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| visits | member for | 1 year, 7 months |
| seen | 2 days ago | |
| stats | profile views | 193 |
Just here to learn and share.
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Oct 25 |
answered | Is Gravity Energy? |
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Oct 25 |
answered | Are there any quantities in the physical world that are inherently rational/algebraic? |
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Oct 25 |
answered | Usefullness of an only qualitative understanding of momentum? |
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Oct 24 |
awarded | Teacher |
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Oct 24 |
accepted | Linearizing Quantum Operators |
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Oct 24 |
answered | How is squeezed light produced? |
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Oct 24 |
awarded | Supporter |
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Oct 24 |
awarded | Scholar |
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Oct 24 |
accepted | Linearizing Quantum Operators |
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Oct 24 |
comment |
Linearizing Quantum Operators Ron, thank you. I will check out those references. How does the background field method justify decoupling fluctuations from the mean-field to solve them separately? This is the real problem I am having. It almost seems like a vector space formalism, only in this case you describe the space of $\hat{A}$ in terms of two basis, i.e $I$ and $\Delta\hat{a}$. Sorry about my obsession with Groups/Vector Spaces. :) |
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Oct 24 |
answered | Hyperfine structure vs Lamb shift in the hydrogen atom |
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Oct 24 |
comment |
Linearizing Quantum Operators Sorry guys. I am new here and I was not sure which site would be appropriate. I saw tons of F=ma questions on the Physics site, so I was not sure if my question would be answered there. Both versions have given me different answers, so thank you. |
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Oct 24 |
comment |
Linearizing Quantum Operators Thank you for the answer. Can you kindly point me to a book or an article where I can read about this formalism? I have no background in QFT beyond second quantization. |
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Oct 23 |
comment |
Linearizing Quantum Operators I am aware of the standard calculus reasoning, i.e a Taylor series expansion about the mean and dropping higher order terms, but that does not necessarily mean that any functional expansion is separable. I mean, the author states that a diff eq:$$\frac{d\hat{A}_1}{dz}=-\alpha \hat{A}_1^{\dagger }\hat{A}_2 e^{-{i\Delta kz}}$$ can be solved by treating the average and fluctuations separately. I don't see how you can decouple them? |
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Oct 23 |
comment |
Linearizing Quantum Operators I don't see how this can be justified based on calculus reasoning alone? The first thing that comes to my mind is Cosets, but I am not sure how to take that anywhere. |
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Oct 23 |
comment |
Linearizing Quantum Operators Greetings Vladimir, as you have suggested, it makes sense from a pure calculus point of view (continuous and differentiable functions), but would it necessarily apply in the case of quantum operators? I am looking for a Group theoretic reason to justify this operation. The problem I am having is that the author in (pra.aps.org/abstract/PRA/v49/i3/p2157_1) decomposes $$\frac{d\hat{A}_1}{dz}=-\alpha \hat{A}_1^{\dagger }\hat{A}_2 e^{-{i\Delta kz}}$$ into separable differential equations, one involving only the average values and the other involving only fluctuations. |
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Oct 23 |
awarded | Student |
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Oct 23 |
asked | Linearizing Quantum Operators |
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Oct 23 |
asked | Linearizing Quantum Operators |
