Special unitary group
The simply connected compact group of type A₂. Highest weights have two nonnegative Dynkin labels (p, q).
Reference properties
Representations
An irrep (p,q) has dimension (p+1)(q+1)(p+q+2)/2 and center charge p+2q modulo 3. [sources]
Topology and global form
SU(3) is simply connected; its center is generated by exp(2πi/3)I. The adjoint form is PSU(3). [sources]
In physics
Color symmetry, multiplet decompositions, weight diagrams, and global gauge structure. [sources]
A₂ Dynkin-label convention
The labels (p,q) mean λ = pω₁ + qω₂, with (1,0) the defining 3 and (0,1) its conjugate. The scalar center generator exp(2πi/3)I acts with charge p + 2q modulo 3. [sources]
The Weyl dimension product over α₁, α₂, and α₁+α₂ gives dim(p,q) = (p+1)(q+1)(p+q+2)/2. [sources]
Related objects and maps
- Related group
- Related group
- Actual real Lie algebra
- Real-form context
- Explicit homomorphism
- Explicit homomorphism
- Explicit homomorphism
Claims and sources
Each assertion has a stable identifier within this record and a source locator or derivation. Cite the dataset edition when referring to a corrected or historical claim.
Definition
3 × 3 complex unitary matrices of determinant 1
- Lie Groups and Lie AlgebrasSections 6.1–6.3: classical matrix groups and their Lie algebrasOpen source
group:su-3#definitionReal dimension
8
- Lie Groups and Lie AlgebrasSections 6.1–6.3: su(3) has real dimension 3²−1=8Open source
group:su-3#dimensionCenter
ℤ₃
- Math 210C. Centers of simply connected semisimple groupsPage 3: type A₂ center μ₃, realized by scalar matrices in SU(3)Open source
group:su-3#centerFundamental group
0
- Conrad and Landesman · Compact Lie groupsLecture 16, printed page 73: SU(n) and Sp(n) are simply connectedOpen source
group:su-3#pi1Compact
Yes
- Lie Groups and Lie AlgebrasSections 6.1–6.3: classical matrix groups and their Lie algebrasOpen source
group:su-3#compactConnected
Yes
- Conrad and Landesman · Compact Lie groupsLectures 26–28 and Appendix V: compact semisimple groups and highest weightsOpen source
- Conrad and Landesman · Compact Lie groupsLecture 16, printed page 73: SU(n) and Sp(n) are simply connectedOpen source
group:su-3#connectedRank
2
- Conrad and Landesman · Compact Lie groupsLecture 25 and Appendix T: root systems and classical root computationsOpen source
group:su-3#rankRepresentations
An irrep (p,q) has dimension (p+1)(q+1)(p+q+2)/2 and center charge p+2q modulo 3.
- Lie Groups and Lie AlgebrasSection 26.5: Weyl dimension formula, specialized to the three positive A₂ rootsOpen source
- Lie Groups and Lie AlgebrasSection 27.2: SL(n,C) fundamental representations as exterior powersOpen source
- Lecture 17: Classification of Connected Compact and Complex Reductive GroupsSection 43.1, Proposition 43.2 and Corollary 43.5: weight lattices and descent to central quotientsOpen source
group:su-3#representations-1Topology and global form
SU(3) is simply connected; its center is generated by exp(2πi/3)I. The adjoint form is PSU(3).
- Conrad and Landesman · Compact Lie groupsLectures 26–28 and Appendix V: compact semisimple groups and highest weightsOpen source
- Conrad and Landesman · Compact Lie groupsLecture 16, printed page 73: SU(n) and Sp(n) are simply connectedOpen source
- Math 210C. Centers of simply connected semisimple groupsPages 2–4: centers of simply connected groups by root-system typeOpen source
group:su-3#topology-1In physics
Color symmetry, multiplet decompositions, weight diagrams, and global gauge structure.
- Aharony, Seiberg and Tachikawa · Global gauge structureApplications to the indicated symmetry and representation categoryOpen source
group:su-3#physics-1A₂ Dynkin-label convention
The labels (p,q) mean λ = pω₁ + qω₂, with (1,0) the defining 3 and (0,1) its conjugate. The scalar center generator exp(2πi/3)I acts with charge p + 2q modulo 3.
- Lie Groups and Lie AlgebrasSection 26.5: Weyl dimension formula, specialized to the three positive A₂ rootsOpen source
- Lie Groups and Lie AlgebrasSection 27.2: SL(n,C) fundamental representations as exterior powersOpen source
- Lecture 17: Classification of Connected Compact and Complex Reductive GroupsSection 43.1, Proposition 43.2 and Corollary 43.5: weight lattices and descent to central quotientsOpen source
Premises: Fundamental modules C³ and Λ²C³ · Dynkin labels p,q
group:su-3#weight-convention-1A₂ Dynkin-label convention
The Weyl dimension product over α₁, α₂, and α₁+α₂ gives dim(p,q) = (p+1)(q+1)(p+q+2)/2.
- Lie Groups and Lie AlgebrasSection 26.5: Weyl dimension formula, specialized to the three positive A₂ rootsOpen source
- Lie Groups and Lie AlgebrasSection 27.2: SL(n,C) fundamental representations as exterior powersOpen source
- Lecture 17: Classification of Connected Compact and Complex Reductive GroupsSection 43.1, Proposition 43.2 and Corollary 43.5: weight lattices and descent to central quotientsOpen source
Premises: λ=pω₁+qω₂ · ρ=ω₁+ω₂ · Positive-root coroot pairings with ρ are 1,1,2
group:su-3#weight-convention-2Related group
group:psu-3
- Lie Groups and Lie AlgebrasSections 6.1–6.3: classical matrix groups and their Lie algebrasOpen source
group:su-3#relation-1Related group
group:su-2
- Lie Groups and Lie AlgebrasSections 6.1–6.3: classical matrix groups and their Lie algebrasOpen source
group:su-3#relation-2Actual real Lie algebra
algebra:su-3-r
- Lie Groups and Lie AlgebrasSections 6.1–6.3: classical matrix groups and their Lie algebrasOpen source
- Lecture 15: Classification of Real Forms of Semisimple Lie AlgebrasSections 41.2–41.4: compact, split, and classical real formsOpen source
group:su-3#relation-3Real-form context
real-form:su-3-r
- Lecture 15: Classification of Real Forms of Semisimple Lie AlgebrasSections 41.2–41.4: compact, split, and classical real formsOpen source
group:su-3#relation-4Explicit homomorphism
map:su-3-to-psu-3
- Math 210C. Centers of simply connected semisimple groupsPages 2–4: centers of simply connected groups by root-system typeOpen source
- Conrad and Landesman · Compact Lie groupsAppendix O, pages 231–232: fundamental groups and covering groups; Appendix V: central quotientsOpen source
- Lecture 17: Classification of Connected Compact and Complex Reductive GroupsSection 43.1, Proposition 43.2 and Corollary 43.5: weight lattices and descent to central quotientsOpen source
group:su-3#relation-5Explicit homomorphism
map:su-2-to-su-3-regular
- Haber · Spin covers and subgroup examplesProblem 5, pages 14–15: block SU(2) subgroup of SU(3)Open source
group:su-3#relation-6Explicit homomorphism
map:su-2-to-su-3-principal
- Haber · Spin covers and subgroup examplesProblem 5, pages 14–15: the irreducible three-dimensional SU(2) action and SO(3) imageOpen source
group:su-3#relation-7