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The rank of a matrix expression

I'm studying discrete-time LTI systems and state estimators for them. Recently, I studied this paper. I am facing a matrix rank calculation problem and having trouble solving it. I will provide more ...
Mostafa - Free Palestine's user avatar
0 votes
0 answers
53 views

Relations between the optimal solutions of two related SDPs

In system theory, we often encounter Semi-Definite Programs (SDPs) with Linear Matrix Inequality (LMI) constraints, such as those presented in this paper. I have introduced new variables based on the ...
Mostafa - Free Palestine's user avatar
1 vote
1 answer
67 views

Low rank matrices which preserve maximizers of quadratic form

Suppose $x, y \in \{0,1\}^d$ are binary vectors. For a matrix $M$ consider the quadratic form, \begin{align} x^T M y + (\mathbb{1} - x)^T M (\mathbb{1} - y) \end{align} Does there exist an $M$ such ...
Television's user avatar
2 votes
0 answers
72 views

Gradient descent over the set of complex symmetric matrices

In the course of my research (somewhat related to compressive sensing), I am trying to determine a complex, symmetric matrix $L$ (i.e. $L = L^T$) through the following optimization formulation: $$ \...
Shreyas B.'s user avatar
0 votes
1 answer
134 views

Existence of cyclic subspace decompositions for pairs of commuting matrices

Let $\mathbb{K}$ be an arbitrary field (possibly finite). Let $V$ be a finite-dimensional vector space over $\mathbb{K}$, and let $A,B$ be two linear endomorphisms of $V$ which commute. For $v\in V$, ...
Abdelmalek Abdesselam's user avatar
1 vote
1 answer
519 views

Optimal transport between two matrices

I'm investigating the use of optimal transport to define a distance between non-negative matrices that satisfy the condition $\mathbf e^\top\mathbf M\mathbf e = 1$ (i.e., the sum of all elements in ...
Peyman's user avatar
  • 243
1 vote
2 answers
69 views

Monotonicity of kernel matrices with respect to hyperparameters

Let $\mathcal{X}$ be some nice space, let $\Phi$ be some ordered space, and let $K :\mathcal{X} \times \mathcal{X} \times \Phi \to \mathbf{R}$ be a positive-semidefinite kernel indexed by a ...
πr8's user avatar
  • 801
1 vote
0 answers
49 views

Bounds on Eigenvalues After Skew-Symmetric Perturbation

Consider two matrices $\mathbf{J} \in \mathbb{R}^{n \times n}$ and $\mathbf{L} = -\mathbf{L}^T \in \mathbb{R}^{n \times n}$. I am trying to upper bound the eigenvalues of their sum: $$\mathbf{A} = \...
Leo's user avatar
  • 11
1 vote
3 answers
345 views

How to optimize for the best fit nonuniform-scale-rotation to a given 3×3 matrix?

Given a matrix $L\in \mathbb{R}^{3 \times 3}$, I'm looking for a method to find the closest (in a least squares sense) product of a non-uniform scaling matrix and a rotation matrix: $$ \min_{s\in\...
Alec Jacobson's user avatar
3 votes
2 answers
246 views

$\min(\det(\mathbf{A}))$ for special matrix $\mathbf{A}$

(The construction of matrix $\mathbf{A}$ is not difficult to be understood. You can first jump to A Toy Example to take a glance. Any idea or suggestion would be appealing for me.) The Original ...
BinChen's user avatar
  • 133
5 votes
2 answers
343 views

Maximal eigenvalue of a correlation matrix with some entries fixed as zeros

Let $A$ be real a positive semidefinite matrix of dimension $n$ and with $1$s on the diagonal. Those matrices are sometimes referred to as correlation matrices. From the positivity of the minors, we ...
user479369's user avatar
0 votes
0 answers
159 views

Double summation of matrices as constraints in convex optimization in CVX

I want to implement the following optimization problem from the following paper Randomized Gossip Algorithms, Page 10 Eq 53: \begin{align} \text{minimize} &\qquad s\\ \text{subject to} & \...
Spring Breeze's user avatar
4 votes
1 answer
228 views

A question on eigenvalue of parametric matrix

Is there a way to efficiently check if all matrices in the following set are Hurwitz stable (eigenvalues strictly in the left-hand plane)?$$\left\{ A \in \Bbb R^{n \times n} : \ell_{i,j}\leq A_{i,j} \...
DSM's user avatar
  • 1,216
3 votes
1 answer
255 views

