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 1d revised Mass spectrum of field theory edited tags 1d revised Pauli matrices and $SU(4)$ edited tags; edited title 1d revised Exactly how much lift is needed to overcome the weight of an average person? edited tags 1d comment Derivation of Euler-Lagrange equation from principle of least action Comment to the question (v2): It seems that OP is asking for the standard integration-by-parts argument in calculus of variations that leads to Euler-Lagrange equations. This is shown in many textbooks on the subject (including the above two Wikipedia links $\uparrow$), and e.g. this Phys.SE post and links therein. 1d revised Derivation of Euler-Lagrange equation from principle of least action edited tags 1d comment How to find the rank of the matrix $\frac{\partial ^2\mathcal{L}}{\partial \dot{X^\mu} \partial \dot{X^\nu} }$ for the Nambu-Goto string Lagrangian? Observation: It is tempting to alternatively define $\quad \chi_1 := \frac{1}{2}P^2$, $\quad \chi_0 := P\cdot X^{\prime}$, $\quad \chi_{-1} := \frac{1}{2}(X^{\prime})^2$, and $\quad \chi_{\pm 2} := 0$. Then the PB algebra almost reads $\quad \{\chi_{\alpha}(\sigma),\chi_{\beta}(\sigma^{\prime})\}_{PB} = \left[ \chi_{\alpha+\beta}(\sigma)+\chi_{\alpha+\beta}(\sigma^{\prime})\right] \delta^{\prime}(\sigma-\sigma^{\prime})$ except for one sector, which is $\{\chi_{-1}(\sigma),\chi_1(\sigma^{\prime})\}_{PB} = X^{\prime}(\sigma) \cdot P(\sigma^{\prime}) ~\delta^{\prime}(\sigma-\sigma^{\prime})$; 1d revised Simple harmonic motion angular frequency added 52 characters in body; edited tags; edited title 1d revised Diagonalisation: Schmidt vs eigenvalue - when to use which? Please dont introduce new tags unless necessary 1d revised How would one attach black hole to starship in the Black hole Starship model? edited tags 1d comment Rotation of Spacetime $\Rightarrow$ Change in orbit/path Comment to the post (v2): Perhaps OP is asking if the spin of a lone black hole leads to a Magnus effect or curveball, so to speak? If that's the question then the answer is no. 1d revised On a AC to DC adapter there are +12v wire with 24A and -12v have 0.5A. How many amp this adapter will provide in total? edited tags 1d revised Intuitive understanding of vector spaces added 1 character in body; edited tags; edited title 1d reviewed Leave Closed When light reflects from a medium of lower index of reflection to a medium of higher index of refraction, why does the light undergo a phase shift? 1d revised When light reflects from a medium of lower index of reflection to a medium of higher index of refraction, why does the light undergo a phase shift? added 5 characters in body; edited tags 1d revised Question about the apparent loophole in principle of least action added 462 characters in body 1d answered Question about the apparent loophole in principle of least action 1d revised Question about the apparent loophole in principle of least action edited tags 1d revised Scale invariance and stress energy tensor added 183 characters in body; edited tags 1d revised What are the calculations specifically needed for High Altitude Ballooning? deleted 8 characters in body; edited tags 1d revised Difference between stiffness and damping? edited tags