Skip to main content

All Questions

3 votes
1 answer
54 views

Completely non- normal matrix

Let $M_n(\mathbb{C})$ be the space of $n \times n$ matrices with complex entries. A matrix $N$ is said to be normal if $N^*N=NN^*$ where $N^*$ denotes the conjugate transpose of $N$. One can think of ...
Curious's user avatar
  • 973
1 vote
0 answers
33 views

Euclidean norm of a vector resulting from a matrix multiplied by an orthonormal matrix multiplied by an arbitrary vector!

Let $A \in \{0,1\}^{m\times n}$ be a binary matrix with $ m < n$, and let $U \in \mathbb{C}^{n \times n}$ be an arbitrary orthonormal matrix. Let $\sigma_{min}$ denote the smallest non-zero ...
Drimitive Watson's user avatar
0 votes
0 answers
26 views

Decomposing a complex square matrix into multiple square matrices

I am working on a problem in optics (called Multi-plane light conversion) where I am trying to find the decomposition of a target transformation (matrix) $\hat{T}\in\mathbb{C}^{(NxN)}$. The form of ...
epk's user avatar
  • 1
0 votes
1 answer
90 views

How unique is the orthogonal diagonalization of a real symmetric matrix, if we don't change the diagonal matrix of eigenvalues (no permutaiton)?

Let $A$ be a real symmetric $n\times n$ matrix, so it's orthogonally diagonalizable, i.e. there is $P\in O(n)$ so that $P^{-1}AP=P^{T}AP=D$(diagonal). I'm asking myself: how unique can $P$ be? Here ...
Learning Math's user avatar
1 vote
0 answers
36 views

How to parameterize matrices $A$ and $B$ s.t. $AB^T$ is symmetric

Question I would like to know the most general and optimal form that the $n\times n$ square matrices $A$ and $B$ must take s.t., the matrix $AB^T$ is symmetric. (e.g., $A\in GL(n)$, $B=\lambda I$ ...
Ben94's user avatar
  • 108
0 votes
1 answer
81 views

Null Space of Matrix (Linear Algebra) [closed]

I have the problem in understanding some particular case of Null Space Matrix Given (3x3 Matrix) RREF (A) = $$\pmatrix{0 & 1 & 0 \\ 0 & 0 & 1 \\ 0 & 0 & 0}$$ Why the vector of ...
Swang Syur Zi's user avatar
0 votes
0 answers
35 views

First step of SVD changes basis of domain to basis such that...

I am trying to understand Singular Value Decomposition. I have not read this explicitly, but as far as I understand it we have: $\mathbf{V}^\top$ changes the basis from the canonical/standard basis ...
Aaron's user avatar
  • 67
0 votes
0 answers
28 views

Dualization of matrix inequalities

I am studying Linear Matrix Inequalities (LMI) in Control Theory with this lecture notes: https://www.imng.uni-stuttgart.de/mst/files/LectureNotes.pdf I am at the Dualization Section (4.4.1, page 106) ...
bottomgay4maths's user avatar
2 votes
2 answers
733 views

Why do we rotate twice in SVD decomposition

I have read the related discussion and some text and get some basic ideas. Geometrical interpretations of SVD Visualization of Singular Value decomposition of a Symmetric Matrix What I don't ...
Taylor Fang's user avatar
0 votes
1 answer
336 views

Proof of existence Schur decomposition

I was reading proof of existence of Schur decomposition. I understand everything except one thing. Why submatrices like $A_2$ have same eigen value with main matrix $A$ like $\lambda_2$ ? A ...
Alireza Asgarian's user avatar
3 votes
1 answer
139 views

Normal Form of Linear Maps Between Matrices

I am looking for a reference which features the following result -- for lack a better term I will call this "normal form" (of a linear map between matrices) -- and which explores its ...
Frederik vom Ende's user avatar
0 votes
1 answer
376 views

Prove that if K(kernel matrix) is a positive semi-definite matrix, then k is a dot product: $\exists \phi$ such that $k(x,y) = \phi(x).\phi(y)$

If a kernel matrix is positive semi-definite, how can I prove there exists a $\phi$ s.t $k(x,y) = \phi(x).\phi(y)$ My method: Every real symmetric matrix can be diagonalized, so we can write: $$ K = ...
nothatcreative5's user avatar
2 votes
0 answers
149 views

How can I multiply a linear transformation by a antilinear transformation

Well, I have the following inquiry: I have an element $g \in \mathrm{O}(V)$. I know that such element can be decomposed as the sum of two operators: $$g=p_g+q_g,$$ where $p_g$ is linear and $q_g$ is ...
James Garrett's user avatar
0 votes
0 answers
45 views

Linear transformation on eigenvalues within an eigenvalue decomposition

Suppose I have a diagonalizable real matrix $A$ with the right eigenvectors $X$ and diagonal eigenvalue matrix $\Lambda$ such that $$A = X \Lambda X^{-1}.$$ (In fact in my case $A$ is symmetric so $X^{...
Alex B's user avatar
  • 43
3 votes
1 answer
194 views

Could the product of a skew-symmetric matrix and an invertible matrix be nilpotent?

Suppose that $A$ is a $d\times d$ skew-symmetric matrix, $B$ is a $d\times d$ invertible matrix and $AB$ is a nilpotent matrix. The unique example I could find is $A=O$, the null matrix. My question: ...
Jianxing's user avatar
  • 141

15 30 50 per page
1
2 3 4 5 6