**Are you an EPFL student looking for a semester project?**

Work with us on data science and visualisation projects, and deploy your project as an app on top of GraphSearch.

Concept# Minimal model program

Summary

In algebraic geometry, the minimal model program is part of the birational classification of algebraic varieties. Its goal is to construct a birational model of any complex projective variety which is as simple as possible. The subject has its origins in the classical birational geometry of surfaces studied by the Italian school, and is currently an active research area within algebraic geometry.
The basic idea of the theory is to simplify the birational classification of varieties by finding, in each birational equivalence class, a variety which is "as simple as possible". The precise meaning of this phrase has evolved with the development of the subject; originally for surfaces, it meant finding a smooth variety for which any birational morphism with a smooth surface is an isomorphism.
In the modern formulation, the goal of the theory is as follows. Suppose we are given a projective variety , which for simplicity is assumed non-singular. There are two cases based on its Kodaira dimension, :
We want to find a variety birational to , and a morphism to a projective variety such that with the anticanonical class of a general fibre being ample. Such a morphism is called a Fano fibre space.
We want to find birational to , with the canonical class nef. In this case, is a minimal model for .
The question of whether the varieties and appearing above are non-singular is an important one. It seems natural to hope that if we start with smooth , then we can always find a minimal model or Fano fibre space inside the category of smooth varieties. However, this is not true, and so it becomes necessary to consider singular varieties also. The singularities that appear are called terminal singularities.
Enriques–Kodaira classification
Every irreducible complex algebraic curve is birational to a unique smooth projective curve, so the theory for curves is trivial. The case of surfaces was first investigated by the geometers of the Italian school around 1900; the contraction theorem of Guido Castelnuovo essentially describes the process of constructing a minimal model of any surface.

Official source

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Related people (3)

Related concepts (15)

Related publications (14)

Related units (1)

Related lectures (5)

Flip (mathematics)

In algebraic geometry, flips and flops are codimension-2 surgery operations arising in the minimal model program, given by blowing up along a relative canonical ring. In dimension 3 flips are used to construct minimal models, and any two birationally equivalent minimal models are connected by a sequence of flops. It is conjectured that the same is true in higher dimensions. Minimal model program The minimal model program can be summarised very briefly as follows: given a variety , we construct a sequence of contractions , each of which contracts some curves on which the canonical divisor is negative.

Cone of curves

In mathematics, the cone of curves (sometimes the Kleiman-Mori cone) of an algebraic variety is a combinatorial invariant of importance to the birational geometry of . Let be a proper variety. By definition, a (real) 1-cycle on is a formal linear combination of irreducible, reduced and proper curves , with coefficients . Numerical equivalence of 1-cycles is defined by intersections: two 1-cycles and are numerically equivalent if for every Cartier divisor on . Denote the real vector space of 1-cycles modulo numerical equivalence by .

Canonical ring

In mathematics, the pluricanonical ring of an algebraic variety V (which is nonsingular), or of a complex manifold, is the graded ring of sections of powers of the canonical bundle K. Its nth graded component (for ) is: that is, the space of sections of the n-th tensor product Kn of the canonical bundle K. The 0th graded component is sections of the trivial bundle, and is one-dimensional as V is projective. The projective variety defined by this graded ring is called the canonical model of V, and the dimension of the canonical model is called the Kodaira dimension of V.

Varieties with nef anti-canonical: Surjective Albanese

Presents a proof that smooth projective varieties with nef anti-canonical divisor have surjective Albanese morphism.

Varieties of Anticanonical Surjective Albanese

Covers the main result regarding varieties of anticanonical surjective Albanese.

Adjunctions and ApplicationsMATH-510: Algebraic geometry II - schemes and sheaves

Covers adjunctions, projective varieties, regularity, and valuative criteria in algebraic geometry.

We use birational geometry to show that the existence of rational points on proper rationally connected varieties over fields of characteristic 0 is a consequence of the existence of rational points on terminal Fano varieties. We discuss several consequenc ...

Zsolt Patakfalvi, Joseph Allen Waldron

We establish the Minimal Model Program for arithmetic threefolds whose residue characteristics are greater than five. In doing this, we generalize the theory of global F-regularity to mixed characteristic and identify certain stable sections of adjoint lin ...

,

We show that mixed-characteristic and equicharacteristic small deformations of 3-dimensional canonical (resp., terminal) singularities with perfect residue field of characteristic p>5 are canonical (resp., terminal). We discuss applications to arithmetic a ...