Why is a unified field theory necessary?
69318
Why do we need a Theory-Of-Everything (TOE)?
143668
Theoretical reasons for charge quantization
125081
What is the reasoning that leads one to postulate this second form for the relativistic particle action?
155043
Substitution $\partial_\mu \to D_\mu \equiv \partial_\mu + ieA_\mu$ allows the introduction of electromagnetic interactions
43046
Do Maxwell's Equations overdetermine the electric and magnetic fields?
128937
Lie theory and particle physics
130752
Can we treat $\psi^{c}$ as a field independent from $\psi$?
983
Use partial or covariant derivatives when deriving equations of a field theory?
130259
Is the S-Matrix the only quantum field observable?
33669
In what sense is a scalar field observable in QFT?
150283
Prerequisites and introduction to string theory
134571
Why should a (physical) principle be applicable to different systems in different positions in space and time?
36490
Why is Newton's first law necessary?
13580
Motivation to understand double dual space
75612
Why are differential equations for fields in physics of order two?
81986
What is more fundamental, fields or particles?
123497
Quantum Field Theory without LSZ, how is it possible?