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Help in understanding the singular system of linear forms and non escape of mass

Okay, these are just basic technical tidbits. Unsure if anything here is of research level. $SO(n)$ acts transitively on the sphere of $\mathbb{R}^{n}$ (there's a slight ambiguity about $0$, but I gue …
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2 votes

Geodesics on hyperbolic surfaces whose closures have arbitrary Hausdorff dimension

Show that for a Bernoulli system, there exists ergodic (Bernoulli) measures of any given entropy (between 0 and full entropy). Pick such a measure with appropriate entropy as you would like. Recall t …
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1 vote

The (last step of the) proof that the set of badly approximable matrices has measure zero

Notice that every $m\in SL_{n}(\mathbb{R})$ can be written as $m=u\cdot q$, where $q$ is an ``opposite horospherical'' (maybe with center), namely it is not getting expanded by the $g_{t}$ action. The …
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1 vote

How large is the set of unimodular lattices whose sucesssive minima cannot be attained by a ...

Edit 2 - Definitely the set of lattices spanned by their shortest vectors is of positive measure. For each such lattice $\Lambda \in SL_{n}(\mathbb{R})/SL_{n}(\mathbb{Z})$, there exists $\epsilon=\eps …
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Equidistribution of the orbit $\{\text{diag}(t^a,t^{-a})\Lambda \}_{t>0}$ for a.e. $\Lambda\...

This thing cannot hold no matter what. As Echo rightfully commented, the expression doesn't even compile when $t=0$. It is true one might temper the integral away from $0$, but that's not what you ask …
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2 votes

How to show the geodesic orbit of a badly approximable number are/are not homogeneously equi...

A number is in BA if its orbit is bounded. Any such orbit closure must contain a full $A=\langle g_t\rangle$ orbit. By examining the possible subgroups, any such hypothetical $H$, as a stability group …
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8 votes

Has dynamics on $G/\Gamma$ ever been used to prove interesting things about $\Gamma$?

There's a nice proof by Margulis showing that arithmetic subgroups are indeed lattices using the famous Dani-Margulis non-divergence theorem. Actually if you will investigate Ratner's original formula …
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The Hausdorff codimension of singular matrices vs. the Hausdorff codimension of points with ...

It is evident that the singular vectors are defined as the ``$u_{A}$-part which is $g_{t}$ divergent in the future'', this gives $m\cdot n$ ($=\dim \left(u_{A}\right)$) minus the dimension of the sing …
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1 vote

The closure of the orbit of an irrational grid contains the fiber

First of all, $Y$ is not called the “grid space”. It is sometimes called the affine space and can be identified with a quotient of the affine group $\operatorname{ASL}_{n}$, namely the semi-direct pro …
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