Problems / combinatorics
combinatorics / Graph theory
Erdős Problem #571: rational exponents for bipartite Turán numbers
For every rational α satisfying
1≤α<2,
the Lean theorem constructs some finite q and a bipartite graph
G:SimpleGraph(Finq)
such that
ex(n;G)=Θ(nα)
as n→∞.
This resolves the single-graph rational-exponents conjecture. Earlier work of Bukh and Conlon proved the corresponding statement only for a finite family of forbidden bipartite graphs, and subsequent work realized many large classes of individual rational exponents. Astra's theorem covers every rational α∈[1,2) with one forbidden graph for each exponent.