Study hyperbolic 2-spheres with cone points, describing spaces for n=3.
problem Characterize the space of hyperbolic 2-spheres with cone points.
method Analyzing the space C(a0,a1,…,an) for n=3 and n=4. result Detailed description of spaces for n=3 and examples for n=4. Study on curves on specific arithmetic quotients of hyperbolic 2-ball.
problem No complex curves of certain genus on these arithmetic quotients.
method Volume estimates and understanding special subvarieties.
result For large discriminants, no complex curves of fixed genus.
New 2D complex hyperbolic structures found on sphere orbibundles.
problem Locally rigid complex hyperbolic structures on sphere orbibundles.
method Constructing families of complex hyperbolic structures on disc orbibundles.
result Examples of non-locally rigid complex hyperbolic structures.
The Siu-Yang conjecture is reviewed for complex 2-manifolds.
problem Determining biholomorphic quotients of complex 2-balls.
method Review and analysis of existing results.
result Negative sectional curvature implies biholomorphic quotients of complex 2-balls.
We describe and study the loci equidistant from finitely many points in the so-called complex hyperbolic geometry, i.e., in the geometry of a holomorphic 2-ball B. In particular, we show that the bisectors (= the loci equidistant from 2 points) containing the (smooth real algebraic) curve equidistant from gi…
Holomorphic curves found in compact quotients of SL(2,C).
problem Existence of holomorphic curves in compact quotients of SL(2,C).
method Proved the existence of a pair (Σ, Γ) with specific properties.
result Affirmative answer to questions raised by Huckleberry and Winkelmann, Ghys.
We prove an equidistribution result for totally geodesic submanifolds in a compact locally symmetric space. In the case of Hermitian locally symmetric spaces, this gives a convergence theorem for currents of integration along totally geodesic subvarieties. As a corollary, we obtain that on a complex surface which is a …
Holomorphic curves found in compact quotients of SL(2,C).
problem Proving the existence of holomorphic curves in compact quotients of SL(2,C).
method Non-Abelian Hodge correspondence, WKB analysis, and Morgan-Shalen compactification.
result Every compact quotient of SL(2,C) contains a holomorphic curve of genus at least two.
In this article we prove first of all the nonexistence of holomorphic submersions other than covering maps between compact quotients of complex unit balls, with a proof that works equally well in a more general equivariant setting. For a non-equidimensional surjective holomorphic map between compact ball quotients, our…
In the current article our primary objects of study are compact complex submanifolds of quotient manifolds of irreducible bounded symmetric domains by torsion free discrete lattices of automorphisms. We are interested in the characterization of the totally geodesic submanifolds among compact splitting complex submanifo…
Symplectic reduction extended to Sasakian manifolds.
problem Extending symplectic reduction to Sasakian manifolds.
method Using a semisimple group action on a Sasakian manifold, identifying the categorical quotient with the moment map zero-set quotient.
result Symplectic reduction can be applied to Sasakian manifolds.
In this paper we study numerical properties of quotients of holomorphic log-tensors.
A new method shows open Riemann surfaces have finite genus.
problem Determining the genus of open Riemann surfaces.
method Introducing a quotient space of forms to determine finite genus.
result Open Riemann surfaces have finite genus and can be embedded in a compact surface.
This paper provides an explicit form for symmetric differentials and their corresponding holomorphic functions.
problem Understanding the correspondence between symmetric differentials and L2 holomorphic functions on quotient spaces. method Explicit description of the correspondence between symmetric differentials and weighted L2-holomorphic functions. result Derivation of several applications based on the explicit form of the correspondence.
The paper proves a structure theorem for compact Kähler manifolds with semi-positive holomorphic sectional curvature.
problem Understanding the fundamental groups of compact Kähler manifolds with specific curvature properties.
method Analyzing foliations and topological properties to prove a locally trivial fibration structure.
result Compact Kähler manifolds with semi-positive holomorphic sectional curvature admit a locally trivial fibration structure.
Decomposes complex manifolds with trivial canonical bundle into homogeneous structures.
problem Decomposing complex manifolds with trivial canonical bundle into homogeneous structures.
method Using MMP and foliation theory, we prove a decomposition theorem and deduce properties of holomorphic geometric structures.
result Holomorphic geometric structures on X are locally homogeneous away from an analytic subset of complex codimension at least two. Study of complex projective manifolds using arithmetic lattices.
problem Holomorphic convexity for toroidal compactifications of ball quotients.
method Show that Albanese mapping on an étale covering space generates jets on the interior.
result Shafarevich conjecture on holomorphic convexity satisfied in dimension 2 for arithmetic lattices.
