Questions on the group-theoretic functionality of Mathematica.

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22
votes
1answer
823 views

Visualizing Rubik's Graph

After the August 2010 discovery that the diameter of the Rubik graph is 20, I wanted to make a way to visualize Rubik's graph. Since there are about $4.3 \times 10^{19}$ vertices in this graph, it is ...
12
votes
4answers
1k views

Finding elementary cycles of (directed) graphs

I need to enumerate all the simple cycles (i.e. elementary cycles where no vertex is repeated other than the starting) of a graph which has both directed and undirected edges, where we can treat the ...
10
votes
2answers
680 views

How to create a group action table with Mathematica?

Background: I want to explain the Sylow Theorems as detailed as possible, therefore I am rewriting the proof using concrete examples. Since the answers to my questions ( about Mathematica ) have ...
10
votes
2answers
245 views
8
votes
2answers
603 views

How to generate a matrix group?

I have three $7\times 7$ matrices (with real entries, lots of zeros) and I'd like to check if they generate a finite group (or, more precisely, if the group they generate is of precise order). Would ...
8
votes
1answer
203 views

$3\times 3 = 6 + \bar{3}$ in Mathematica?

Can Mathematica handle this type of algebra, which is used very frequently in e.g. particle/nuclear physics? That is, I want to decompose a product of representations (in $SU(N)$ say) into irreducible ...
6
votes
6answers
331 views

Total by a criteria

I am developing a weighted KNN algorithm. In a step, I need to do the sum of weights of each class. For example: ...
6
votes
2answers
443 views

Symmetry-finding packages

Where can I find the most up-to-date or whatever you consider to be the most useful symmetry-finding package for differential equations? I do not intend to restrict to, but would like to include ...
6
votes
2answers
408 views

Plotting All Possible Points Belonging to a Group Orbit

Given that $$X = \{(x,y,z) \in \mathbb{R}^3 |\, x^2 + y^2 + z^2 - 2(xy + xz + yz) = k\}\,,$$ where $k$ is a constant. Also given that a group $G$ is represented by $$\langle g_1,g_2,g_3|\, g_1^2 = ...
6
votes
2answers
267 views

What is the underlying algorithm for GroupElementToWord?

What algorithm is Mathematica 9 using for GroupElementToWord[group, g]?
5
votes
1answer
104 views

Create group from multiplication table

Suppose I have a multiplication table for a group. For example, m = {{1, 2, 3, 4}, {2, 3, 4, 1}, {3, 4, 1, 2}, {4, 1, 2, 3}} I would like to create a group from ...
4
votes
2answers
174 views

Standardizing a coset table via matrix manipulation

Suppose we have a group $G$ and a subgroup $H$. A coset table encodes the permutation representation of $G$ on the right cosets of $H$. When we want to use these coset tables in calculations, it is ...
4
votes
2answers
2k views

Defining a non-commutative operator algebra in Mathematica

I am trying to develop a function(s) to do some commutator algebra to compute the enveloping algebra and ideals of a Lie algebra. For example if I have $SU(2)$ algebra generated by $L_i$ ($i=1,2,3$), ...
3
votes
2answers
371 views

What is the command to find function invariant?

What is the command to find function invariant? http://demonstrations.wolfram.com/AFunctionInvariantUnderAGroupOfTransformations/ what is algorithm it use to calculate this? Edit there is a book ...
3
votes
2answers
100 views

Generating Z^*_n

I'm using Mathematica to illustrate basic number theory concepts in a graduate cryptography class. To generate elements of the multiplicative group of integers modulo $n$, i.e. $\mathbb{Z}^*_n$, I can ...
3
votes
3answers
78 views

Express block matrix in terms of matrix basis

I'm trying to construct a function that returns the multiplication table of a matrix Lie algebra. Assuming a basis of matrices, my definitions: ...
3
votes
2answers
421 views

Package for representation of groups (group theory)

I wanted to know if there is a package which allows to compute representations of a group like the definition representation, adjoint and so on (for example the Pauli matrix for $SU(2)$ if I specify ...
3
votes
1answer
114 views

Test for group isomorphism and construct automorphism groups

MMA has some support for group theory, allowing representation of any finite group as a subgroup of $S_n$. It does not seem to have a function for testing whether two finite groups are isomorphic. Is ...
3
votes
1answer
100 views

Rewrite an expression as a sum of $SU(2)$ characters?

I have an expression of the form $$q^{-3/2} t^{-7/2}[4qt^2(t + q t^2) + t^2 (q + t) (1 + q t (1 + q t))],$$ I can factor it and write it as $4((qt)^{1/2} + (qt)^{-1/2}) + (qt+1 + ...
3
votes
1answer
55 views

Change group generators?

I want to make Cayley graphs for the same group, but with different generators. Is there any way to represent a group, besides a cumbersome permutation representation or using the default Mathematica ...
3
votes
1answer
65 views

How does GroupActionBase affect the order of elements in a group?

Related (math.SE): How does the base of a group determine the “sort” of the elements in the group The help page for GroupActionBase says: A base of a group ...
2
votes
2answers
537 views

decompose a number (less than 255) in a sum of powers of 2

Is there a built in function that would take a number and decompose it into a sum of powers of 2? The numbers will be non negative less than 256. For what it's worth I'm trying to understand a paper ...
2
votes
2answers
101 views

Counting the permuted forms of a list with repeated members under a permutation group

DeleteDuplicates[Permute[{g, g, g, g, g, e, r}, AlternatingGroup[7]]] How to count number of lists automatically?
2
votes
1answer
63 views

How to distribute PermutationProduct over the sum

Assuming I have two elements of the permutation group algebra $a_1$, $a_2$ such that $a_i=\sum_{p\in S_n}\alpha_pp$, I want to define a linear product $\odot$ that distributes over the sum and pulls ...
1
vote
1answer
39 views

Symmetric group action on polynomials

I am working with polynomials in several variables with the obvious action of $S_n$. That is, given a polynomial $f$ in the variables $x_1, \dots, x_n$, a permutation $\sigma \in S_n$ acts on $f$ by ...
0
votes
2answers
61 views

I need to make and manipulate a group ( the quaternion)

I am trying to define a group and use it to defined its classes, its character table, and irreducible representations. I am having trouble finding code to define a group and use it.
0
votes
1answer
66 views

Any command for group products?

Is there any Mathematica command or well known technique to take the direct product between two symmetric/permutation groups?
0
votes
0answers
22 views

LieART package Sp branching rules [closed]

I have been trying to find several branching rules using LieART for Mathematica, more specifically from Cn to An. I have not been able to do so, with Mathematica telling me that either An is not a ...
0
votes
0answers
29 views

Can Mathematica rewrite irreps given in Dynkin Coeffs in tensor form?

Apparently, it is possible to do Young Tableaux calculations with mathematica (see the Susyno and LieART packages). A natural follow up question is then, given that one has decomposed a direct product ...
0
votes
0answers
92 views

Group theory - symmetry inequivalent sqaure matrices with PBC

I would like to obtain the symmetry inequivalent possible occupations of indistinguishable objects in a square lattice with periodic boundary conditions. Examples: 1 object in a 4 by 4 square ...