Recent content by beefbrisket

I am attempting to understand how POVMs fit in with quantum measurement, and I think I am getting tripped up in notation when it comes to multipartite systems. The situation is as follows: System: \rho_A Measurement instrument: \rho_B = |\phi\rangle\langle\phi| (pure state) The multipartite...

My text (Ian Ford - Statistical physics) describes an ideal gas system in a piston being quasistatically compressed by a piston head of area A under external force f. It assumes the system has a uniform pressure p. All good so far. Then it says: "the force pA equals the applied external force f"...

In this video, at around 37:10 he is explaining the orthogonality of spherical harmonics. I don't understand his explanation of the \sin \theta in the integrand when taking the inner product. As I interpret this integral, we are integrating these two spherical harmonics over the surface of a...

In one of Weintraub's intro texts on differential forms he introduces the "fundamental correspondence" between vectors and differential forms in R^3 (haven't been able to find any other sources using this name) and for the correspondence between vectors and 2-forms he indeed uses that ordering...

The question provides the vector field (xy, 2yz, 3zx) and asks me to confirm Stokes' theorem (the vector calc version) but I am trying to use the generalized differential forms version. So, I am trying to integrate \omega = xy\,dx + 2yz\,dy + 3zx\,dz along the following triangular boundary...

In a problem from Hartle's Gravity, we are asked to express the line element in non-Cartesian coordinates u, v which are defined with respect to x, y. I have no problem getting the new expression for the line element, but then we are asked if the new coordinate curves intersect at right angles...