General commutation relations for quantum operators

In summary, The question asks if a commutation relation derived using a particular representation is valid for any representation. The answer is that it depends on how the relation is expressed, as long as it is done so without using representation-specific items. If this is the case, then the relation will be representation-independent and can be proven using representation-specific working.
  • #1
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(This is not a homework problem). I'm an undergrad physics student taking my second course in quantum. My question is about operator methods. Most of the proofs for different commutation relations for qm operators involve referring to specific forms of the operators given some basis. For example, to derive [x,p] = i hbar , you can use the representation of x and p in coordinate basis (multiplication by x and differential operator with respect to x) and consider the action of the commutator on some function of x. However, some of the material I've been reading seems to imply that we can understand the properties of operators without making explicit reference to a particular representation of an operator in some basis. My question is this: If you derive a commutation relation for 2 operators using a particular representation, is it valid for any representation? If so, is it generally easier to figure out a commutation relation by picking a representation or are there easier and possibly more general methods? Thank you
 
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  • #2
cdot said:
My question is this: If you derive a commutation relation for 2 operators using a particular representation, is it valid for any representation?
It depends on how the relation is expressed. In general, if it is expressed without using any representation-specific items, then it will be representation-independent. That is, you can use representation-specific working to prove a non-representation-specific result, as long as the result is expressed in non-representation-specific symbols.
 

1. What are commutation relations in quantum mechanics?

Commutation relations in quantum mechanics describe the relationship between two operators and how they behave under mathematical operations. They are used to determine the order in which operators are applied in a given equation.

2. What is the significance of commutation relations in quantum mechanics?

Commutation relations are crucial in quantum mechanics as they help determine the uncertainty principle, which states that certain pairs of physical quantities cannot be simultaneously measured with arbitrary precision.

3. How are commutation relations represented in mathematical notation?

Commutation relations are typically represented using the commutator bracket notation, [A, B] = AB - BA, where A and B are operators. This signifies the commutator of A and B, which is a measure of how much the order of the operators affects the outcome of the equation.

4. Can commutation relations be used to solve equations in quantum mechanics?

Yes, commutation relations can be used to simplify and solve equations in quantum mechanics. By rearranging the order of operators according to their commutation relations, the equations can be simplified and solved more easily.

5. Are commutation relations the same for all quantum operators?

No, commutation relations differ for different operators and can only be applied to operators that operate on the same system. For example, the commutation relations for position and momentum operators are different from those for energy and spin operators.

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