Log Canonical Minimal Model Program for corank one foliations on Threefolds
Priyankur Chaudhuri, Roktim Mascharak
TL;DR
The paper develops a comprehensive log canonical MMP for corank one foliations on threefolds with klt-type boundaries and extends it to NQC generalized foliated quadruples. It establishes the cone and contraction theorems, proves the existence of flips, and shows termination of foliated MMP in dimension three, then extends the framework to gfqs including a basepoint free theorem and finite log geography. A key outcome is that any two foliated minimal models can be connected by a sequence of flops, and the number of minimal/log canonical models in a boundary-polarized setting is finite. An appendix broadens contraction theory to algebraic spaces without assuming a klt boundary. This work advances birational geometry of foliations and provides toolsets for moduli and boundedness questions in foliated settings.
Abstract
If $(X, \mcF, \D)$ is a projective rank two foliated log canonical triple such that $(X,B)$ is klt for some $0 \leq B \leq \D$, we show that we can run a $(K_\mcF +Δ)$-MMP and any such MMP terminates with either a minimal model or Mori fiber space. Next, we establish a Bertini type lemma and adjunction for generalized foliated quadruples. Using these, we extend the full log canonical MMP to the setting of rank two NQC generalized foliated quadruples. Finally, we apply the generalized MMP to study the relation between different minimal models, namely, any two minimal models of a given foliated log canonical triple can be connected by a sequence of flops and in the boundary polarized case, the minimal models are good and only finitely many in number.
