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Oct
24
reviewed Close Closed solutions for `FindRoot`, no solutions for `Reduce` or `Solve`
Oct
23
revised Pull out scalars from NonCommutativeMultiply in commutator of SU2 spin algebra
physics tag added
Oct
23
comment Pull out scalars from NonCommutativeMultiply in commutator of SU2 spin algebra
@DanielLichtblau Just for completeness: There's also this related question where your linked FAQ is equally relevant (of course it's relevant for lots of other questions...)
Oct
23
revised Pull out scalars from NonCommutativeMultiply in commutator of SU2 spin algebra
Added reverse steps from matrices back to symbols
Oct
23
awarded  Nice Answer
Oct
22
revised Pull out scalars from NonCommutativeMultiply in commutator of SU2 spin algebra
Different definition with the same properties used. Gives different result.
Oct
22
revised Pull out scalars from NonCommutativeMultiply in commutator of SU2 spin algebra
Motivation
Oct
22
revised Pull out scalars from NonCommutativeMultiply in commutator of SU2 spin algebra
copied wrong defininitions
Oct
22
revised Pull out scalars from NonCommutativeMultiply in commutator of SU2 spin algebra
Error copying equation
Oct
22
answered Pull out scalars from NonCommutativeMultiply in commutator of SU2 spin algebra
Oct
22
comment Pull out scalars from NonCommutativeMultiply in commutator of SU2 spin algebra
I would do this without NonCommutativeMultiply altogether. But if you do want to go that route, I think you will have to provide the code that you tried for your commutator algebra. Otherwise we'd have to re-invent the wheel before answering.
Oct
21
revised Why doesn't FullSimplify simplify expressions with DiracDelta?
small clarification
Oct
21
revised Why doesn't FullSimplify simplify expressions with DiracDelta?
Added more explanation
Oct
21
comment Why doesn't FullSimplify simplify expressions with DiracDelta?
@NikkiBisschop I edited my answer to include more examples, and what I say in the first paragraph of the edit is based on your comment. It is in fact the answer to your overarching question why DiracDelta isn't simplified as such. One needs the information identifying the integration variable to make the correct simplification.
Oct
21
comment Why doesn't FullSimplify simplify expressions with DiracDelta?
@Dr.WolfgangHintze I just checked in version 8.0.4, and I cannot reproduce your problem. It simplifies correctly on my system, even in the older version. This is on Mac OS 10.7.5.
Oct
21
comment Why doesn't FullSimplify simplify expressions with DiracDelta?
@Dr.WolfgangHintze Ah, so this time it was good that I used version 10.0.1. There, it does simplify exactly to what you quoted...thanks for pointing out the issue with 8!
Oct
21
comment Why doesn't FullSimplify simplify expressions with DiracDelta?
@Dr.WolfgangHintze I did find a shortcoming when I switched the variables in your example and replaced the square by a symbolic n - see my edit. But I think one gets pretty decent results all in all.
Oct
21
revised Why doesn't FullSimplify simplify expressions with DiracDelta?
Added more examples and a caveat
Oct
21
revised Why doesn't FullSimplify simplify expressions with DiracDelta?
Added more examples
Oct
21
comment Why doesn't FullSimplify simplify expressions with DiracDelta?
@Dr.WolfgangHintze Well, you get the correct answer. There is no problem at all. @Nikki Yes, the notation of the Dirac delta function is sometimes ambiguous because it doesn't include the info as to which variable is the integration variable. This can only be fixed by stating that information in the (Inverse)FourierTransform.