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Mar
24
answered Galilean, SE(3), Poincare groups - Central Extension
Mar
20
comment Lie group of Schrodinger Wave equation
@user35952 I'll try to answer your new question soon, I'll try to clarify the previous "Poincare group vs Galilean group" answer
Mar
19
revised Lie group of Schrodinger Wave equation
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Mar
19
revised Lie group of Schrodinger Wave equation
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Mar
19
answered Lie group of Schrodinger Wave equation
Mar
16
revised Significance of magnetic translation operator defined in fractional QHE's description
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Mar
16
answered Significance of magnetic translation operator defined in fractional QHE's description
Mar
13
awarded  Nice Answer
Mar
13
comment Which symmetric pure qudit states can be reached within local operations?
@Piotr Migdal Thank you very much
Mar
13
awarded  Nice Answer
Mar
9
comment Lie algebra of axial charges
@gian_25 The matrix representation is just the 4-dimensional fundamental representation of $SO(4) = SU(2) \times SU(2)$, denoting the indices of the 4-space corresponding to $(\sigma, \pi_1, \pi_2, \pi_3)$ by $0,1,2,3$. Then$ (T^{V}_i)_{jk} = i \epsilon_{ijk}, (T^{(A)}_i)_{jk} = i (\delta_{ji}\delta_{k0}+ \delta_{ki}\delta_{i0})$. Please observe that the commutator of two axial generators is a vector generator.
Mar
9
answered Lie algebra of axial charges
Mar
6
comment How to prove the covariant derivative cannot be written as an eigendecomposition of the partial derivative?
@MBN there are partial results, for example Ellis meghnad.iucaa.ernet.in/~tarun/pprnt/topology/… mentions a result by Clarke that every 3+1 noncompact space-time can be isometrically embedded into a flat $\mathbb{R}^{87,3}$.
Mar
6
comment How to prove the covariant derivative cannot be written as an eigendecomposition of the partial derivative?
@linuxfreebird. In the case when the transformation is invertible, then your analysis is correct, but this special case is not really interesting in general relativity. I updated my answer with a detailed explanation.
Mar
6
revised How to prove the covariant derivative cannot be written as an eigendecomposition of the partial derivative?
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Mar
6
comment Quantization of electrostatic $\vec E$ field?
@webb corrected and cited. But this does not change the argument: a nonvanishing commutation relation between any component of the electric and magnetic fields imply nonzero uncertainty.
Mar
6
revised Quantization of electrostatic $\vec E$ field?
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Mar
5
revised Quantization of electrostatic $\vec E$ field?
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Mar
5
answered Quantization of electrostatic $\vec E$ field?
Mar
5
answered How to prove the covariant derivative cannot be written as an eigendecomposition of the partial derivative?