Birational geometry of the moduli space of quartic  surfaces

2019 ◽  
Vol 155 (9) ◽  
pp. 1655-1710
Author(s):  
Radu Laza ◽  
Kieran O’Grady
Keyword(s):  
Moduli Space ◽  
Moduli Spaces ◽  
Invariant Theory ◽  
Geometric Invariant Theory ◽  
Dimensional Case ◽  
Geometric Invariant ◽  
Type Iv ◽  
Log Canonical ◽  
Symmetric Varieties ◽  
The Relationship

By work of Looijenga and others, one understands the relationship between Geometric Invariant Theory (GIT) and Baily–Borel compactifications for the moduli spaces of degree-$2$ $K3$ surfaces, cubic fourfolds, and a few other related examples. The similar-looking cases of degree-$4$ $K3$ surfaces and double Eisenbud–Popescu–Walter (EPW) sextics turn out to be much more complicated for arithmetic reasons. In this paper, we refine work of Looijenga in order to handle these cases. Specifically, in analogy with the so-called Hassett–Keel program for the moduli space of curves, we study the variation of log canonical models for locally symmetric varieties of Type IV associated to $D$-lattices. In particular, for the $19$-dimensional case, we conjecturally obtain a continuous one-parameter interpolation between the GIT and Baily–Borel compactifications for the moduli of degree-$4$ $K3$ surfaces. The analogous $18$-dimensional case, which corresponds to hyperelliptic degree-$4$ $K3$ surfaces, can be verified by means of Variation of Geometric Invariant Theory (VGIT) quotients.

RELATIVE GEOMETRIC INVARIANT THEORY AND UNIVERSAL MODULI SPACES

1996 ◽  
Vol 07 (02) ◽  
pp. 151-181 ◽  
Author(s):  
YI HU
Keyword(s):  
Moduli Space ◽  
Moduli Spaces ◽  
Invariant Theory ◽  
Hilbert Scheme ◽  
Geometric Invariant Theory ◽  
Geometric Invariant ◽  
Coherent Sheaves ◽  
Ample Cone

We expose in detail the principle that the relative geometric invariant theory of equivariant morphisms is related to the GIT for linearizations near the boundary of the G-effective ample cone. We then apply this principle to construct and reconstruct various universal moduli spaces. In particular, we constructed the universal moduli space over [Formula: see text] of Simpson’s p-semistable coherent sheaves and a canonical rational morphism from the universal Hilbert scheme over [Formula: see text] to a compactified universal Picard.

scholarly journals Variation of geometric invariant theory quotients and derived categories

2019 ◽  
Vol 2019 (746) ◽  
pp. 235-303 ◽  
Author(s):  
Matthew Ballard ◽  
David Favero ◽  
Ludmil Katzarkov
Keyword(s):  
Moduli Spaces ◽  
Invariant Theory ◽  
General Framework ◽  
Derived Categories ◽  
Rational Curves ◽  
Geometric Invariant Theory ◽  
Geometric Invariant ◽  
Coherent Sheaves ◽  
Orthogonal Decompositions ◽  
The Relationship

Abstract We study the relationship between derived categories of factorizations on gauged Landau–Ginzburg models related by variations of the linearization in Geometric Invariant Theory. Under assumptions on the variation, we show the derived categories are comparable by semi-orthogonal decompositions and we completely describe all components appearing in these semi-orthogonal decompositions. We show how this general framework encompasses many well-known semi-orthogonal decompositions. We then proceed to give applications of this complete description. In this setting, we verify a question posed by Kawamata: we show that D-equivalence and K-equivalence coincide for such variations. The results are applied to obtain a simple inductive description of derived categories of coherent sheaves on projective toric Deligne–Mumford stacks. This recovers Kawamata’s theorem that all projective toric Deligne–Mumford stacks have full exceptional collections. Using similar methods, we prove that the Hassett moduli spaces of stable symmetrically-weighted rational curves also possess full exceptional collections. As a final application, we show how our results recover and extend Orlov’s σ-model/Landau–Ginzburg model correspondence.

scholarly journals GEOMETRIC INVARIANT THEORY FOR HOLOMORPHIC FOLIATIONS ON ℂℙ2 OF DEGREE 2

2010 ◽  
Vol 53 (1) ◽  
pp. 153-168 ◽  
Author(s):  
CLAUDIA R. ALCÁNTARA
Keyword(s):  
Moduli Space ◽  
Invariant Theory ◽  
Geometric Invariant Theory ◽  
Del Pezzo Surfaces ◽  
Holomorphic Foliations ◽  
Geometric Invariant ◽  
Linear Action ◽  
Unstable Foliation ◽  
Rational Fibration ◽  
Del Pezzo

AbstractLet 2 be the space of the holomorphic foliations on ℂℙ2 of degree 2. In this paper we study the linear action PGL(3, ℂ) × 2 → 2 given by gX = DgX ^(g−1) in the sense of the Geometric Invariant Theory. We obtain a characterisation of unstable and stable foliations according to properties of singular points and existence of invariant lines. We also prove that if X is an unstable foliation of degree 2, then X is transversal with respect to a rational fibration. Finally we prove that the geometric quotient of non-degenerate foliations without invariant lines is the moduli space of polarised del Pezzo surfaces of degree 2.

scholarly journals Semi-continuity of stability for sheaves and variation of Gieseker moduli spaces

2019 ◽  
Vol 2019 (749) ◽  
pp. 227-265 ◽  
Author(s):  
Daniel Greb ◽  
Julius Ross ◽  
Matei Toma
Keyword(s):  
Finite Number ◽  
Moduli Spaces ◽  
Stability Condition ◽  
Invariant Theory ◽  
Geometric Invariant Theory ◽  
Stability Conditions ◽  
Geometric Invariant ◽  
Moduli Spaces Of Sheaves ◽  
Stable Sheaves ◽  
The Stability

Abstract We investigate a semi-continuity property for stability conditions for sheaves that is important for the problem of variation of the moduli spaces as the stability condition changes. We place this in the context of a notion of stability previously considered by the authors, called multi-Gieseker-stability, that generalises the classical notion of Gieseker-stability to allow for several polarisations. As such we are able to prove that on smooth threefolds certain moduli spaces of Gieseker-stable sheaves are related by a finite number of Thaddeus-flips (that is flips arising for Variation of Geometric Invariant Theory) whose intermediate spaces are themselves moduli spaces of sheaves.

scholarly journals NOTES ON COHERENT SYSTEMS

2020 ◽  
Vol 28 (1) ◽  
pp. 1-38
Author(s):  
ALEXANDER H.W. SCHMITT
Keyword(s):  
Moduli Spaces ◽  
Invariant Theory ◽  
Vector Bundles ◽  
Geometric Invariant Theory ◽  
Geometric Invariant ◽  
Coherent Systems ◽  
Alternative Approach

We present an alternative approach to semistability and moduli spaces for coherent systems associated with decorated vector bundles. In this approach, it seems possible to construct a Hitchin map. We relate some examples to classical problems from geometric invariant theory.

Sign in / Sign up

Export Citation Format

Share Document