Prove the operator d/dx is hermitian

  • Thread starter Thread starter baldywaldy
  • Start date Start date
  • Tags Tags
    Hermitian Operator
Click For Summary

Homework Help Overview

The discussion revolves around the properties of the operator d/dx in the context of quantum mechanics, specifically whether it is hermitian. The original poster seeks to prove that this operator is not hermitian, referencing the necessary condition involving inner products.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to apply integration by parts to evaluate the hermitian condition but expresses confusion about the process due to the presence of two functions and the operator.

Discussion Status

Some participants have offered guidance by suggesting the use of integration by parts. However, there is a lack of explicit consensus on how to proceed with the application of this method in the given context.

Contextual Notes

The original poster notes a struggle with using LaTeX for mathematical expressions, which may impact the clarity of their attempts and reasoning.

baldywaldy
Messages
19
Reaction score
0
Hiya :) the title is meant to be prove it isn't hermitian

Homework Statement


Prove the operator d/dx is hermitian


Homework Equations


I know that an operator is hermitian if it satisfies the equation : <m|Ω|n> = <n|Ω|m>*


The Attempt at a Solution


Forgive the lack of latex , I have know idea how to use it and find it baffling.

the intergral of (fm* d/dx fn) dx = the intergral of fm* d fn
={fm* fn - the intergral of fn d fm*} between the limits x=infinity and - infinity.

This is where i get stuck. I just don't know where to go from here, like i said sorry for the lack of latex usage :(.

Thanks for the help :D
 
Physics news on Phys.org
Think of integration by parts.

ehild
 
I know intergration by parts but i just don't understand how to apply in this situation because there are two functions and an operator
 
d/dx f means that you differentiate f with respect to x. d/dx f = df/dx = f'

You have to show that \int{f_n f&#039;_mdx}\neq (\int{f&#039;_n f_mdx})^*

ehild
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
5K
  • · Replies 10 ·
Replies
10
Views
15K
  • · Replies 17 ·
Replies
17
Views
2K
  • · Replies 4 ·
Replies
4
Views
7K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
Replies
4
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K