Proving Stable Set Size in Graphs with Average Degree d

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SUMMARY

A graph with an average degree of d contains a stable set of cardinality at least n/(2d). This conclusion is derived using probabilistic methods, specifically by calculating the expected number of stable sets. If all stable sets were smaller than n/(2d), the expectation would be bounded, which contradicts the established result. This analysis confirms the existence of larger stable sets in graphs with average degree d.

PREREQUISITES
  • Understanding of graph theory concepts, specifically stable sets.
  • Familiarity with probabilistic methods in combinatorics.
  • Knowledge of average degree calculations in graphs.
  • Basic principles of expectation in probability theory.
NEXT STEPS
  • Study the properties of stable sets in graph theory.
  • Learn about probabilistic methods in combinatorial optimization.
  • Explore the concept of average degree in various types of graphs.
  • Investigate expectation values and their applications in probability theory.
USEFUL FOR

Mathematicians, computer scientists, and students studying graph theory or combinatorial optimization, particularly those interested in probabilistic methods and their applications in proving theoretical results.

Dragonfall
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Homework Statement



Show using a probabilistic method that a graph with average degree d has a stable set of cardinality at least n/(2d).

I can't think of a probabilistic method that will do this.
 
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What is a stable set?

Work out the expected number of stable sets, I suppose - if all stable sets were of size less than n/2d, then that might be a bound on the expectation - show the bound is exceeded.

But that is just a guess as to the style of how probabilistic graph theory works - I've never answered a question on it and read precisely on paragraph about it once, so don't trust me.
 

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