- #1
fog37
- 1,568
- 108
Hello Everyone. I am searching for some clarity on this points. Thanks for your help:
Based on Schrodinger wave mechanics formulation of quantum mechanics, the states of a system are represented by wavefunctions (normalizable or not) and operators (the observables) by instructions i.e. operations build from ##x,y,z## and the partial derivates like ##\frac{\partial}{\partial x}## etc. All (or almost) all operators can be built from the position operator and the linear momentum operator. All this is true regardless of the vector space being finite or infinite dimensional, discrete or continuous, correct?
According to Dirac (bra and ket) formulation instead, the system's state are viewed as vectors which can be described as row or column vectors, containing components, and the operators are matrices, with indexed elements, only if the vector space is finite/infinite dimensional and discrete. What if the vector space was finite/infinite dimensional and continuous? How would operators be represented in a continuous vector space? The matrix representation would not be possible. The vector would just be described as ##|\Psi>## using the ket notation but could not have a row or column representation, correct?
thanks,
fog37
Based on Schrodinger wave mechanics formulation of quantum mechanics, the states of a system are represented by wavefunctions (normalizable or not) and operators (the observables) by instructions i.e. operations build from ##x,y,z## and the partial derivates like ##\frac{\partial}{\partial x}## etc. All (or almost) all operators can be built from the position operator and the linear momentum operator. All this is true regardless of the vector space being finite or infinite dimensional, discrete or continuous, correct?
According to Dirac (bra and ket) formulation instead, the system's state are viewed as vectors which can be described as row or column vectors, containing components, and the operators are matrices, with indexed elements, only if the vector space is finite/infinite dimensional and discrete. What if the vector space was finite/infinite dimensional and continuous? How would operators be represented in a continuous vector space? The matrix representation would not be possible. The vector would just be described as ##|\Psi>## using the ket notation but could not have a row or column representation, correct?
thanks,
fog37