Skip to main content

All Questions

1 vote
1 answer
27 views

Can we randomly subdivide general convex sets "uniformly" in terms of volume?

I'm not sure how best to phrase my question. I'll explain first what I mean by the title. If we work on an interval $(a,b)$, then by choosing a number uniformly on this interval we divide the length &...
Np92's user avatar
  • 137
1 vote
0 answers
91 views

Convergence to an $\ell_p$ ball, of Steiner symmetrization of compact convex subsets of $\mathbb R^n$

Context. I'm working on a problem, and it seems Steiner symmetrization might just be the golden trick. But first, I must make sure the process will converge to an $\ell_p$ ball... Fix $p \in [1,\...
dohmatob's user avatar
  • 9,575
2 votes
1 answer
534 views

Probability that the convex hull of random points is a triangle

Question: Consider a fixed number $k > 3$ of random points in the plane, each independently distributed according to a 2D standard normal distribution. What is the probability that the convex hull ...
Nick Alger's user avatar
  • 19.1k
2 votes
1 answer
1k views

Boyd & Vandenberghe, Exercise 2.15g — Convexity of a region on the probability simplex

Exercise 2.15g of Boyd & Vandenberghe's Convex Optimization: On the probability simplex in $\mathbb{R}^n$ where each point $p = (p_1, p_2, p_3, \ldots, p_n)$ corresponds to a distribution for ...
Hsolo's user avatar
  • 21
13 votes
1 answer
550 views

Expected values of some properties of the convex hull of a random set of points

$N$ points are selected in a uniformly distributed random way in a disk of the unit radius. Let $P(N)$ and $A(N)$ denote the expected perimeter and the expected area of their convex hull. For what $N$...
Frida Mauer's user avatar
  • 1,249
1 vote
2 answers
356 views

Integral of convex set

Let $D$ be a convex set and $X_1,\dots,X_d$ be integrable random variables. If $X= (X_1,\dots,X_d)$ is in $D$ almost surely, why is it true that the vector $a= (\mathbb{E}X_1,\dots,\mathbb{E}X_d)$ ...
user90831's user avatar
  • 259
4 votes
0 answers
81 views

Random convex shapes containing a ball

I'm interested in the properties of randomly generated convex shapes in $n$-dimensional space. Suppose I were to generate $v$ uniformly distributed random points on the $n$-ball of radius $R$. What ...
ymbirtt's user avatar
  • 1,231
21 votes
2 answers
1k views

What is the probability of having a pentagon in 6 points

If the probability that $5$ random points in the plane whose horizontal coordinate and vertical coordinate are uniformly distributed on the interval $\left(0,1\right)$ occur to be the vertices of a ...
kejma's user avatar
  • 499
18 votes
1 answer
671 views

Expected size of subset forming convex polygon.

If there are $4$ random points in the plane whose horizontal coordinate and vertical coordinate are uniformly distributed on the interval $\left(0,1\right)$, what is the expected largest size (or ...
kejma's user avatar
  • 499