The QCD quark Lagrangian in the chiral limit is $$ L_q = i \bar{q}{\not D} q $$ which possesses a global $SU(3)_L \times SU(3)_R$ symmetry. I've read many places that this is symmetry is spontaneously broken to $SU(3)_V$ by $\langle \bar{q} q \rangle \neq 0$. Question: How does this qualify...

We all know where iron comes from.... but as I am reading up on supernova's it got me wondering why there is as much iron as there is in the universe? Brown dwarf's do not deposit iron... White dwarf's do not deposit iron... Type I supernovas leave no remnant so I can see where there would be...

We know that the speed of light depends on the density of the medium it is travelling through. It travels faster through mediums of less density and vice versa. Now, when we produce sound in a medium, a series of rarefactions and compressions are created in the medium by the vibration of the so...

In Schawrtz, Page 116, formula 8.23, he seems to suggest that the square of the Maxwell tensor can be expanded out as follows: $$-\frac{1}{4}F_{\mu \nu}^{2}=\frac{1}{2}A_{\mu}\square A_{\mu}-\frac{1}{2}A_{\mu}\partial_{\mu}\partial_{\nu}A_{\nu}$$ where: $$F_{\mu\nu}=\partial_{\mu} A_{\nu} - \p...