All Questions
Tagged with physics linear-algebra
19
questions
4
votes
0
answers
124
views
Calculate the integral of the Slater determinant
This is a Slater determinant:
$$
s=\left|\begin{array}{ll}
\psi_{1 s}\left(r_1\right) \alpha & \psi_{1 s}\left(r_1\right) \beta \\
\psi_{1 s}\left(r_2\right) \alpha & \psi_{1 s}\left(r_2\right)...
- 1,572
1
vote
0
answers
91
views
Gaussian Matrix Model - Large N Expansion Physics with Mathematica
Update: Attempted 2nd time by replica method
I'm trying to implement basic large N expansion in Mathematica.
I'm trying to understand what this means on the fly as well.
The model I am trying to ...
- 165
-4
votes
1
answer
117
views
Constructing NxN tridiagonal block diagonal matrix with N is a variable [closed]
Hi please can someone help me writing a program of generating a tridiagonal block matrix with dimension of NxN where N is a variable can be 50, 100, 200, 300...etc , Well I don't know how I'm a ...
- 117
5
votes
0
answers
110
views
Effectivelly using Compile for calculate a Unitary transformation
I am new to Mathematica, and this is my first post, so if my question is not clear enough, I would be glad to read the comments and edit my question to add more information.
The problem
I need to ...
0
votes
1
answer
151
views
Mathematica's Plot3D function gives me a scrambled plot
When I plot the band structure of the Lieb lattice, which has the Hamiltonian given in this code, I get a scrambled plot in the output. I've tried the exact same procedure with many different lattices ...
- 11
15
votes
2
answers
1k
views
Solving "Resistance between two nodes on a grid" problem in Mathematica
In the context of resistor networks and finding the (equivalent) resistance between two arbitrary nodes, I am trying to learn how to write
a generic approach in Mathematica, generic as in an approach ...
user52181
1
vote
0
answers
119
views
Defining commutations rules over arbitrary matrix
I'm working with spin connections with Dirac gamma matrix commutator (I know, mathematica has specific ways to work with it), and I need to define the following rules;
$[\gamma_{0},\gamma_{i}]= 2 \...
- 133
8
votes
1
answer
1k
views
Solving the Schrödinger Equation by exact diagonalization
I am solving the Schrödinger equation via finite difference, via the substitution
where we are assuming $V_1 = V_N = \infty$. I solved this using Mathematica for the case that $V(x) = 0$ and get the ...
- 2,099
1
vote
1
answer
283
views
Discrete Inertia Tensor
I want to write a code that calculates the eigenvectors of the Inertia Tensor and then shows me the object and the main axis for rotation. I only consider discrete mass distribution. This is my Code ...
- 11
6
votes
1
answer
1k
views
Building Projection Operators Onto Subspaces
Intro
In quantum mechanics one uses projection operators in many problems / derivations.
At the problem at hand I need to build projection operators (matrices) onto a subspace of my Hilbert space. I ...
- 601
4
votes
1
answer
2k
views
eigenvalues of symbolic Hermitian 3X3 matrix
My question is similar to Get rid of imaginary parametric eigenvalues of a Hermitian matrix
However I find it puzzling that the situations is so complicated, since in my case I discuss only a $3\...
- 601
12
votes
1
answer
1k
views
multiplication of vector spaces
Original Question
Disclaimer: The question motivated by the product of Hilbert spaces which arises from separate degrees of freedom which a system might contain in quantum technical system.
Examples ...
- 601
2
votes
1
answer
445
views
Get rid of imaginary parametric eigenvalues of a Hermitian matrix
I have four matrices with below structures (mat1, mat2, mat3 and ...
- 4,897
3
votes
1
answer
205
views
How to reduce an expression into user-defined variables?
In the following code, I define a set of matrices. Then, I define a function that calculates the commutation relation relation between these matrices
...
user34128
0
votes
1
answer
296
views
Find all degenerate eigenvalues of a cubic equation
I have an equation that is cubic in w. The three solutions correspond to bands in a bandstructure, and are a function of wavevector ...
- 3,416