One of this quantity's operators is a 3x3 matrix with a 1 in the top left, a -1 in the bottom right, and 0s everywhere else.
One of this quantity's operators is a 3x3 matrix with a 1 in the top left, a -1 in the bottom right, and 0s everywhere else. The operators corresponding to the three Cartesian vector components of this quantity do not commute with each other, but they all commute with the operator corresponding to this quantity squared. The eigenfunctions of this quantity's operators are the spherical harmonics. The conservation of this quantity causes the radius vector for the (*) orbit of a planet to sweep out equal areas in equal time, a fact known as Kepler's 2nd Law. This quantity is equal to the product of moment of inertia with angular velocity, and it is conserved in the absence of an external torque. For 10 points, name this quantity symbolized L which is defined as the cross product of position with linear momentum.
One of this quantity's operators is a 3x3 matrix with a 1 in the top left, a -1 in the bottom right, and 0s everywhere else.
angular momentum [or rotational momentum, DO NOT accept or prompt "linear momentum" or just "momentum"]