Documentation

Functions

GroupFunctions.group_functionFunction
group_function(λ::Irrep, tu::YoungTableau, tv::YoungTableau)

Returns the symbolic group function corresponding to irrep λ and Young tableaux tu and tv.

Example:

julia> t = YoungTableau([2,1]); fill!(t, [1,2,3]);
julia> group_function([2,1,0], t, t)
group_function(λ::Irrep, tab_u::YTableau, tab_v::YTableau; verbose::Bool = false) -> Basic

Compute group theoretical function based on Young tableaux and irreducible representations.

Arguments:

  • λ::Irrep: Irreducible representation
  • tab_u::YTableau: First Young tableau
  • tab_v::YTableau: Second Young tableau
  • verbose::Bool: Flag for detailed output (default: false)

Returns:

  • Complex: Group function evaluated

Notes:

  • Uses SymEngine for symbolic computation
  • Involves matrix operations and coset calculations
source
group_function(λ::Irrep, tu::GTPattern, tv::GTPattern)

Returns the symbolic group function corresponding to irrep λ and GT patterns tu and tv.

Example:

julia> t = GTPattern([[2,1,0],[2,1],[2]],[2]);
julia> group_function([2,1,0], t, t)
group_function(λ::Irrep, pat_u::GTPattern, pat_v::GTPattern; verbose::Bool = false) -> Basic

Compute group theoretical function based on Gelfand-Tsetlin patterns and irreducible representations.

Arguments:

  • λ::Irrep: Irreducible representation
  • pat_u::GTPattern: First Gelfand-Tsetlin pattern
  • pat_v::GTPattern: Second Gelfand-Tsetlin pattern
  • verbose::Bool: Flag for detailed output (default: false)

Returns:

  • Basic: Computed polynomial expression in SymEngine format

Notes:

  • Converts GT patterns to Young tableaux for calculations
  • Uses SymEngine for symbolic computation
source
group_function(λ::Irrep, tu::GTPattern, tv::GTPattern, mat::Array{Complex{Float64},2})

Returns the numeric group function, for an SU(n) member mat, corresponding to irrep λ and a pair of GT patterns tu and tv.

julia> using RandomMatrices
julia> mat = rand(Haar(2),3)
julia> t = GTPattern([[2,1,0],[2,1],[2]],[2]);
julia> group_function([2,1,0], t, t, mat)
source
group_function(λ::Irrep, tu::GTPattern, tv::GTPattern, mat::Array{Complex{Float64},2})

Returns the numeric group function, for an SU(n) member mat, corresponding to irrep λ and STYT tu and tv.

Example:

julia> using RandomMatrices
julia> mat = rand(Haar(2),3)
julia> t = YoungTableau([2,1]); fill!(t, [1,2,3]);
julia> group_function([2,1,0], t, t, mat)
source

Gelfand-Tsetlin patterns

GT patterns are used to denote the basis states.

Construction of matrices

GT patterns are used to denote the basis states.

GroupFunctions.bloquesunFunction
bloquesun(size::Int64, position::Int64, angles::Tuple{Float64,Float64,Float64})

Computes the SU(2) matrix using angles an embeds it into a size times size matrix.

Example:

α5,β5 = rand(Float64,2)
yy2=bloquesun(4,2,(α5,β5,α5))
source