On Sunday, May 22, 2011 10:44:50 PM UTC-7, Simon King wrote: > > Hi Rajeev, > > On 22 Mai, 20:25, Rajeev <[email protected]> wrote: > > I wish to simplify some calculation that appear in quantum mechanics. To > > begin we use non-commutative variables as - > > > > sage: R.<a,b> = FreeAlgebra(QQ, 2) > > sage: (a+b)^3 + a*(a+b) > > a^2 + a*b + a^3 + a^2*b + a*b*a + a*b^2 + b*a^2 + b*a*b + b^2*a + b^3 > > > > I want to impose the commutation relation [a,b]=1 and bring the > expression > > to normal form (i.e. in all terms b appears before a, e.g. a*b gets > replaced > > by b*a + 1). Is it possible to do this? > > Well, if you start with a free algebra generated by a and b, and you > mod out the commutator of a and b, then you obtain the polynomial ring > generated by a and b, up to isomorphism.
The poster wants to impose the relation [a,b]=1, not [a,b]=0. -- John -- To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
