We study the Lovasz number theta along with two further SDP relaxations $\thetI$, $\thetII$
of the independence number and the corresponding relaxations of the
chromatic number on random graphs G(n,p). We prove that \theta is
concentrated about its mean, and that the relaxations of the chromatic
number in the case ... more >>>

Let $\phi$ be a 3CNF formula with n variables and m clauses. A
simple nonconstructive argument shows that when m is
sufficiently large compared to n, most 3CNF formulas are not
satisfiable. It is an open question whether there is an efficient
refutation algorithm that for most such formulas proves ... more >>>