Boltzmann Entropy for micro state or macro state?

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SUMMARY

The discussion centers on the interpretation of Boltzmann entropy in relation to microstates and macrostates, specifically questioning whether interchanging particle labels while maintaining the occupancy numbers {ni} results in a new microstate. The Boltzmann entropy is defined as S=k log(Ω{ni}), where Ω represents the number of microstates corresponding to the occupancy numbers. The conclusion drawn is that if interchanging particle labels does not create a new microstate, then the entropy would be zero, indicating only one microstate exists for the given occupancy in gamma space. The role of momentum in defining distinguishability among particles is also emphasized.

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  • Understanding of Boltzmann entropy and its mathematical formulation
  • Familiarity with microstates and macrostates in statistical mechanics
  • Knowledge of counting principles in multi-dimensional spaces
  • Concept of particle indistinguishability and its implications in thermodynamics
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  • Explore the implications of particle indistinguishability in quantum mechanics
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  • Investigate the concept of degeneracy in thermodynamic systems
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bikashkanungo
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From theory, we know that Boltzmann entropy for a given distribution, defined through a set of occupancy numbers {ni}, of the macrostate M, is given by:
S=k log(Ω{ni})
where omega is the number of microstates for the previously given set of occupancy number, {ni} . Assuming that the system is in equilibrium, we get omega to be predominantly the number of microstates which fill up the entire 6ND gamma space.

Using counting principles in the 6 dimensional mu space we get omega to be equal to product(1/[factorial(ni)]).

My question is would interchanging particle labels (such that {ni} does not change) result in a new microstate? If yes, it means that particles are no longer indistinguishable. If no, then entropy becomes zero since there is just 1 microstate for the given {ni} in gamma space.

I would appreciate if anyone clears this doubt.
 
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I think energy does not completely define a microstate. Momentum does. So each energy state has a number of momentum states and these particles are distinguishable by their momentum (but again, not by any "identity"). You have to take this degeneracy into account.
 

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