Equipartition's energy theorem

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Discussion Overview

The discussion centers on the applicability of the equipartition's energy theorem in classical statistics, particularly when considering different Hamiltonians. Participants explore its validity in various contexts, including potential-free systems and more complex Hamiltonians.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions the validity of the equipartition's energy theorem when applied to Hamiltonians beyond the standard form, such as H=|p|c or those with complex potentials.
  • Another participant asserts that equipartition of energy is only valid for potential-free systems and suggests looking into the Virial Theorem for further insights.
  • It is noted that the theorem appears to hold for harmonic potentials at high temperatures, referencing specific heats of solids in the harmonic approximation.
  • A participant mentions that deriving results for Hamiltonians like H=|p| or H=p^4 in 1-D is straightforward, but expresses uncertainty about the complexity in 3-D cases.
  • One participant introduces the concept of a more general equipartition theorem that may apply in broader situations than the usual case, linking to additional resources for clarification.

Areas of Agreement / Disagreement

Participants express differing views on the conditions under which the equipartition theorem is valid, indicating that multiple competing perspectives remain without a consensus on its applicability to complex Hamiltonians.

Contextual Notes

Limitations include the dependence on specific forms of Hamiltonians and the conditions under which the equipartition theorem is applied, such as temperature and potential considerations.

Talker1500
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Hi,

I'm reading about the equipartition's energy theorem (classical statistics), and I was wondering about its validity when applied to different hamiltonians.

The usual case, H=p ^2/2m, it yields 3/2KT in 3D, but what about more complicated H? Like H=|p|c, or a H with a complex V? would the theorem still be available for use?

Thanks
 
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Equipartition of energy is only valid for a potential free system.

Beyond that you may want to look up the Virial Theorem
 
In 1-D is isn't too hard to derive the result for the cases H = |p|, or H = p^4. The derivation closely follows that of the quadratic case. In 3-D I suspect it is much more complicated, but I am often wrong!

jason
 

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