- #101

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If the particles are independent, you can write them as a tensorproduct of two vectors, if they are correlated then you can't nessecarily.

The reason i said you equation was wrong, was because we where talking about QM, so it didn't make sense.

Again you are right that a vector is often described by a n-tuple, but as i have said a lot of times in this thread, the tuple doesn't make sense with out a basis, telling us what it means. A bit like your equation didn't make sense because you didn't tell what you ment by |p> and |F>.

The problem about adjoint, is to write the definition used in math

[tex] <x,A y> = <A^*x,y> [/tex]

in diracs notation. You have to be very carefull to write this.

Not sure what your point is about fock-space? Is it because if we have a space describing one particle, and we take a tensor product between such two states then we are not in the space anymore, but in the fock space formalism you incorporate this problem?

I haven't read diracs book, but it sounds interesting, I will look at it in my vecation, thanks for the reference. I agree that he made the notation because it made it simpler to write (maybe to remember some rules of manipulating), but I just think that people often get a bit confused about it, because one learn QM with wavefunctions first and then learn bra-ket, then often people think that the wavefunction is used just like a ket, and it often isn't (even though you proberly could, after all L^2 is a vector space).