...
Elias Frantz's user avatar
3 votes
2 answers
244 views

A problem about determinant and matrix

Suppose $a_{0},a_{1},a_{2}\in\mathbb{Q}$, such that the following determinant is zero, i.e. $ \left |\begin{array}{cccc}\\ a_{0} &a_{1} & a_{2} \\ \\ a_{2} &a_{0}+a_{1} & a_{1}+a_{...
HilbertHunnterrrD's user avatar
2 votes
1 answer
128 views

Matrix factorization for dimensional reduction similar to spectral decomposition/SVD

I have a graph clustering problem I'm working on and it basically involves finding a factorization of the adjacency matrix $A$ such that the following equations are (approximately) satisfied: $$ A \...
ecotner's user avatar
  • 123
2 votes
1 answer
556 views

How to solve a quadratic matrix equation with positive semidefinite constraint?

I have the following quadratic matrix equation: $$ XAX+X = B $$ where both $A$ and $B$ are given positive definite matrices, and $X$ is a covariance matrix and, hence, positive definite. When there is ...
lisi's user avatar
  • 101
11 votes
1 answer
619 views

Solving $AXB + X\odot C = D$

I need to solve the following equation for $X$ with $d$-by-$d$ matrices $A,B,C,D$ and Hadamard product $\odot$ $$AXB + X\odot C = D$$ Vectorizing all terms gives a solution with $O(d^6)$ complexity, ...
Yaroslav Bulatov's user avatar
0 votes
1 answer
116 views

Matrix equation of the form $C A C^\intercal = D$

Consider the following square matrix \begin{align} A = \left(\matrix{d & 0 & -\frac12 & 0 & 0 & 0 & 0 & 0 \\ 0 & d & -d+1 & -\frac12 & 0 & ...
Astor's user avatar
  • 323
2 votes
1 answer
134 views

Quadratic matrix equation for $X\in \mathbb{C}^{ n\times p}$ with Hermitian parameters

Let $A\in \mathbb{C}^{ n\times n}$ and $B \in \mathbb{C}^{p \times p}$ be Hermitian matrices with $p < n$. Find matrix $X$ such that $X^*AX=B.$ Solution in the case of positive definite $A$ and $...
Saheb's user avatar
  • 21
3 votes
2 answers
2k views

Matrix equation with Hadamard product and its own inverse involved

I know there is an almost exactly same question here but I have further specifications. So my problem is as follows: $$ \Omega^{-1}=\dfrac{1}{n}\left(\Omega\odot \mathbf{W}+\mathbf{X}'\mathbf{X}+\...
Daeyoung's user avatar
  • 133
1 vote
2 answers
1k views

Are there some algorithms to solve the diagonal matrix $X$ to the following matrix equation?

Suppose $X$ is an unknown $m \times m$ diagonal matrix. Given a scalar $0<c<1$, and a matrix $A$ of $m \times m$ size whose entries $0<A_{i,j}<1$. Are there some algorithms to find the ...
John Smith's user avatar
5 votes
2 answers
4k views

Are there any algorithms for solving nonlinear matrix equations over $\mathbb{C}$?

Are there any algorithms for solving nonlinear matrix equations over $\mathbb{C}$? I am especially interested in solving polynomial nonlinear matrix equations. For instance, let $X$ be some matrix ...
gondolf's user avatar
  • 1,503