We introduce Morse-type inequalities for a holomorphic circle action on a holomorphic vector bundle over a compact Kaehler manifold. Our inequalities produce bounds on the multiplicities of weights occurring in the twisted Dolbeault cohomology in terms of the data of the fixed points and of the symplectic reduction. Th…
The paper studies spaces of non-compact real algebraic curves and their uniformisation.
problem Understanding the spaces of non-compact real algebraic curves and their uniformisation.
method Construction of spaces of non-compact real algebraic curves and description of their connected components using Fuchsian groups.
result Any connected component of the spaces of non-compact real algebraic curves is homeomorphic to a quotient of a finite-dimensional real vector space by a discrete group.
Constructs a moment map for maps to balanced manifolds.
problem Understanding maps from complex manifolds to balanced manifolds.
method Constructs a moment map for a specific action of biholomorphisms.
result Lays groundwork for balanced quotients.
Let M be a complex nilmanifold, that is, a compact quotient of a nilpotent Lie group endowed with an invariant complex structure by a discrete lattice. A holomorphic differential on M is a closed, holomorphic 1-form. We show that a(M)≤k, where a(M) is the algebraic dimension a(M) (i.e. the transcendence degre…
Embeds CR manifolds into complex spaces using equivariant actions.
problem Embedding strongly pseudoconvex CR manifolds into complex spaces.
method Equivariant CR maps and quotient maps.
result Universal quotient map property for CR manifolds.
The note confirms a conjecture for specific Lie groups.
problem The conjecture about constant holomorphic sectional curvature in non-Kähler geometry.
method Compact quotients of Lie groups with specific properties.
result The conjecture is confirmed for almost abelian Lie algebras and those with certain abelian ideals.
Study geodesics on ball quotients to find nonvanishing sections.
problem Finding nonvanishing holomorphic sections on ball quotients.
method Analyzing sequences of pluricanonical bundles associated to closed geodesics.
result Obtain asymptotics of holomorphic sections on ball quotients.
Study numerically flat bundles on Fujiki manifolds using algebraic groups.
problem Characterize numerically flat principal bundles on Fujiki manifolds.
method Analyzes holomorphic principal bundles and their quotient structures, proving equivalence of conditions involving numerically flat ad bundles and nef line bundles.
result Establishes equivalence among numerically flat ad bundles, nef line bundles, and degree inequalities for reductions of structure groups.
Kähler submanifolds in Iwasawa manifolds are studied.
problem Characterizing Kähler submanifolds in Iwasawa manifolds.
method Analyzing quotient groups and using complex homogeneity.
result Kähler surfaces in Iwasawa manifolds are either abelian or non-projective isotrivial elliptic.
Let X be a compact connected Riemann surface of genus g, with g≥2, and let OX denote the sheaf of holomorphic functions on X. Fix positive integers r and d and let Q(r,d) be the Quot scheme parametrizing all torsion coherent quotients of OX⊕r of degree …
Study numerically flat bundles on non-Kähler manifolds.
problem Characterize holomorphic vector bundles on non-Kähler manifolds.
method Analyze conditions for numerically flatness and effectiveness.
result Numerically flatness is equivalent to specific stability conditions.
We define geometric zeta functions for locally symmetric spaces as generalizations of the zeta functions of Ruelle and Selberg. As a special value at zero we obtain the Reidemeister torsion of the manifold. For hermitian spaces these zeta functions have as special value the quotient of the holomorphic torsion of Ray an…
The paper confirms conjectures about Stein manifolds formed by quotients of the ball.
problem Characterizing Stein manifolds formed by quotients of the ball.
method Analyzing discrete subgroups of PU(n,1) and their quotients.
result The quotient of the ball by geometrically finite groups is Stein.
Kirwan surjectivity proven for equivariant Dolbeault cohomology.
problem Understanding cohomology of Kähler quotients for Hamiltonian actions.
method Using Cartan-Chern-Weil theory to define and prove a Kirwan map.
result A natural surjective Kirwan map established between equivariant Dolbeault cohomologies.
Study gauge theory of real and quaternionic parabolic bundles over real curves.
problem Examining gauge theoretic aspects of real and quaternionic parabolic bundles over real curves.
method Investigate orbits of connections under gauge groups for fixed real or quaternionic structures.
result Gauge-theoretic quotients of real or quaternionic connections are inside the real points of moduli of holomorphic bundles.
SU(n)-structures derived from Kähler manifolds with torus actions.
problem Understanding SU(n)-structures on quotient spaces.
method Using Kähler manifolds with Hamiltonian actions of tori.
result Symplectic quotients inherit SU(n)-structures under certain conditions.
