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rpotrie
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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 absolutely continuous probability measure, then, there exists a compact set $K$ of measure abitrarily close to $1$ which has an iterate with arbitrarily small measure.

Sorry if this has nothing to do, but from how I understood the question, at least this should be useful.

EDIT: Re-reading the question, I've noticed that you are maybe more concerned about iterates of balls. 

For this, it depends on what you want. For example, if you want, for any $\varepsilon$ a ball of smaller radius that has iterates with volume close to the manifold, it is easy to get (say, for example a north-south map). However, ifI believe this should be not what you are looking for.

If you look for every ball at a time, this won't be true in general, for, example, ifand let me rephrase your question (or at least the one I am responding to): Is there a homeomorphism $f$ such that given a ball $B$ and $\varepsilon>0$ there exists an integer $n$ such that $f^n(B)$ has measure larger than $1-\varepsilon$.

If $f$ is not transitive (or at least, you get a reppeling neighborhoodif it has at least two chain recurrence classes), then, there exists an open set such that $\overline{U} \subset f(U)$ so, if you won't aproach the total volumeconsider a ball in $\overline{U}^c$ it will never reach measure bigger than the complement of $U$. If

For $f$ is transitive, I believe you can manage to prove the samethere are also examples where this does not hold. For example, for conservative (that some balls won't increase their volume arbitrarily close to that of the manifold) but$f$, it trivially does not hold.

In other cases, I havewould presume that it is not an argument at the momenttrue (it is clear if it is volume preservingat least for ``tipical'' diffeomorphisms), and otherwisehowever, you will get some regions which are kind of ``repelling'')I don't know a proof nor an example.

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 absolutely continuous probability measure, then, there exists a compact set $K$ of measure abitrarily close to $1$ which has an iterate with arbitrarily small measure.

Sorry if this has nothing to do, but from how I understood the question, at least this should be useful.

EDIT: Re-reading the question, I've noticed that you are maybe more concerned about balls. For this, it depends on what you want. For example, if you want, for any $\varepsilon$ a ball of smaller radius that has iterates with volume close to the manifold, it is easy to get (say, for example a north-south map). However, if you look for every ball at a time, this won't be true in general, for, example, if $f$ is not transitive, you get a reppeling neighborhood, so you won't aproach the total volume never. If $f$ is transitive, I believe you can manage to prove the same (that some balls won't increase their volume arbitrarily close to that of the manifold) but I have not an argument at the moment (it is clear if it is volume preserving, and otherwise, you will get some regions which are kind of ``repelling'').

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 absolutely continuous probability measure, then, there exists a compact set $K$ of measure abitrarily close to $1$ which has an iterate with arbitrarily small measure.

Sorry if this has nothing to do, but from how I understood the question, at least this should be useful.

EDIT: Re-reading the question, I've noticed that you are maybe more concerned about iterates of balls. 

For this, it depends on what you want. For example, if you want, for any $\varepsilon$ a ball of smaller radius that has iterates with volume close to the manifold, it is easy to get (say, for example a north-south map). I believe this should be not what you are looking for.

If you look for every ball at a time, this won't be true in general, and let me rephrase your question (or at least the one I am responding to): Is there a homeomorphism $f$ such that given a ball $B$ and $\varepsilon>0$ there exists an integer $n$ such that $f^n(B)$ has measure larger than $1-\varepsilon$.

If $f$ is not transitive (or at least, if it has at least two chain recurrence classes), then, there exists an open set such that $\overline{U} \subset f(U)$ so, if you consider a ball in $\overline{U}^c$ it will never reach measure bigger than the complement of $U$.

For $f$ transitive, there are also examples where this does not hold. For example, for conservative $f$, it trivially does not hold.

In other cases, I would presume that it is not true (at least for ``tipical'' diffeomorphisms), however, I don't know a proof nor an example.

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rpotrie
  • 3.9k
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  • 27

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 absolutely continuous probability measure, then, there exists a compact set $K$ of measure abitrarily close to $1$ which has an iterate with arbitrarily small measure.

Sorry if this has nothing to do, but from how I understood the question, at least this should be useful.

EDIT: Re-reading the question, I've noticed that you are maybe more concerned about balls. For this, it depends on what you want. For example, if you want, for any $\varepsilon$ a ball of smaller radius that has iterates with volume close to the manifold, it is easy to get (say, for example a north-south map). However, if you look for every ball at a time, this won't be true in general, for, example, if $f$ is not transitive, you get a reppeling neighborhood, so you won't aproach the total volume never. If $f$ is transitive, I believe you can manage to prove the same (that some balls won't increase their volume arbitrarily close to that of the manifold) but I have not an argument at the moment (it is clear if it is volume preserving, and otherwise, you will get some regions which are kind of ``repelling'').

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 absolutely continuous probability measure, then, there exists a compact set $K$ of measure abitrarily close to $1$ which has an iterate with arbitrarily small measure.

Sorry if this has nothing to do, but from how I understood the question, at least this should be useful.

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 absolutely continuous probability measure, then, there exists a compact set $K$ of measure abitrarily close to $1$ which has an iterate with arbitrarily small measure.

Sorry if this has nothing to do, but from how I understood the question, at least this should be useful.

EDIT: Re-reading the question, I've noticed that you are maybe more concerned about balls. For this, it depends on what you want. For example, if you want, for any $\varepsilon$ a ball of smaller radius that has iterates with volume close to the manifold, it is easy to get (say, for example a north-south map). However, if you look for every ball at a time, this won't be true in general, for, example, if $f$ is not transitive, you get a reppeling neighborhood, so you won't aproach the total volume never. If $f$ is transitive, I believe you can manage to prove the same (that some balls won't increase their volume arbitrarily close to that of the manifold) but I have not an argument at the moment (it is clear if it is volume preserving, and otherwise, you will get some regions which are kind of ``repelling'').

Source Link
rpotrie
  • 3.9k
  • 24
  • 27

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 absolutely continuous probability measure, then, there exists a compact set $K$ of measure abitrarily close to $1$ which has an iterate with arbitrarily small measure.

Sorry if this has nothing to do, but from how I understood the question, at least this should be useful.