Minimizing quadratic objective under orthogonality constraints

The following problem is motivated from Generalized Procrustes Analysis. I am wondering if it is possible to obtain a closed form minimizer (which may involve SVD or some other decomposition of a ...
Dhruv Kohli's user avatar
8 votes
2 answers
380 views

Projecting onto space of matrices with spectral radius less than one

Consider the space $$ S = \left\{ A \in \mathbb{R}^{n \times n} : \mathrm{SpectralRadius}(|A|) \leq 1 \right\}$$ where $|A|$ is the entry-wise absolute value. Given a matrix $M \in \mathbb{R}^{n\times ...
CComp's user avatar
  • 123
1 vote
1 answer
1k views

Prove that absolute value of eigenvalue is smaller than 1 [closed]

I want to prove that the absolute value of the eigenvalues of a matrix A are smaller than 1 for $$A=\left(\begin{array}{cc} 0 & -H_{11}^{-1} H_{12} \\ -H_{22}^{-1} H_{21} & 0 \end{array}\right)...
anonymousguyfromtheworld's user avatar
0 votes
0 answers
46 views

Lipschitz solutions to linear complementarity problems (LCP)

Let $M\in\mathbb{R}^{n\times n}$. For $q\in\mathbb{R}^n$, define the set: $$S_M(q)=\{y\in\mathbb{R}^n|y\ge 0,q+My\ge 0, y^\top (q+My)=0\}.$$ This is the set of solutions to the LCP $(q,M)$. We say $...
cfp's user avatar
  • 183
0 votes
0 answers
193 views

Rewriting Kronecker product

im considering a pole placement problem in control theory and my controler has a specific form: $$R=I_n\otimes q$$ where $I_n$ is the identitiy matrix of size $n$ and $q\in\Re^k$ is a vector of the ...
BigL's user avatar
  • 1
1 vote
0 answers
78 views

Is there an efficient way to do semidefinite programming with a Lyapunov equation constraint?

I am trying to numerically solve semidefinite programs of the form $$\begin{array}{ll} \underset{X,Y}{\text{minimize}} & \operatorname{tr}(AX)\\ \text{subject to} & BY + YB = X\\ & X, Y \...
henrikr's user avatar
  • 31
0 votes
2 answers
1k views

Matrix norm minimization and matrix inner product

One of the famous problem in SDP is the matrix norm minimization (see S. Boyd, Convex Optimization, p. 170). Consider: \begin{equation}\label{eq:Lasse} \begin{aligned} &\min_{\mathbf{x}} & &...
sleeve chen's user avatar
0 votes
0 answers
113 views

Reference for matrix Lyapunov function / matrix dynamic system / stability

We usually consider $\dot{x} = f(x)$, where $x$ is a vector. Now, I want to consider $$\dot{X}=f(X,U),$$ where $X$ is a square matrix $\mathbb{R}^{n\times n}$ state, $U$ is a square matrix variable $\...
Denny's user avatar
  • 101
2 votes
1 answer
139 views

linear programming with $n$ choose $r$ variables

Given parameters $r < n$, define $m = {n \choose r}$ and let $A$ be the $n\times m$ matrix whose columns are all the vectors with $r$ $1$'s and $n-r$ $0$'s. Let $b$ be a positive $n$-vector. Is ...
David T.'s user avatar
1 vote
2 answers
87 views

Stability of linear controller in the presence of a lag

Consider the following equation: $\ddot{x} = -a x - b \dot{x}$ which we interpret as saying that we are trying to control $x$ by setting $\ddot{x}$. We can rewrite this with $X = \begin{bmatrix} ...
Bernard 's user avatar
1 vote
0 answers
514 views

Minimizing the Frobenius norm of a quadratic matrix expression

Given matrices $R \in \mathbb R^{m \times n}$ and $Y \in \mathbb R^{p \times n}$, where $R$ is full rank, how can I solve the following optimization problems? $$\min_{X \in \mathbb R^{p \times m}} \| ...
见得哆啦's user avatar
0 votes
1 answer
194 views

Optimization problem involving matrix

I am struggling to solve an optimization problem of the following form: $$\begin{array}{ll} \underset{A}{\text{maximize}} & \log \det (A) \\ \text{subject to} & a^T A^{-1} a \le b\end{array}$$ ...
user164237's user avatar
5 votes
1 answer
261 views

