- #1

bon

- 559

- 0

## Homework Statement

Suppose we have a system and that {|a>, |b>, ...} is a complete and orthonormal basis for the system

Am i right in thinking Ʃ(j) <k|j><j|i> = <k|i> = 0 unless k=i?

In other words, does the LHS expression equal the middle one because Ʃ(j) |j><j| is just the insertion of the identity and we can put it in anywhere?

## Homework Equations

## The Attempt at a Solution

I've explained my attempt above.

Thanks!