Probability and Current Densities:
The probability density for an infinitesimal region is equal to the square modulus of the wave function, as proposed by the physicist Max Born.
eq.1One can utilize a form of Gauss' divergence theorm to obtain more information concerning this, which is:
eq.2Rewriting the time derivative fo the probability density function:
eq.3Expanding:
eq.4The time-dependent Schrödinger Equation for the free particle is of the form:
eq.5Rewriting:
eq.6Applying these two equations in eq.4:
eq.7Collecting:
eq.8Canceling the negative sign and the operator-vector del:
eq.9