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Finite groups · Family

PSU(n,q)\mathrm{PSU}(n,q)Projective special unitary finite simple groups

Exclude (n,q) = (3,2); q is the fixed-field size, not the matrix-field size.

Classification coverageFinite simple classification
Definition

The determinant-one isometries of a nondegenerate Hermitian form over F(q²), modulo scalar matrices.

Definition sources

Parameter domain

Exclude (n,q) = (3,2); q is the fixed-field size, not the matrix-field size.

ParameterAllowed values
ninteger n ≥ 3
qq = p^f, with p prime and f ≥ 1
Classification sources and conventions

Reference properties

PropertyValueEvidence
Parameter domainn: integer n ≥ 3; q: q = p^f, with p prime and f ≥ 1Sources
Scope and restrictionsExclude (n,q) = (3,2); q is the fixed-field size, not the matrix-field size.Sources
Orderq^[n(n−1)/2] · ∏ᵢ₌₂ⁿ(qⁱ−(−1)ⁱ) / gcd(n,q+1)Sources

Exceptions and identifications

n = 2: PSU(2,q) ≅ PSL(2,q); these are indexed in the linear family. [sources]

(3,2): PSU(3,2) has order 72 and is not simple. [sources]

(4,2): PSU(4,2) ≅ PSp(4,3). [sources]

Names and aliases

Uₙ(q) · ²Aₙ₋₁(q)

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Claims and sources

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Definition

The determinant-one isometries of a nondegenerate Hermitian form over F(q²), modulo scalar matrices.

family:finite-unitary#definition
Parameter domain

n: integer n ≥ 3; q: q = p^f, with p prime and f ≥ 1

family:finite-unitary#parameters
Scope and restrictions

Exclude (n,q) = (3,2); q is the fixed-field size, not the matrix-field size.

family:finite-unitary#restriction
Order

q^[n(n−1)/2] · ∏ᵢ₌₂ⁿ(qⁱ−(−1)ⁱ) / gcd(n,q+1)

family:finite-unitary#order-formula
Exceptions and identifications

n = 2: PSU(2,q) ≅ PSL(2,q); these are indexed in the linear family.

family:finite-unitary#exceptions-1
Exceptions and identifications

(3,2): PSU(3,2) has order 72 and is not simple.

family:finite-unitary#exceptions-2
Exceptions and identifications

(4,2): PSU(4,2) ≅ PSp(4,3).

family:finite-unitary#exceptions-3