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Questions tagged [singular-values]

This tag is for questions relating to 'Singular Value'. The term “singular value” relates to the distance between a matrix and the set of singular matrices

1 vote
1 answer
71 views

I will write my question in the context of differential forms, but clearly this is problem can be stated much more generally. Consider the space of smooth differential $p$-forms on $\mathbb{R}^n$. ...
Sqrt2toSqrt2's user avatar
  • 1,465
3 votes
1 answer
49 views

Let $L$ be a general (possibly non-Hermitian) square matrix and define \begin{equation} A := e^{-i L}. \end{equation} I am interested in understanding how the singular values of $A$ relate to the ...
seeker's user avatar
  • 599
0 votes
0 answers
42 views

Let $\sigma_i(M)$ denote the $i$'th singular values of matrix $M$, in decreasing order: $$\sigma_1(M) \ge \sigma_2(M) \ge \dots$$ Consider the matrix product $AMB$, where it is assumed that $A,M,B$ ...
a06e's user avatar
  • 7,139
0 votes
0 answers
43 views

Let $M$ be a rectangular real matrix, and $A,B$ two diagonal real matrices with positive entries. I have two related questions: What are the singular values of $AMB$? Are they related in some way to ...
a06e's user avatar
  • 7,139
2 votes
1 answer
82 views

Let $i$ be the imaginary unit and $A,B$ be two real $m\times n$ matrices. I wonder if there are any relations between singular values of $A+Bi$ and singular values of the real matrix $C:=\begin{...
taylor's user avatar
  • 925
0 votes
1 answer
72 views

Problem: Find the value $x^*$ that minimizes the induced 2-norm $$ ||\Gamma - R(x)||_2, \; \; \Gamma \in \mathbb{R}^{2 \times 2}, \; \; R = \left( \begin{array}{cc} a + b x & -(b + ax) \\ b + ax &...
Max Herrmann's user avatar
  • 1,550
3 votes
0 answers
129 views

I am investiganting some regularity properties for vector fields on $SU(2)$ and I reduced it to obtaining lower bounds on the absolute value of the eigenvalues (which coincide with the singular values)...
Sqrt2toSqrt2's user avatar
  • 1,465
1 vote
0 answers
103 views

I'm struggling to understand something about what I saw referred to as the lower norm function and its possible relation to singular values. Let $A\in \mathbb{R}_{m\times n}$ be a matrix with $m\geq n$...
Keen-ameteur's user avatar
  • 8,566
1 vote
0 answers
102 views

If anything, it will most likely decrease. Let $A$ be a matrix with $m$ rows and $n$ columns ($m\le n$) and $\sigma_m(A)>0$. Let $A'$ be the same matrix with one row removed. Their condition ...
BaR5uk's user avatar
  • 97
1 vote
1 answer
89 views

I've not used singular before, so I hope this question is not silly or trivial. I assume I have a finite nonempty real set $\mathbb{V}\subseteq \mathbb{R}$ and a potential function $V:\mathbb{Z}^2\to \...
Keen-ameteur's user avatar
  • 8,566
7 votes
0 answers
281 views

Let $x_1, x_2,\ldots,x_d$ be $d$ independent random vectors in $\mathbb{R}^d$ with entries sampled IID from the standard normal random variable $\mathcal{N}(0,1)$. Define the $d\times d$ random ...
Yaroslav Bulatov's user avatar
0 votes
1 answer
85 views

In the 4th edition of Linear Algebra Done Right by Sheldon Axler, the Singular Value Decomposition is stated and proved on page 287. With the way the proof is constructed, shouldn't it have been split ...
Paul Ash's user avatar
  • 1,858
1 vote
1 answer
100 views

Given $\mathbf{A} \in \mathbb{C}^{n\times m}$, let $\mathbf{A}^\dagger$ denotes its Hermitian transpose and $s_1(\mathbf{A}) = \underset{\|\mathbf{x}\|=1}{\mathsf{sup}} \|\mathbf{A}\mathbf{x}\|$ be ...
vxek's user avatar
  • 221
1 vote
0 answers
54 views

I have a tall rank-$1$ matrix ${\bf Y} \in {\Bbb C}^{n \times m}$ (where $n > m$) whose singular value decomposition (SVD) is $$ {\bf Y} = \sigma_1 {\bf u} {\bf v}^\ast. $$ I add another $n \times ...
Dawson Beatty's user avatar
1 vote
0 answers
59 views

What are the singular values $J_n(\lambda)$ Jordan block of size $n$ referred to the eigenvalue $\lambda$? I know there are a lot of estimates, but for a problem with only 2 parameters $n,\lambda$ ...
Exodd's user avatar
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