Chern numbers of terminal threefolds

Abstract

Let X be a smooth threefold. We show that if $X_i⇢X_{i+1}$ is a flip which appears in the $K_X$-MMP, then $c_1(X_i{)}^3-c_1(X_{i+1}{)}^3$ is bounded by a constant depending only on $b_2(X)$.

Final version (to appear in IMRN)