Recent content by Bapelsin

Homework Statement I'm trying to follow the solution to a homework problem in QM, and I don't fully understand this step. Where does the factor (2\pi)^3 come from? \int...

Homework Statement Two electrical dipoles with dipole moments \vec{p}_0=p_0\hat{y} and \vec{p}_1=p_1\hat{y} are located in the xy-plane. \vec{p}_0 i located at the origin and \vec{p}_1 is initially in (x,y)=(a,0). What work is required to move \vec{p}_1 (with unhanged directon) to the point...

Thank you! That was really helpful.

Electrostatics: spherical shell [SOLVED] Homework Statement A point charge Q_1 is located in the centre of a spherical conducting shell with inner radius a and outer radius b. The shell has total charge Q_2. Determine the electrostatic field \vec{E} and the potential \phi everywhere in...

Homework Statement The time-evolution operator \hat{U}(t,t_0) for a time-dependent Hamiltonian can be expressed using a Magnus expansion, which can be written...

Yes. Thank you!

Show that wave packet is an eigenstate to operator [SOLVED] Homework Statement For a harmonic oscillator we can define the step up and down operators \hat{a} and \hat{a}^{\dagger} and their action as \hat{a}=\sqrt{\frac{m\omega}{2\hbar}}(\hat{x}+\frac{\imath}{m\omega}\hat{p}) \quad...

Thanks for you help! I got it right this time! :smile:

Homework Statement The acitvities from the fission products 131I and 133I were measured in the air of Gothenburg April 28 1986 at 17:00. The result was 0.12 Bq/m3 and 0.39 Bq/m3 for 131I and 133I respectively. These isotopes came from the Chernobyl nuclear reactor disaster. Use this...

I forgot to mention that my main problem is that I don't know how a Lorentz' transformation in generalized coordinates look like. I've only dealt with such in Cartesian coordinates (Google etc. doesn't help me out much at all with this).

Gigi: Thanks for your tip, but I don't think I can obtain that book soon enough. But maybe later. :-) samalkhaiat: Thank you! First of all I want to tell you that I am more or less a layman when it comes to this (I haven't studied natural sciences for almost three years, and I'm I only...

Hello, I need help showing that the Euler-Lagrange equations are Lorentz invariant (if Einstein's extended energy concept is used). Is there an easy way to show this? Any help would be very much appreciated.