Bounds on number of "non-metric" entries in matrices

Question: what upper bounds are known on the number of non-metric entries of finite dimensional square matrices $\boldsymbol{A}\in\mathbb{R}^{n\times n}$ with strictly positive off-diagonal elements $...
Manfred Weis's user avatar
  • 13.2k
4 votes
1 answer
254 views

Max-norm projection of a Hermitian matrix onto the set of positive semidefinite matrices

For a given Hermitian matrix $A$ (i.e. complex matrix with $A_{ij}^{\ast}=A_{ji}$) find its max-norm projection onto the set of complex positive semi-definite matrices: $$\Pi(A)=\mathrm{argmin}_{M\...
user157498's user avatar
0 votes
0 answers
95 views

How to maximum L1 norm problem?

I have met a problem these days. \begin{equation} \underset{\omega}{\max} \quad \Vert \text{diag}(\mathbf{h}^H)\mathbf{G}^H\mathbf{\omega}\Vert_1 \\ s.t.\quad\mathbf{\omega}^H\mathbf{G}\mathbf{G}^H\...
fengbiqian's user avatar
2 votes
1 answer
536 views

Minimize matrix norm over the unitary matrices

Suppose $C_1$ and $C_2$ are some fixed $n \times n$ matrices. Define the norm $\| M \| = \sum_{i = 1}^n \max_j |M_{ij}|$. What is $\min_U \|C_1 U C_2 \|$? Here $U$ ranges over the $n \times n$ unitary ...
Gautam's user avatar
  • 1,703
1 vote
0 answers
152 views

solving a non-linear Matrix equation

I am working on a problem of optimization of wireless sensor networks in order to achieve the optimal power allocation in the network. I find an equality matrix problem that can be written as ...
hichem hb's user avatar
  • 377
5 votes
1 answer
335 views

Projecting a symmetric matrix onto the space of linear operators with a particular eigenvalue

Specifically, I am interested in the case where one eigenvalue is exactly $0$. Given an $n \times n$ symmetric matrix, I would like to find the closest $n\times n$ symmetric matrix that has one ...
Him's user avatar
  • 245
2 votes
1 answer
497 views

Does the Perron vector maximize $x^TAx$ in the simplex?

Let $\mathbf{A}$ be any $n\times n$ symmetric positive matrix ($A_{ij}>0$). It is easy to show that the solution to the following optimization problem \begin{align} \max_{\mathbf{x}}~~\mathbf{x^...
dineshdileep's user avatar
  • 1,421
1 vote
1 answer
877 views

Minimization problem involving the inverse of an affine matrix function

I want to minimize $v^T (A+I+UQU^*)^{-1} v$, subject to $Q$ and $A$ being positive semi-definite and ${\rm trace}(Q)<1$. Here, $v$ is a given vector with unit norm, that is, $\|v\|_2=1$.
hichem hb's user avatar
  • 377
3 votes
0 answers
111 views

Approximate inverse of large sparse matrix

Given a large sparse matrix $M$, how to determine the existence of a good preconditioner? In other words, does there exist a sparse matrix $X$ such that $X M$ is close to the identity with respect to ...
Jianqiang Li's user avatar
1 vote
2 answers
143 views

Controllability Gramian asymptotics for small times

Set-up. Consider the following linear controlled system $$ \dot{y}(t) = A y(t) + B u (t), \ \ t \in [0,T], \ \ \ \ \ \ \ \ \ \ (1) $$ where $y$ is the state of the system, $y(t) \in R ^n$, $A \in R ...
Viktor B's user avatar
  • 724
0 votes
1 answer
135 views

Solving Problem: LMIs and block matrices

I have been reading through this paper (https://ieeexplore.ieee.org/document/7995739) where I am stuck with this particular LMI. If you are familiar with control theory, the author is trying to find ...
Zero's user avatar
  • 103
4 votes
0 answers
249 views

Is every stable matrix orthogonally similar to a $D$-skew-symmetric matrix?

