Generalized Prokhorov–Shokurov conjecture for generalized pairs

Let (X,B+M)(X',B'+M') be a generalized sub-pair with data XXX\to X' and MM, where BB', MM' and MM are Q\mathbb{Q}-divisors. Let f ⁣:XZf\colon X'\to Z' be a contraction such that

KX+B+MQ,f0.K_{X'}+B'+M'\sim_{\mathbb{Q},f}0.

Assume that MM is semi-ample, let cc be the minimum positive integer such that cM|cM| is basepoint-free, and assume that (X,B+M)(X',B'+M') is generalized klt over the generic point of ZZ'. Generalized Prokhorov–Shokurov conjecture. The moduli b-divisor MZ\mathbf{M}_{Z'} is b-semi-ample; for the generic fiber XηX'_\eta of ff, there is an integer I0I_0 depending only on dimXη\dim X'_\eta, the multiplicities of BhB^h, and cc such that

I0(KXη+Bη+Mη)0,I_0(K_{X'_\eta}+B'_\eta+M'_\eta)\sim 0,

where the representative of MM' may be replaced within its Q\mathbb{Q}-linear equivalence class; and MZ\mathbf{M}_{Z'} is effectively b-semi-ample: there is a positive integer I1I_1 depending only on the dimension of XX', the horizontal multiplicities of BB, and cc such that I1MZI_1\mathbf{M}_{Z'} is very b-semi-ample, namely I1MZ=LI_1\mathbf{M}_{Z'}=\overline{L} for a basepoint-free divisor LL on some birational model of ZZ'. This is proposed as a generalization of the Prokhorov–Shokurov conjecture in the setting of generalized pairs; its status is not resolved in the supplied source context.

Sources & referencesView supporting material

Primary source

Stefano Filipazzi, “On a generalized canonical bundle formula and generalized adjunction”, arXiv:1807.04847 (2019).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.