# How much physics a mathematician needs to know to study GR? [duplicate]

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I'm intending to study General Relativity on my own. The thing is, my physics background is not very strong. I know classical mechanics and I know some electromagnetism. I'm familiar with Gauss' law, Ampere's law, RLC circuits, ... but I still have problems with the intuition behind concepts like 'momentum'. I know that momentum is nothing but $p=mv$ and I know that the change in momentum is associated to a force acting on the particle by the equation $F=\displaystyle {\mbox d p \over \mbox d t}$ but I'm not sure if my background is enough.

I know some differential geometry and this semester I'm going to take a course in topological manifolds. I guess my mathematical background is strong enough for GR. But I don't know where I should start. I know the basics of special relativity, but I only know the basics, I don't know every details that a physics student must know. So, where do you think I should start from?

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## marked as duplicate by Qmechanic♦Aug 7 '13 at 15:53

As you're a mathematician, I'll just discuss the Physics prerequwisites .

1. Newtonian Mechanics. You seem to know this .
2. Lagrangian Mechanics . Unarguably the most elegant formulation of all of Classical Mechanics .
3. Hamiltonian Mechanics . An uglier, but equally useful (almost), formulation .
4. Newtonian Gravity . The theory of gravity as an inverse square field with the "charge" as the mass .
5. Maxwellian Electromagnetism . A Lorentz invariant formulation of EM. Formulated way before Lorentz Invariance and Lorentz Symmetry were ever thought of.
6. Special Relativity (the Minkowskian formulation, of course, is needed here .) . Of course .

As you're a mathematician, you'd probably like Wald, R.M's General Relativity, a mathematically rigorous textbook . Though I don't like it as it is too rigorous . I prefer Ludvigsen's General Relativity: A geometric approach. But that isn't a book a mathematician would like .

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Sounds like I will have to spend a long time studying all those, right? I know Newtonian gravity to some extents. I have also completed a course on Astronomy 101 on coursera.org from Duke university. Do you think that's enough background for 4.? Would you please suggest some easy books for these subjects? –  some1.new4u Aug 7 '13 at 15:43
@some1.new4u: For Newtonian Mechanics & Maxwellian Electromagnetism & Special Relativity (in Einstein's approach), you can read Jewett and Serway Physics for Scientists and Engineers (With Modern Physics). It doesn't cover Lagrangian Mech, Hamiltonian Mech, or GR, though . –  Dimensio1n0 Aug 7 '13 at 15:46
@some1.new4u: For Special Relativity in Minkowski 's approach, Ludvigsen covers it, I think Wald does too, can't remember . Lagrangian Mech and Hamiltonian Mech: Wikipedia is enough . –  Dimensio1n0 Aug 7 '13 at 15:47