Let $\mathrm{diag}(A)$ denote the diagonal matrix with diagonal entries of $A\in\mathbb{R}^{n\times n}$ and let $\succeq$ denote the standard partial order in the cone of (symmetric) positive definite ...
Ludwig's user avatar
  • 2,712
12 votes
2 answers
799 views

A (linear) optimization problem subject to (linear) matrix inequality constraints

Let $A \in \mathbb{R}^{n \times n}$ be a Hurwitz matrix, i.e. $A$ satisfies $\mathrm{Re}\,\lambda_i< 0$, where $\{\lambda_i\}_{i=1}^n$ is the set of eigenvalues of $A$. Suppose that the trace of $A$...
Ludwig's user avatar
  • 2,712
2 votes
0 answers
248 views

A parametrization of stable matrices

Let $A\in\mathbb{R}^{n\times n}$ be a diagonalizable matrix with real and strictly negative eigenvalues. Furthermore, suppose that $\mathrm{tr}(A)=-1$. My question. I'm wondering whether it is ...
Ludwig's user avatar
  • 2,712
3 votes
0 answers
243 views

An inequality concerning the solution of a Lyapunov equation

Let $A$ be an Hurwitz stable matrix (i.e. the real part of the eigenvalues of $A$ lie in the left-half plane) and $Q$ be a positive semidefinite matrix ($Q\ge 0$, for short). Let $P>0$ be the ...
Ludwig's user avatar
  • 2,712
9 votes
2 answers
684 views

A trace-constrained maximization problem in the cone of positive definite matrices

Let $A\in\mathbb{R}^{n\times n}$ be a matrix having eigenvalues with strictly negative real part (in other words, $A$ is supposed to be Hurwitz stable). Let $\mathrm{tr}(\cdot)$ denote the trace ...
Ludwig's user avatar
  • 2,712
1 vote
0 answers
163 views

Bounds of Procrustes problem

We denote $\|\cdot\|_F$ as the Frobenius norm of some matrix. We define $f: \mathbb{R}^{d\times r}\times\mathbb{R}^{d\times r} \rightarrow \mathbb{R}^{d\times r}$ as the following: \begin{align} f(A,B)...
FFFenor94's user avatar
1 vote
2 answers
307 views

How to solve this system of Matrix equations? (Coupled riccati equations?)

I am trying to solve for K in the following problem: $ 3I = A_1 + A_2 + A_3$ $ A_1 K A_1 = K_1 $ $ A_2 K A_2 = K_2 $ $ A_3 K A_3 = K_3 $ Where $I$ is the identity, $K, K_1, K_2, K_3, A_1, A_2, ...
Gab's user avatar
  • 13
8 votes
5 answers
481 views

Nearest matrix orthogonally similar to a given matrix

Given $A,B\in\Bbb R^{n\times n}$ is there technique find $$\min_{ T\in O(n,\Bbb R)}\|A-TBT^{-1}\|_F\mbox{ or }\min_{ T\in O(n,\Bbb R)}\|A-TBT^{-1}\|_2$$ within additive approximation error in $\...
Turbo's user avatar
  • 13.9k
3 votes
2 answers
2k views

Proving that a matrix is positive semidefinite

Let matrices $A, B$ be positive semidefinite. Can we prove that $A(I+BA)^{-1}$ is positive semidefinite?
user121234's user avatar
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
4 votes
1 answer
289 views

A property of positive matrices

Let $\mathbb{S}^{dn} \ni X \succeq 0$ with $d,n \in \mathbb{N}$, where $X \succeq 0$ indicates that $X$ is positive semidefinite. Now partition $X$ into the block form \begin{gather} \begin{pmatrix} ...
Johannes's user avatar
1 vote
1 answer
313 views

Nonlinear low-rank approximation - corrected

I would like to state that this is related to a past question of mine which contained errors and now appears in the corrected form, with the erroneous one deleted and closed. In my research of linear ...
groupoid's user avatar
  • 620
1 vote
1 answer
124 views

Possible analytical way to solve or approximate a specific optimization problem's solution

In my research on linear algebra and optimization, I have come across the following problem repeatedly: Given constant matrices $C\in\mathbb{R}^{k \times k}$ and $X\in\mathbb{R}^{n \times n}$, $$\...
groupoid's user avatar
  • 620
0 votes
1 answer
134 views

Modification of a known optimization problem

In my research of linear algebra and optimization, I wish to modify the following well-known problem: $ \min \lVert x-Ax \rVert$ subject to $ rank(A)\leq k $ where $ x $ is a given column vector ...
groupoid's user avatar
  • 620