Commutators for functions of operators (momentum/position)

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SUMMARY

The discussion focuses on the commutation relation between the position operator \(x\) and a function of the momentum operator \(f(p_x)\), specifically demonstrating that \([x, f(p_x)] = i \hbar \frac{d}{d(p_x)} f(p_x)\). Participants referenced the fundamental commutation relation \([x, p_x] = xp - px\) and discussed the application of the chain rule in differentiation. A successful approach involved representing the function as a power series, simplifying the calculation process.

PREREQUISITES
  • Understanding of quantum mechanics, specifically operator algebra
  • Familiarity with the position operator \(x\) and momentum operator \(p_x\)
  • Knowledge of differentiation techniques, including the chain rule
  • Experience with power series representation of functions
NEXT STEPS
  • Study the properties of quantum mechanical operators and their commutation relations
  • Learn about the application of the chain rule in quantum mechanics
  • Explore power series expansions in the context of quantum functions
  • Investigate the implications of the Heisenberg uncertainty principle on position and momentum operators
USEFUL FOR

Students and researchers in quantum mechanics, particularly those studying operator theory and commutation relations in the context of quantum physics.

Ratpigeon
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Homework Statement



show that [x,f(p_x)] = i \hbar d/d(p_x) f(p_x)

Homework Equations



x is the position operator in the x direction, p_x is the momentum operator; i \hbar
d/dx
[x, p_x]=xp-px

The Attempt at a Solution


I'm stuck. maybe chain rule for d/dx and d/d(p_x)...? But I don't see how I'd do it...
 
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Never mind - I had to reqresent it as a power series, and then it was easier
 

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