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Timeline for Convergence of an iterated sequence

Current License: CC BY-SA 3.0

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Mar 9, 2018 at 21:44 history bumped CommunityBot This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
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Dec 9, 2017 at 20:33 history bumped CommunityBot This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
Nov 9, 2017 at 20:17 answer added Anthony Quas timeline score: 2
Nov 9, 2017 at 11:01 comment added user111097 @AnthonyQuas Could you please explain a bit more how the above arguments could be applied to the case $p\neq 1/2$? By the way, why do you assume the slope $|\epsilon|<1$? Thank you very much!
Nov 3, 2017 at 10:35 history edited YCor
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Nov 3, 2017 at 9:22 answer added user111097 timeline score: 0
Nov 3, 2017 at 6:07 history edited Martin Sleziak
removed deprecated (geometry) tag - see the tag info: http://mathoverflow.net/tags/geometry/info; if there are some other geometry-related tags which are suitable, please use some of them instead
Nov 3, 2017 at 1:39 comment added Anthony Quas It occurs to me that even for $p\ne1/2$, the subdivision is still determined by the slope, so this remains a one-dimensional problem (and the map is piecewise rational). It should be straightforward enough to answer your question then.
Nov 2, 2017 at 23:49 comment added Anthony Quas Any half-plane whose intersection with the square has measure 1/2 goes through the centre of the square (proof: rotate by 180 degrees around the centre of the square). This means that after step 1, the two pieces are completely defined by the slope of the line joining them. I will rewrite the square as $[-1/2,1/2]^2$. If the slope is $|\epsilon|<1$, I claim the barycentres of the pieces are at $\pm(-\epsilon/6,1/4-\epsilon^2/12)$. If my calcs are right, this shows the new slope is $2\epsilon/(3-\epsilon^2)$. So the slopes $\epsilon=\pm1$ are unstable fixpts; and $\epsilon=0$ is attracting.
Nov 2, 2017 at 23:35 comment added user111097 @AnthonyQuas Actually, this problem is linked to the Voronoi diagram that is used in solving an (semi-discrete) optimal transport problem, where the marginal distributions are given by $\mu=p\delta_{(x_1,y_1)}+(1-p)\delta_{(x_2,y_2)}$ and $\nu=\mathcal{Les}$
Nov 2, 2017 at 23:33 comment added user111097 @AnthonyQuas Thanks a lot for the quick reply. Could you please specify a bit more?
Nov 2, 2017 at 23:01 comment added Anthony Quas In the case where p=1/2, this is a one-dimensional problem: the line separating the barycentres always goes through (1/2,1/2). Have you studied convergence or otherwise in this setting?
Nov 2, 2017 at 21:32 history asked user111097 CC BY-SA 3.0