I'm just starting to learn Quantum Mechanics, and this question is confusing me:
we say that the probability of finding a particle in a state given by the Eigenstate $o\_i$ is the modulus squared of the eigenvalue of the eigenstate, call it $|c\_n|^2$. What is the difference in $|c\_n|^2$ and the probability density $\rho$? What is the physical interpretation of $\rho$?