Probability of Empty Intersection of Randomly Chosen Planes?

Click For Summary
SUMMARY

The discussion centers on the probability of the empty intersection of half-spaces defined by randomly chosen vectors in the set x ∈ {-1, 1}^n. Specifically, it addresses the condition under which the intersection p(x_1) ∩ ... ∩ p(x_{n+1}) equals the empty set, emphasizing that this occurs when at least two vectors in the set {x_1, ..., x_{n+1}} are anti-parallel. The conversation clarifies that empty intersections can exist without the presence of opposite vectors, challenging common assumptions about vector orientations in high-dimensional spaces.

PREREQUISITES
  • Understanding of vector spaces and half-spaces in n-dimensional geometry.
  • Familiarity with the concept of anti-parallel vectors.
  • Knowledge of probability theory, particularly in relation to random selections.
  • Basic comprehension of linear algebra concepts.
NEXT STEPS
  • Research the properties of half-spaces in n-dimensional geometry.
  • Study the implications of anti-parallel vectors in probability theory.
  • Explore the concept of random vector selection and its applications in high-dimensional spaces.
  • Learn about geometric probability and its relevance to intersections of sets.
USEFUL FOR

Mathematicians, statisticians, and researchers in fields involving high-dimensional geometry and probability theory, particularly those interested in the behavior of random vectors and their intersections.

Dragonfall
Messages
1,023
Reaction score
5
Let [itex]x \in \{-1, 1\}^n[/itex] and let [itex]p(x) = \{w \in \mathbb{R}^n : x \cdot w > 1\}[/itex]. What is the probability that [itex]p(x_1) \cap \ldots \cap p(x_{n+1}) = \emptyset[/itex] given that [itex]x_i[/itex] are chosen uniformly at random?
 
Physics news on Phys.org
##p(x)## is not a plane. It is a half-space. If you insist on the symbolical formulation, then the question boils down to the probability of having at least two vectors in ## \{ x_1, \ ... \ , x_{n + 1} \} ## that are anti-parallel.
 
No, it's possible to have empty intersection without a pair of opposite vectors.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 9 ·
Replies
9
Views
3K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 1 ·
Replies
1
Views
3K
Replies
15
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 9 ·
Replies
9
Views
2K