Tensor product of Clifford algebra with another (non-Clifford)
For a given quadratic form $Q$, I'd wish to symbolically manipulate expressions in Cl${}_Q \otimes \mathbb C\langle x_1,\ldots, x_n \rangle $ (if my notation is unclear, the latter factor is the free algebra; in reality, this algebra is generated by finite matrices, but this plays no role in the manipulations I wish to obtain below).
As background: If I take the product of Cl${}_Q \otimes $ Cl${}_Q $, no problem:
Q=DiagonalQuadraticForm(ZZ,[1,2,3,4])
Cl = CliffordAlgebra(Q)
Cl.<e1,e2,e3,e4> = CliffordAlgebra(Q)
e1*e2 - e2*e1 == 2*e1*e2 # True
e4**2 == 4 # True.
( e1.tensor(e2) + e2.tensor(e1) ) * e2.tensor(e1) ==
-2*Cl(1). tensor(Cl(1)) + (e1*e2).tensor( e1*e2) # True
If I take the product $ \mathbb C\langle x_1,\ldots, x_n \rangle \otimes \mathbb C\langle x_1,\ldots, x_n \rangle $, no problem either:
F=FreeAlgebra(SR,2,'x') # here n=2
Fsq = F.tensor(F)
x0,x1=F.gens()
x0.tensor(x1) in Fsq #True
Naively I tried to define Cl${}_Q \otimes \mathbb C\langle x_1,\ldots, x_n \rangle $ via Cl.tensor(F)
which yields error
'Rings_with_category' object has no attribute 'TensorProducts'
Is there a way to implement Cl${}_Q \otimes \mathbb C\langle x_1,\ldots, x_n \rangle $ in Sagemath, without the necessity to create a class to deal with linearity, cancellations, etc, and rather inherit those properties as implemented in each of the factors?
EDIT: I should say that forming a triple product sometimes works, sometimes it doesn't (by running the same code) KeyError: (((Category of finite dimensional super algebras with basis over fields, Category of algebras with basis over Symbolic Ring),), ()) (too long to be displayed, then again... ) AttributeError: 'Rings_with_category' object has no attribute 'TensorProducts' even though the tree factors have the same base ring.
You need the same base ring:
works.
Many thanks. I should say that forming a triple product sometimes work, sometimes it doesn't (by running the same code)
KeyError: (((Category of finite dimensional super algebras with basis over fields, Category of algebras with basis over Symbolic Ring),), ())
(too long to be displayed, then again... )AttributeError: 'Rings_with_category' object has no attribute 'TensorProducts'
even though the tree factors have the same base ring.This could be related to the auld bug : https://github.com/sagemath/sage/issu...
Thanks for the link