In this article we study compact Kähler manifolds X admitting non-singular holomorphic vector fields with the aim of extending to this setting the classical birational classification of projective varieties with tangent vector fields. We prove that any such a Kähler manifold X admits an arbitrarily small deformatio…
Defines character varieties for real forms of complex classical groups and proves their properties.
problem Characterizing character varieties for real forms of complex classical groups.
method Proposes and proves properties of GR-character varieties as subsets of GC-character varieties. result Character varieties cover the set of irreducible GC-characters fixed by an anti-holomorphic involution. Study compares Kähler quotients of torus actions under varying moment maps.
problem Comparing Kähler quotients of torus actions under varying moment maps.
method Analyzes the transformation of Kähler quotients as moment maps change, proving bimeromorphic transformations and desingularizations.
result Each nondegenerate singular Kähler quotient has a partial and rational desingularization.
We investigate representations of Kähler groups Γ=π1(X) to a semisimple non-compact Hermitian Lie group G that are deformable to a representation admitting an (anti)-holomorphic equivariant map. Such representations obey a Milnor--Wood inequality similar to those found by Burger--Iozzi and Koziarz--Maubon. Thanks…
An LCK manifold with potential is a compact quotient M of a Kahler manifold X equipped with a positive plurisubharmonic function f, such that the monodromy group acts on X by holomorphic homotheties and maps f to a function proportional to f. It is known that M admits an LCK potential if and only if it can be holomor…
Let Sn(X) be the n-fold symmetric product of a compact connected Riemann surface X of genus g and gonality d. We prove that Sn(X) admits a Kähler structure such that all the holomorphic bisectional curvatures are nonpositive if and only if n<d. Let QX(r,n) be the Quot scheme parametrizin…
The study solves open problems in complex geometry by analyzing bounded domains with finite-volume quotients.
problem Analyzing bounded pseudoconvex domains with finite-volume quotients in complex geometry.
method Using semi-simplicity of automorphism groups and applying results to specific settings.
result The automorphism group of certain domains is discrete, and domains with specific properties are biholomorphic to the unit ball.
Paper proves Chern flat for 3D Hermitian manifolds with zero real bisectional curvature.
problem Understanding constant curvature Hermitian manifolds in higher dimensions.
method Examined Hermitian threefolds with zero real bisectional curvature, proving Chern flatness.
result Compact Hermitian threefolds with zero real bisectional curvature are Chern flat.
Classifies 6D homogeneous spaces with holomorphically trivial canonical bundle.
problem Classifying 6D homogeneous spaces with specific geometric properties.
method Analyzing Lie algebras and homogeneous spaces, studying connections and instantons.
result Compact non-Kähler homogeneous spaces are unique in their solutions to the Hull-Strominger system.
Holomorphic bundles on complex manifolds with boundary are studied, extending results from Donaldson's work.
problem Extending holomorphic structures to complex manifolds with boundary.
method Analyzing formally integrable almost complex structures and their extensions to holomorphic structures.
result Holomorphic structures can be extended to a neighborhood of a strictly pseudoconvex boundary.
New method constructs non-arithmetic hyperbolic orbifolds from complex arithmetic ball quotients.
problem Creating non-arithmetic lattices in projective orthogonal groups.
method Using anti-holomorphic involutions on complex arithmetic ball quotients, gluing fixed loci along geodesic subspaces.
result Explicit calculation of the volume of constructed non-arithmetic orbifolds.
Geometric Invariant Theory applied to Kähler manifolds yields analytic models for vector bundles.
problem Constructing local models for vector bundles on Kähler manifolds.
method Applying Geometric Invariant Theory to Kähler manifolds to construct analytic GIT-quotients.
result Existence of Weil-Petersson forms on parameter spaces for stable vector bundles.
Prove long-time existence of pluriclosed flow on certain fibrations
problem Long-time existence of pluriclosed flow on fibrations
method General theorem on holomorphic submersions
result Long-time existence of pluriclosed flow on nilmanifolds, almost-abelian solvmanifolds, and certain complex surfaces
Holomorphic tensors on Vaisman manifolds are invariant under the Lee field.
problem Characterizing holomorphic tensors on Vaisman manifolds.
method Using the parallelism of the Lee form and properties of the Lee field.
result The Kodaira dimension of Vaisman manifolds is invariant under certain quotients.
No exact G₂-structures on compact Lie group quotients.
problem Existence of exact G₂-structures on compact quotients of Lie groups.
method Analyzing compact quotients of seven-dimensional Lie groups by co-compact discrete subgroups.
result Compact quotients of seven-dimensional Lie groups by co-compact discrete subgroups do not admit exact G₂-structures induced by left-invariant ones.