Conjectures by Paul Erdős

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The mathematician Paul Erdős made many conjectures in various areas of mathematics in his work .

Assumptions about number theory

just the solutions and has.
has a natural number solution for every natural number .
Let us consider the set S of all natural numbers n with the following property:
For every natural number k with k > 0 and 2 k < n , n - 2 k is a prime number .
Then S certainly contains the numbers .
For example, 45 in S because the numbers , , , , all prime numbers.
The conjecture now says that S only consists of these 7 numbers.
Until this assumption has been recalculated, i.e. H. there are certainly no numbers in S other than those mentioned that are less than 277 .
Every number n in S (except 4) automatically yields a prime number twin , namely .
See also: Follow A039669 in OEIS
  • Erdős divergence conjecture : It says that for every infinite sequence of the numbers +1 and −1 there are equidistant samples of finite length that add up to a sum of any magnitude. Terence Tao presented evidence in 2015.
  • Erdős-Woods conjecture : any whole number is given . Then there is a positive integer such that it is uniquely determined by the list of prime factors of .

Conjectures on graph theory

  • Erdős-Faber-Lovász conjecture: A graph that is a union of complete graphs with nodes that have at most one node in common in pairs is -chromatic.
  • Erdős-Gyárfás conjecture: Every graph whose vertices are all at least degree 3 contains a circle whose length is a power of two.

Assumptions about the Ramsey theory

Many conjectures, which come from Erdős or in which Erdős was involved, concern the area of ​​the Ramsey theory and in particular the Ramsey numbers . The Bondy and Erdős conjecture and the Erdős-Sós conjecture are outstanding examples .

Web links

Individual evidence

  1. Chris Cesare: Maths whiz solves a master's riddle . Nature News, September 25, 2015.