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Dynamical systems on measure spaces, invariant measures, ergodic averages, mixing properties.

3 votes

When is there a natural Riemannian metric whose measure preserves a self-diffeomorphism?

An important necessary condition is that on periodic points, the determinant in the period must be one (that is not hard). I believe that what you ask has to do with Theorem 5.1.13 of Katok-Hasselbla …
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10 votes
Accepted

Is the composition of non-wandering maps still non-wandering?

To the first question the answer is negative. There are two homeomorphisms of the circle with irrational rotation number such that their composition is Morse-Smale (in fact, you can multiply two $2\ti …
rpotrie's user avatar
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1 vote

Inflating/Deflating diffeomorphism

Not sure if it is related, but in Lemma 1 of this paper (A.Avila, J. Bochi, A C1 generic map has no invariant absolutely continuous probability measure) it is proved that if a map has no invariant abs …
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0 votes

Transitive shifts with multiple fully supported MMEs

I believe that combining these two papers, you get an answer: http://arxiv.org/abs/0906.2176 and http://arxiv.org/abs/1010.3372. In the first one it is shown that partially hyperbolic sets with one …
rpotrie's user avatar
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7 votes

Examples of transformations which are weak-mixing but not strong-mixing

I think a good example (which may not qualify as consise, but does as self contained) is given in the famous paper of Anosov and Katok. There they construct smooth diffeomorphisms of the disc being we …
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7 votes

Product Measure Only Possible Measure?

The answer is no. A trivial example is to concentrate the measure in a "periodic orbit", this will give an invariant measure for the shift. But there are a whole lot of invariant measures (including …
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3 votes

orbits in locally compact group

For Lie groups, the only one with this property is $S^1$. To see this, consider a one parameter subgroup given by exponential of a vector in the lie algebra, and the closure of this subgroup should …
rpotrie's user avatar
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2 votes

Does ergodic theorem apply to trajectories outside of attractor?

The key word you are looking for is "physical measures", sometimes known as SRB measures (because of the result.that coudy mentions). See https://link.springer.com/article/10.1023/A:1019762724717 A re …
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3 votes

Lebesgue entropy zero and positive topological entropy

I do not have an direct answer but since I fear the answer might not be known and you also ask for related stuff let me mention a couple of results. In the $C^1$ case, Mañe-Bochi's result asserts th …
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5 votes
Accepted

An example of an SRB measure which is not a physical measure

You can just take an Anosov map on $T^2$ and multiply by identity on the circle. Then, you will have SRB measures supported on $T^2 \times pt$ which are not physical.
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2 votes
Accepted

Real analytic ergodic diffeomorphisms of the two sphere

In $S^2$ it is possible to construct such an example by a quite different method (not as a limit of rotations) which is indeed Bernoulli with respect to Lebesgue. The idea is to quotient the cat map …
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4 votes

Ergodicity of the action of $\operatorname{SL}(n,\mathbb R)$ on $\operatorname{SL}(n,\mathbb...

The question is why a measurable function which is invariant under the action of all $g \in G$ must be a.e. constant. But since the action of $G$ is transitive on $G/\Gamma$ it is easy to see that thi …
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