Harmonic Oscillator in Dirac Theory

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The discussion focuses on the resolution of the harmonic oscillator within the context of Dirac Theory, highlighting the challenges of reconciling non-relativistic concepts with Lorentz covariance. It emphasizes that Dirac's equation pertains to a Dirac spinor field operator, which leads to the interpretation of negative energy solutions as antiparticles, complicating the analysis to a many-particle problem. For single-particle solutions, one must project out the antiparticle component to derive the Pauli equation, which accounts for interactions with external electromagnetic fields. A scalar potential is provided to illustrate the non-relativistic framework, but it is noted that this approach has limitations under certain conditions. Overall, the conversation underscores the complexity of integrating harmonic oscillators into relativistic quantum mechanics.
eones
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Hello everyone,

i'm looking for anypaper or such kind of thing that explain the resolution of the harmonic oscillator in the Dirac Theory.

I have worked with the exact spin symmetry. I feel like a fish out the water and I'm sure that there are lot of bibliography about this area, but i promise i didn't find anything.

Thanks since now,
and may the force be with you!
 
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What do you mean by resolution? Also, you may have more luck getting replies in the Advanced Physics section (if this is related HW), or in the Quantum Physics section (if you simply want a reference).
 
The problem with the term in the title is that "harmonic oscillator" refers to the non-relativistic concept of a potential energy as a function of coordinates, which is manifestly Lorentz non-covariant, and Dirac's equation, which is a fully Lorentz covariant quantity.

Also, the proper meaning of Dirac's equation is that is non-quantum equation of motion for a Dirac spinor field operator in second quantization. This reinterprets the negative energy solutions as antiparticles. But, the problem essentially becomes a many-particle one.

If you are only interested in single-particle solutions, then you must project out the antiparticle component from the Dirac 4-spinor, to get the Pauli 2-spinor. The equation it obeys is Pauli equation, which already incorporates the interaction with an external electromagnetic field of a charged fermion.

Just take a scalar potential:
<br /> \varphi(x) = \frac{\mu^3 \, c^4}{2\, q \, \hbar^3} x^2<br />
where q is thecharge of the particle, and \mu has a dimension of mass. Of course, this non-relativistic equation is only valid when:
<br /> q \varphi(x) \ll m c^2 \Rightarrow \vert x \vert \ll \sqrt{\frac{2 m}{\mu}} \, \frac{\hbar}{\mu \, c}<br />
 
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Well, this isn't exactly what I am looking for, but its given me an idea anyway, so thank you very much for your time and effort.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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