printable pdf
比利时vs摩洛哥足彩 ,
university of california san diego

****************************

combinatorics seminar (math 269)

sam spiro

rutgers university

clique and berge supersaturation for $k_{2,t}$.

abstract:

a famous conjecture of erd\h{o}s and simonovits says that if $g$ is an $n$ vertex graph with much more than $\ex(n,f)$ edges, then $g$ contains about as many copies of $f$ as the random graph of the same density.  in this talk we show that several natural generalizations of this conjecture fails to be true.  in particular, we show that for large $t$, there exist $n$ vertex graphs with $\theta(kn^{3/2})$ triangles such that $g$ contains a total of $k^tn^{3/2+o(1)}$ copies of $k_{2,t}$ (with the random graph of the same triangle density containing $\theta(k^{2t/3}n^2)$ copies), and we show that this bound is essentially best possible for $k\le n^{1/2t}$. our constructions rely on solving certain unbalanced bipartite tur\'an problems using random polynomial graphs.  this is joint work with quentin dubroff, benjamin gunby, and bhargav narayanan.  
 
 

host: brendon rhoades

may 9, 2023

4:00 pm

apm 6402

****************************