New posts in Hilbert Space

Different Hilbert spaces in quantum mechanics

Common eigenfunctions of commuting operators: case of degeneracy

Meaning of degeneracy in Quantum Mechanics

Physically unacceptable solutions for the QM angular equation

Confusion about quantum field in AQFT

A rigorous definition of the exponential of an operator in QM?

Is there a classical analogue to purification of quantum states?

Can I define a unitary representation of the Lorentz group on the Hilbert space of a theory which breaks Lorentz invariance?

What does it mean for an operator to have both a continuous and discrete spectrum?

Space of density matrix