0
votes
1answer
65 views

Elliptical polarisation

In physic context one find the curve with parametrisation in t, $x=x_0\cos(t)$ and $y=y_0\cos(t+\varphi)$ with is an ellipse with equation ...
1
vote
1answer
72 views

Are there any mathematical/physical concepts or theories for dealing with a matrix in which the values are changing in a certain way?

As a matter of fact, my application scenario is a recommender system in which the interests/preferences of the users change. I have such a global user-interest matrix: the rows are the records of many ...
1
vote
0answers
87 views

Help with spinor indices

Let's have $$ \varepsilon^{\alpha \beta} = \varepsilon^{\dot {\alpha }\dot {\beta }} = \begin{pmatrix} 0 & 1 \\ -1 & 0 \end{pmatrix}^{\alpha \beta}, \quad \varepsilon^{\alpha \beta} = ...
1
vote
2answers
196 views

Matrices/physics

Hello everyone, I'm stuck on this question and help would be very much appreciated. I get particularly confused with the sign conventions when applying KCL and KVL. Somehow I have to incorporate ...
0
votes
1answer
47 views

A group of matrices satisfying a particular constraint(definition) of the group

Suppose that one wants to have a group of matrices that satisfy some constraints. (As for a similar example, Pauli matrices satisfy some particular constraints.) The constraint goes like following: ...
1
vote
1answer
314 views

Jacobian matrix normalization

I have a problem with normalization of the Jacobian matrix. There seems to be no clear method for doing it: in some literature, it has been normalized by using some characteristic length, which is ...
2
votes
1answer
259 views

Finding equivalent matrix product of a simple quantum circuit

I was reading some papers on the efficient simulation of quantum circuits where the gates are restricted to Clifford circuits (Hadamard, PHASE and CNOT gates) and was curious about the following ...
1
vote
2answers
1k views

2D elastic collision equation: How does it work?

Hey so I recently started learning physics, and came upon this wonderful site that taught me how to calculate 2D collisions between two circles. The only part I'm confused about is how the velocity ...
3
votes
0answers
167 views

What can we say about $n\times n$ invertible matrices, all elements of which are $+1$, $-1$, or $0$?

Basically, the title says it all, except for why I am asking. I'm studying a paper that I can't do justice to in a few words here. (It is not freely available on the Web, as far as I know, but I can ...
1
vote
2answers
565 views

How to configure an LED to emit white light of a certain color temperature?

I'm working on an open source hardware project for a video/photo light, and it involves a fair bit of color math. I am trying to find my way from Color Temperature (CT) in Kelvin to current values ...
1
vote
1answer
155 views

expansion of an expression

The Fokker-Planck equation for several variables is : $$\frac{\partial W}{\partial t} = L_{FP}W\qquad(1)$$ where $$L_{FP} = -\frac{\partial}{\partial x_i}D_i(\{x\})+\frac{\partial^2}{\partial x_i ...
6
votes
1answer
651 views

Fitting a parameter dependent matrix to its eigenvalues

The essence of my question is, if I have a Hermitian matrix that is linearly dependent on a set of parameters and I have an estimate of its eigenvalues, is there a "simple" way to determine the values ...