# Is Dirac Notation Standard in QM?

1. Jan 3, 2005

### houserichichi

Hi all, I recently purchased Shankar's Principles of Quantum Mechanics which relies heavily on Dirac's bra-ket notation. I'm just wondering if this is the norm or should I get used to switching between what I'm learning and some other accepted standard notation? Thanks in advance!

2. Jan 3, 2005

### dextercioby

I've heard similar "complaints" about Sakurai's "Modern Quantum Mechanics".
The short,very short story is:
DIRAC NOTATION IS NOT ONLY TRADITIONAL,ELEGANT,USEFUL,HANDY,BUT IT'S FUNDAMENTAL.The Hungarian mathematician John von Neumann (the one who founded QM mathematically) gave a rigurous mathematical founding of Dirac's "trick" of denoting linear functionals of Hilbert spaces by "bra" vectors and vectors from Hilbert spaces by "ket".

So the message is:i cannot conceive QM without Dirac's notation.Why would u??

Daniel.