Lagrangian for E and B fields, not vector potential?

AI Thread Summary
The discussion centers on finding a Lagrangian expressed in terms of the electric field (E) and magnetic field (B) that can derive Maxwell's equations. One participant mentions a specific Lagrangian, L=-1/4 FμνFμν, which yields the second-order Maxwell equations but questions the equivalence to the first-order form. There is uncertainty about whether the second-order equations can fully represent the first-order equations commonly used in electromagnetism. Additionally, it is noted that the field tensor F is typically defined in relation to the vector potential rather than directly in terms of E and B. The conversation highlights the complexity of formulating a Lagrangian that meets these criteria.
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Anyone know of a Lagrangian given in terms of E and B (or equivalently the tensor F) that yields Maxwell equations? A link or reference would be appreciated.

I can write down such a Lagrangian which yields the two second-order Maxwell equations, but not the usual four 1st order equations. And I'm not sure: are the second order equations equivalent to the first order form?
 
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L=-\frac{1}{4}F_{\mu\nu}F^{\mu\nu}

But then F is defined in terms of (the derivatives of) the potential, not E and B.
 
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