Is another definition of sum useful?

In summary, Von Neumann and Bell pointed out that the fact that the spectrum of A+B does not equal the sum of the spectra of A and B can lead to contradictions. However, by replacing the sum with A⊗1+1⊗B, the inequality becomes an equality and makes things easier. This also leads to integer eigenvalues for CHSH. The idea that one can redefine a problem to avoid contradictions, but this may lead to other issues. The discussion revolves around the relationship between measurement results and eigenvalues, and the potential discrepancy between the two.
  • #1
jk22
729
24
Von neumann and bell pointed out that basically the non isomorphic fact that the spectrum $$\sigma(A+B)!=\sigma(A)+\sigma(B)$$ leads to contradictions.

If we but replace the sum by $$A\otimes 1+1\otimes B$$ then the above inequality becomes an equality.
This would make things much easier.

We would get as eigenvalues for chsh integer values for example.
 
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  • #2
Note: The inequality sign is \neq to give ##\neq##.

It is always possible to define a problem away - but adopting the definition in general leads to other problems in other places.
In this case, the observation is about something of Nature. You don't get to make Nature something else by changing the definitions of the words used to describe Her.
 
  • #3
But in our case with the usual sum of operators Bell's theorem could be rephrased as $$1+1+1-1=2\sqrt{2}$$ ? (if we compute the values that are afterwards averaged)

Where we need to find the operation + between measurement results.
 
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  • #4
My last post is confusing, in fact what I mean is that There seem to be a discrepancy between measurement results (0,2,4) and eigenvalues (0,2sqrt 2) ?
 

FAQ: Is another definition of sum useful?

1. What is the definition of sum?

The definition of sum is the result of adding two or more numbers together.

2. How is sum used in mathematics?

Sum is a basic mathematical operation that is used to find the total value when numbers are combined.

3. Why is another definition of sum needed?

Another definition of sum may be useful in certain contexts or fields, such as statistics or computer programming, where the traditional definition may not apply.

4. Can you give an example of another definition of sum?

An example of another definition of sum is the "concatenation" of strings in computer programming, where two or more strings are combined to create a new string.

5. How does having multiple definitions of sum impact its use?

Having multiple definitions of sum can make it more versatile and applicable in various situations, but it can also lead to confusion if the context is not specified.

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