centreLie -- computes the central elements

Synopsis

• Usage:

  c=centreLie(d)

  cAll=centreLie(L)

• Inputs:

  • d, an integer, the degree
  • L, an object of class LieAlgebra
• Outputs:

  • c, a list, the central elements of degree d
  • cAll, a list, the central elements of degree less than or equal to L.compdeg - (maximal degree of generators)

Description

i1 : L = lieAlgebra({a,b,c},{[a,b],[a,c], [c,b,c],[b,b,c,b]})

o1 = L

o1 : LieAlgebra

i2 : centreLie 1

o2 = {[a]}

o2 : List

i3 : centreLie 2

o3 = {}

o3 : List

i4 : centreLie L

o4 = {[a]}

o4 : List

i5 : L.compdeg

o5 = 3

i6 : computeLie 4

o6 = {3, 1, 1, 0}

o6 : List

i7 : centreLie L

o7 = {[a], [b, c, b]}

o7 : List

See also

• annLie -- computes a basis for the annihilator in a given degree
• divisorLie -- computes a basis for the divisor subspace