Group Theory sub algebra of unitary group of U(6) group.

Click For Summary

Discussion Overview

The discussion revolves around the subgroups of the unitary group U(6), specifically focusing on the identification and understanding of three proposed subgroups: U(5), SU(3), and O(6). Participants explore the relationships between these groups and the nature of their embeddings within the context of group theory.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants identify U(5), SU(3), and O(6) as subalgebras of U(6), while others clarify that these are subgroups and emphasize the need for precise definitions of their inclusions.
  • One participant provides an example of how O(n) can be embedded into O(n+1) using a specific matrix representation.
  • Multiple participants assert that there are more than three subgroups in U(6), suggesting a broader structure than initially proposed.
  • Some participants present chains of inclusions for U(6), detailing various types of subgroup relationships, but seek clarification on how these chains are derived.
  • A later reply questions the inclusion of O(3) as a subgroup of SU(3), noting the difference in determinant properties between the two groups.

Areas of Agreement / Disagreement

Participants express disagreement regarding the classification of O(3) as a subgroup of SU(3) and the number of subgroups in U(6). There is no consensus on the understanding of the subgroup relationships or the derivation of the proposed chains.

Contextual Notes

Participants note the importance of specifying inclusions and the nature of embeddings, indicating that the discussion may depend on definitions and assumptions that have not been fully articulated.

Vikas Katoch
Messages
3
Reaction score
0
TL;DR
three sub algebra of Unitary group (6) as 1. U(5).
2. SU(3)
3. O(6)
here the three chains in attachment is attached.
I want to know how these chains are understands in group theory.
three sub algebra of Unitary group (6) as 1. U(5) .
2. SU(3)
3. O(6)
here the three chains in attachment is attached.
I want to know how these chains are understands in group theory.
 

Attachments

  • IMG_20200225_211727.jpg
    IMG_20200225_211727.jpg
    62.4 KB · Views: 337
Physics news on Phys.org
Vikas Katoch said:
Summary:: three sub algebra of Unitary group (6) as 1. U(5).
2. SU(3)
3. O(6)
here the three chains in attachment is attached.
I want to know how these chains are understands in group theory.

three sub algebra of Unitary group (6) as 1. U(5) .
2. SU(3)
3. O(6)
here the three chains in attachment is attached.
I want to know how these chains are understands in group theory.
Sub groups, not sub algebras. Of course we need to specify each inclusion separately. And it is not really an inclusion in the sense of subsets, they are embeddings in the sense of monomorphisms, injective group homomorphisms.

E.g. ##O(n) \hookrightarrow O(n+1)## can be done by ##A\longmapsto \begin{bmatrix}A&0\\0&1\end{bmatrix}##.
 
Unitary group of order six U(6) having three sub groups.
How these chains are produced. sheet attached.
 

Attachments

Unitary group of order six U(6) having three sub groups.

Type 1. U(6)⊃ U(5) ⊃ O(5)⊃ O(3) ⊃ O(2)

Type 2. U(6) ⊃SU(3) ⊃ O(3) ⊃ O(2)

Type 3. U(6) ⊃O(6) ⊃ O(5) ⊃ O(3) ⊃ O(2)

How these chains are produced.
 
Vikas Katoch said:
Unitary group of order six U(6) having three sub groups.

Type 1. U(6)⊃ U(5) ⊃ O(5)⊃ O(3) ⊃ O(2)

Type 2. U(6) ⊃SU(3) ⊃ O(3) ⊃ O(2)

Type 3. U(6) ⊃O(6) ⊃ O(5) ⊃ O(3) ⊃ O(2)

How these chains are produced.
I already told you in post #2.
 
I don't think that ##O(3)## is a subgroup of ##SU(3)##. The former has elements of determinant ##\pm 1##, but ##SU(3)## only has elements of determinant ##1##.
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
733
  • · Replies 17 ·
Replies
17
Views
9K
  • · Replies 26 ·
Replies
26
Views
1K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 20 ·
Replies
20
Views
3K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 3 ·
Replies
3
Views
1K