Quantum Physics - hermitian and linear operators

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SUMMARY

The discussion focuses on proving the Hermitian nature of the operators i(d/dx) and d²/dx² in quantum physics. Participants confirm that the momentum operator '-ih(d/dx)' is Hermitian, and they explore whether multiplying by '-1/h' affects this property. Additionally, they analyze the linearity of operators A and B, defined as Aψ(x)=ψ(x)+x and Bψ(x)=dψ/dx+2ψ/dx(x), respectively, emphasizing the importance of the definition of linearity in their evaluation.

PREREQUISITES
  • Understanding of Hermitian operators in quantum mechanics
  • Familiarity with linear operators and their properties
  • Basic knowledge of differential calculus
  • Concept of wavefunctions and their behavior at infinity
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1. Prove that operators i(d/dx) and d^2/dx^2 are Hermitian.


2. Operators A and B are defined by:

A\psi(x)=\psi(x)+x

B\psi(x)=d\psi/dx+2\psi/dx(x)

Check if they are linear.


The attempt at a solution


I noted the proof of the momentum operator '-ih/dx' being hermitian, should I just multiply all the terms involved in it by '-1/h'? I do not really know what should I do in the second exercise.
 
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-ihbar d/dx is hermitean. You say you have the proof. Now dropping hbar which is a real (as opposed to an imaginary) constant, does it change the hermitean character or not ?

As for the second derivative operator, assuming wavefunctions dropping to 0 when going to infinity, can you show that it's hermitean by maneuvering the integrals ?

Consider the definition of linearity. It's not more complicated than that.
 

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