centralElements -- Finds central elements in a given degree

Synopsis

Usage:

centralElements(A,n)
Inputs:
- A, an instance of the type NCRing,
- n, an integer, the homogeneous degree in which to compute central elements
Outputs:
- an instance of the type NCMatrix,

If the given NCRing has central elements of the specified degree, this method returns a basis for the space of central elements in that degree.

i1 : B = threeDimSklyanin(QQ,{1,1,-1},{x,y,z})
--Calling Bergman for NCGB calculation.
Complete!

o1 = B

o1 : NCQuotientRing

i2 : centralElements(B,2)

o2 = | x^2 y*x+x*y y^2 |

o2 : NCMatrix

i3 : centralElements(B,3)

o3 = | y^3-y*x*z+x*y*z-x^3 |

o3 : NCMatrix