Remove PU1 and PU1Irrep

This might need some more theoretical foundation, which we can add at a later point

src/TensorKit.jl

@@ -12,7 +12,7 @@ export Sector, AbstractIrrep, Irrep
 export FusionStyle, UniqueFusion, MultipleFusion, MultiplicityFreeFusion,
        SimpleFusion, GenericFusion
 export BraidingStyle, SymmetricBraiding, Bosonic, Fermionic, Anyonic, NoBraiding
-export Trivial, Z2Irrep, Z3Irrep, Z4Irrep, ZNIrrep, U1Irrep, SU2Irrep, CU1Irrep, PU1Irrep
+export Trivial, Z2Irrep, Z3Irrep, Z4Irrep, ZNIrrep, U1Irrep, SU2Irrep, CU1Irrep
 export FermionParity, FermionNumber, FermionSpin
 export FibonacciAnyon, IsingAnyon
 
@@ -38,14 +38,14 @@ export infimum, supremum, isisomorphic, ismonomorphic, isepimorphic
 export sectortype, sectors, hassector, Nsymbol, Fsymbol, Rsymbol, Bsymbol,
        frobeniusschur, twist
 export fusiontrees, braid, permute, transpose
-export ZNSpace, SU2Irrep, U1Irrep, CU1Irrep, PU1Irrep
+export ZNSpace, SU2Irrep, U1Irrep, CU1Irrep
 # other fusion tree manipulations, should not be exported:
 # export insertat, split, merge, repartition, artin_braid,
 #        bendleft, bendright, foldleft, foldright, cycleclockwise, cycleanticlockwise
 
 # some unicode
 export ⊕, ⊗, ×, ⊠, ℂ, ℝ, ℤ, ←, →, ≾, ≿, ≅, ≺, ≻
-export ℤ₂, ℤ₃, ℤ₄, U₁, SU, SU₂, CU₁, PU₁
+export ℤ₂, ℤ₃, ℤ₄, U₁, SU, SU₂, CU₁
 export fℤ₂, fU₁, fSU₂
 export ℤ₂Space, ℤ₃Space, ℤ₄Space, U₁Space, CU₁Space, SU₂Space
 

src/sectors/groups.jl

@@ -5,7 +5,6 @@ abstract type AbelianGroup <: Group end
 
 abstract type ℤ{N} <: AbelianGroup end
 abstract type U₁ <: AbelianGroup end
-abstract type PU₁ <: AbelianGroup end
 abstract type SU{N} <: Group end
 abstract type CU₁ <: Group end
 

src/sectors/irreps.jl

@@ -115,8 +115,6 @@ an integer for a linear representation. However, it is often useful to allow hal
 to represent irreps of ``U₁`` subgroups of ``SU₂``, such as the Sz of spin-1/2 system.
 Hence, the charge is stored as a `HalfInt` from the package HalfIntegers.jl, but can be
 entered as arbitrary `Real`. The sequence of the charges is: 0, 1/2, -1/2, 1, -1, ...
-
-See also: [`PU1Irrep`](@ref)
 """
 struct U1Irrep <: AbstractIrrep{U₁}
     charge::HalfInt
@@ -145,47 +143,6 @@ Base.hash(c::U1Irrep, h::UInt) = hash(c.charge, h)
     return isless(abs(c1.charge), abs(c2.charge)) || zero(HalfInt) < c1.charge == -c2.charge
 end
 
-"""
-    PU1Irrep(j::Rational)
-    Irrep[PU₁](j::Rational)
-
-Represents irreps of the group ``PU₁``, corresponding to projective representations of the
-group ``U₁``. The irrep is labelled by a charge, which should be a rational number, but can
-be entered as arbitrary `Real`. The sequence of the charges is ordered by the absolute
-value, with positive entries first. Note that if only half-integer charges are required, it
-is better to use [`U1Irrep`](@ref) instead.
-
-See also: [`U1Irrep`](@ref)
-"""
-struct PU1Irrep <: AbstractIrrep{PU₁}
-    charge::Rational{Int}
-end
-Base.getindex(::IrrepTable, ::Type{PU₁}) = PU1Irrep
-Base.convert(::Type{PU1Irrep}, c::Real) = PU1Irrep(c)
-
-Base.one(::Type{PU1Irrep}) = PU1Irrep(0)
-Base.conj(c::PU1Irrep) = PU1Irrep(-c.charge)
-⊗(c1::PU1Irrep, c2::PU1Irrep) = (PU1Irrep(c1.charge + c2.charge),)
-
-Base.IteratorSize(::Type{SectorValues{PU1Irrep}}) = IsInfinite()
-
-# not sure how to define the iteration order here
-# function Base.iterate(iter::SectorValues{PU1Irrep}, (p, q)::Tuple{Int,Int}=(0, 1))
-#     q == 0 && return iterate(iter, (1, p))
-#     # skip rationals that can be simplified
-#     gcd(p, q) > 1 && return iterate(iter, (p + 1, q - 1))
-#     return PU1Irrep(p // q), p > 0 ? (-p, q) : (-p + 1, q - 1)
-# end
-function Base.iterate(::SectorValues{PU1Irrep}, i=0 // 1)
-    return i <= 0 ? (PU1Irrep(i), 1 - i) : (PU1Irrep(i), -i)
-end
-
-Base.hash(c::PU1Irrep, h::UInt) = hash(c.charge, h)
-@inline function Base.isless(c1::PU1Irrep, c2::PU1Irrep)
-    return isless(abs(c1.charge), abs(c2.charge)) ||
-           zero(typeof(c1.charge)) < c1.charge == -c2.charge
-end
-
 # Non-abelian groups
 #------------------------------------------------------------------------------#
 # SU2Irrep: irreps of SU2 are labelled by half integers j

src/spaces/gradedspace.jl

@@ -268,7 +268,6 @@ const Z3Space = ZNSpace{3}
 const Z4Space = ZNSpace{4}
 const U1Space = Rep[U₁]
 const CU1Space = Rep[CU₁]
-const PU1Space = Rep[PU₁]
 const SU2Space = Rep[SU₂]
 
 # Unicode alternatives
@@ -277,5 +276,4 @@ const ℤ₃Space = Z3Space
 const ℤ₄Space = Z4Space
 const U₁Space = U1Space
 const CU₁Space = CU1Space
-const PU₁Space = PU1Space
 const SU₂Space = SU2Space

test/runtests.jl

@@ -49,7 +49,7 @@ function hasfusiontensor(I::Type{<:Sector})
     end
 end
 
-sectorlist = (Z2Irrep, Z3Irrep, Z4Irrep, U1Irrep, PU1Irrep, CU1Irrep, SU2Irrep, NewSU2Irrep,
+sectorlist = (Z2Irrep, Z3Irrep, Z4Irrep, U1Irrep, CU1Irrep, SU2Irrep, NewSU2Irrep,
               FibonacciAnyon, IsingAnyon, FermionParity, FermionParity ⊠ FermionParity,
               Z3Irrep ⊠ Z4Irrep, FermionParity ⊠ U1Irrep ⊠ SU2Irrep,
               FermionParity ⊠ SU2Irrep ⊠ SU2Irrep, NewSU2Irrep ⊠ NewSU2Irrep,