Questions tagged [hurwitz-matrices]

A square matrix $A$ is a Hurwitz matrix if all eigenvalues of $A$ have strictly negative real parts.

38 questions
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Is there a homeomorphism between the sets of Schur stable and Hurwitz stable matrices in companion forms?

The set of Schur stable matrices is \begin{align*} \mathcal S = \{A \in M_n(\mathbb R): \rho(A) < 1\}, \end{align*} where $\rho(\cdot)$ denotes the spectral radius of a matrix and the set of Hurwitz stable matrices is \begin{align*} \mathcal H =…
user1101010
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Checking if one "special" kind of block matrix is Hurwitz

I have the next block matrix $$ J = \begin{bmatrix}A & B \\ K &0\end{bmatrix} $$ all matrices are square, where $A < 0$ (definite negative), $B$ has all its eigenvalues with positive real part being $A = - (B + B^T)$, and $K$ is a diagonal…
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A problem about positive definite matrices

Given $A\in\mathbb{R}^{n\times n}$, show that all eigenvalues of A has negative real part if and only if for each positive definite matrix $C\in\mathbb{R}^{n\times n}$, there exists an unique positive definite matrix $B\in\mathbb{R}^{n\times n}$…
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If $A$ Hurwitz, $(A+A^*)$ is Hurwitz?

If I have $A$ Hurwitz matrix, is $(A+A^*)$, with $A^*$ the transpose of $A$, still Hurwitz? Any reference or proof? Because if $(A+A^*)$ is still Hurwitz I can say that it is even negative definite being symmetric and with real eigenvalues negative.
4
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Condition for eigenvalues to have negative real parts (Hurwitz) for specific matrix structure

Let $$ A=\begin{bmatrix} P & \alpha x\\ -y^\top & 0\end{bmatrix}$$ where $P \in \mathbb{R}^{n \times n}$ is Hurwitz (the eigenvalues of $P$ have strictly negative real parts), $x, y \in \mathbb{R}^{n}$, and $\alpha$ is a real positive scalar. Find…
3
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Find all stable dynamical systems in 2 variables

- To set jargon: The set of all $2\times2$ real matrices is $\mathbb{R}^4$. The 4 matrix elements fully parametrise this set: if we see this set as a manifold, then the 4 parameters are coordinates (we can always change coordinates and find another…
3
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3 answers

Is the linear interpolation of two stable matrices always stable?

I have a question regarding the stability of linear systems. Let's assume we have two stable linear systems represented by matrices $A_1$ and $A_2$, where both matrices have eigenvalues with strictly negative real parts (i.e., both systems are…
3
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1 answer

Check if block matrix is Hurwitz

How can I conclude from that fact, that $K_0$ and $K_1$ are positive definite diagonal matrices, that $$ A = \left( \begin{matrix} 0 & I \\ -K_0 & -K_1\end{matrix} \right) $$ is Hurwitz? Here, $I$ is the identity matrix and the dimension of all…
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1 answer

Randomly generate Hurwitz matrices?

Recall that a Hurwitz matrix is one whose eigenvalues lie in the left half plane; strictly Hurwitz such that they are in the strict left half plane. Is there way to randomly generate Hurwitz matrices? I came up with two methods, Randomly sample…
3
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Hurwitz matrix and positive definiteness

Hurwitz Matrices require that for a polynomial to have all negative real part roots then the determinant of the principle minors must be positive. I know that if we have a positive definite matrix then all the real parts of the eigenvalues are…
3
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1 answer

Common quadratic Lyapunov function with all convex combinations Hurwitz

I have two $n\times n$ Hurwitz stable matrices, so $A_i\in H_n$ for $i=1,2$. I also know that every possible convex combination of these two matrices is Hurwitz, i.e., \begin{equation} C(A_1,A_2) = cA_1+(1-c)A_2 \in H_n \hspace{0.5cm} \forall…
3
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2 answers

Does subtracting a positive semi-definite diagonal matrix from a Hurwitz matrix keep it Hurwitz?

I am having a linear algebra problem here. I will be grateful if someone can help me. Let $A\in \mathbb{R}^{n\times n}$ be Hurwitz and diagonizable, and let $B$ be a diagonal matrix whose diagonal elements are non-negative. Is $A-B$ still…
2
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1 answer

Can the matrix product $PA$ be skew-symmetric with $P=P^T>0$ and $A$ Hurwitz?

Let a real (square) matrix $\mathbf A$ is Hurwitz (i.e., all the eigenvalues of $\mathbf A$ have negative real parts). And let $\mathbf P$ is a real symmetric positive definite matrix. What will be the condition(s) (if at all) for the product…
2
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1 answer

Is this matrix block matrix Hurwitz for some $c_1, c_2, c_3 > 0$?

Given the next well partitioned real squared matrix $$ M = \begin{bmatrix}A & \frac{c_3}{c_1}BC^T \\ c_3c_2C & E- c_3^2\frac{c_2}{c_1}CC^T\end{bmatrix}, $$ where $A$ is Hurwitz (all the eigenvalues have negative real part), $CC^T$ positive definite,…
user51196
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How to determine whether all real parts of the eigenvalues of a complex matrix are negative?

It is well-known with respect to Routh-Hurwitz Criterion that for an arbitrary matrix $A$ with real coefficients, one can derive a series of analytic expressions with these real coefficients, so as to determine whether all real parts of eigenvalues…
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