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If I am given a system, which I might have to describe using a generalized entropy, like the "q-deformed" Tsallis entropy, do I have to fit q from experiment or might I know it beforehand? How do I know the parameter q and/or how can I possibly obtain the degree of non-extensitivity via experiment? How can I measure the entropy of a part of the system, if the system is non-extensive?


After some browsing I think the answer might be related to the fact, that for q-deformed entropy, the most probable distribution is not the Gaussian, but seems to be the q-deformed Gaussian:

Then I played around a bit:

Maybe one applies such an entropy concept if one comes across a distribution of such type, but that's only a guess. And I don't see why one would/could conclude non-extensitivity from a distribution?!

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Can you give one example? I am struggling to find a single case which is described by this thing. – Ron Maimon Oct 10 '11 at 6:04
The kappa velocity distribution function is related to the Tsallis q-distribution and has been heavily researched in space plasma physics. – honeste_vivere Mar 7 at 18:00

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