Cayley Tables

A Cayley Table is a multiplication table for a group. This sounds simple however some interesting patterns and things come from this.

For example take the integers modulo 3, denoted as \(\Bbb Z_3\). Let's define multiplication in the usual sense. You will find that this forms a group (you can check this).

Now writing the elements of the group out in Lexicographical order we can form a table.

×\times001122
00
11
22

Now we simply fill it in by applying the multiplication to the corresponding elements in the rows and columns in the table. You should have:

×\times001122
00000000
11001122
22002211

Now if I colour the elements lexicographically we can see a pattern emerge (more clearly).

×\times0\color{#D61F06}01\color{#20A900}12\color{#3D99F6}2
0\color{#D61F06}00\color{#D61F06}00\color{#D61F06}00\color{#D61F06}0
1\color{#20A900}10\color{#D61F06}01\color{#20A900}12\color{#3D99F6}2
2\color{#3D99F6}20\color{#D61F06}02\color{#3D99F6}21\color{#20A900}1

We can go further and assume lexicographical order (of some sort) and remove the reference rows and columns.

0\color{#D61F06}00\color{#D61F06}00\color{#D61F06}0
0\color{#D61F06}01\color{#20A900}12\color{#3D99F6}2
0\color{#D61F06}02\color{#3D99F6}21\color{#20A900}1

The interesting thing is, is that we can do this for any group and reveal some of it's symmetries and patterns.

Over the next few days I shall be releasing the coloured Cayley tables for some groups that I have generated. We shall start of with simpler groups and eventually get more complicated. But first:

The Image at the top of the post is the Cayley Table for Z17\Bbb Z_{17}

#AbstractAlgebra #GroupTheory #Patterns #Cayley

Note by A Former Brilliant Member
6 years, 11 months ago

No vote yet
1 vote

  Easy Math Editor

This discussion board is a place to discuss our Daily Challenges and the math and science related to those challenges. Explanations are more than just a solution — they should explain the steps and thinking strategies that you used to obtain the solution. Comments should further the discussion of math and science.

When posting on Brilliant:

  • Use the emojis to react to an explanation, whether you're congratulating a job well done , or just really confused .
  • Ask specific questions about the challenge or the steps in somebody's explanation. Well-posed questions can add a lot to the discussion, but posting "I don't understand!" doesn't help anyone.
  • Try to contribute something new to the discussion, whether it is an extension, generalization or other idea related to the challenge.
  • Stay on topic — we're all here to learn more about math and science, not to hear about your favorite get-rich-quick scheme or current world events.

MarkdownAppears as
*italics* or _italics_ italics
**bold** or __bold__ bold

- bulleted
- list

  • bulleted
  • list

1. numbered
2. list

  1. numbered
  2. list
Note: you must add a full line of space before and after lists for them to show up correctly
paragraph 1

paragraph 2

paragraph 1

paragraph 2

[example link](https://brilliant.org)example link
> This is a quote
This is a quote
    # I indented these lines
    # 4 spaces, and now they show
    # up as a code block.

    print "hello world"
# I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
MathAppears as
Remember to wrap math in \( ... \) or \[ ... \] to ensure proper formatting.
2 \times 3 2×3 2 \times 3
2^{34} 234 2^{34}
a_{i-1} ai1 a_{i-1}
\frac{2}{3} 23 \frac{2}{3}
\sqrt{2} 2 \sqrt{2}
\sum_{i=1}^3 i=13 \sum_{i=1}^3
\sin \theta sinθ \sin \theta
\boxed{123} 123 \boxed{123}

Comments

There are no comments in this discussion.

×

Problem Loading...

Note Loading...

Set Loading...