- action is extremized or at a saddle point, not necessarily minimized
- Action is not quantized in QM (and quantum-mechanical action is not quite the same as classical action). There's another very indirectly related notion of "action" which shows up in historical semiclassical approximations and which is quantized. The author has likely confused the two.
- SU(2) is not the gauge group of the weak interaction, because there is no such thing. A purely weak gauge theory with no EM is not possible, on account of having massive force carriers. The SU(2) and SU(1) in SU(3) x SU(2) x U(1) corresponds to weak isospin and weak hypercharge respectively, not weak charge and (EM) charge.
But even if all the errors were corrected there's a huge amount of missing context. (For instance, the actual content of the standard model Lagrangian - the fact that there are 19 free parameters is in no way sufficient to determine it) And even if you had all of that, a full reduction of macrophysics to microphysics is likely computationally intractable, even in principle.
- action is extremized or at a saddle point, not necessarily minimized
- Action is not quantized in QM (and quantum-mechanical action is not quite the same as classical action). There's another very indirectly related notion of "action" which shows up in historical semiclassical approximations and which is quantized. The author has likely confused the two.
- SU(2) is not the gauge group of the weak interaction, because there is no such thing. A purely weak gauge theory with no EM is not possible, on account of having massive force carriers. The SU(2) and SU(1) in SU(3) x SU(2) x U(1) corresponds to weak isospin and weak hypercharge respectively, not weak charge and (EM) charge.
But even if all the errors were corrected there's a huge amount of missing context. (For instance, the actual content of the standard model Lagrangian - the fact that there are 19 free parameters is in no way sufficient to determine it) And even if you had all of that, a full reduction of macrophysics to microphysics is likely computationally intractable, even in principle.