Survey on metric behavior of Kähler-Einstein metrics during Calabi-Yau degenerations.
problem Metric behavior of Kähler-Einstein metrics during Calabi-Yau degenerations.
method Survey of recent progress.
result Recent insights into metric behavior during Calabi-Yau degenerations.
Paper solves degenerated circle pattern metric problem in spherical geometry.
problem Existence and rigidity of (degenerated) circle pattern metrics with prescribed total geodesic curvatures.
method Defined prescribed combinatorial Ricci flows and studied their convergence.
result First degenerated result for total geodesic curvatures in spherical background geometry.
Non-Archimedean balanced metrics approximate cscK metrics for totally degenerate abelian varieties
problem Non-Archimedean balanced metrics for polarized abelian varieties
method Non-Archimedean analogue of the cscK metric
result Uniform estimate for Calabi-Yau metrics on fibers
Study metric perturbations to make degenerate harmonic forms non-degenerate.
problem Dealing with degenerate harmonic 1-forms in Riemannian geometry.
method Combining analysis of local expansions with Nash-Moser implicit function theorem.
result Proves deformation to nearby non-degenerate Z/2-harmonic 1-forms.
Study on special metrics on complex manifolds, focusing on degeneracy.
problem Understanding degenerate metrics on complex manifolds.
method Investigation of special-Hermitian metrics, including Kähler and locally conformally Kähler metrics.
result Characterization of degenerate metrics on non-Kähler manifolds.
Study on how Kähler-Einstein metrics behave during degenerations of manifolds.
problem Behavior of Kähler-Einstein metrics during degenerations of manifolds.
method Analysis of collapsing behavior of negative Kähler-Einstein metrics along degenerations of canonical polarized manifolds.
result Kähler-Einstein metrics on fibers collapse to a lower dimensional complete Riemannian manifold in the pointed Gromov-Hausdorff sense.
Study on Calabi-Yau metrics collapsing and complex structure degenerations.
problem Understanding the behavior of Calabi-Yau metrics on degenerating families of manifolds.
method Gluing and singular perturbation techniques, construction of Kähler metrics with torus symmetry.
result Explicit and precise relationships between metric collapsing and complex structure degenerations established in all dimensions.
Study on Calabi-Yau metrics and their degenerations.
problem Understanding degenerations of Ricci-flat Kahler metrics on Calabi-Yau manifolds.
method Survey of recent results on questions about degenerations.
result Survey of recent results on degenerations of metrics.
Study on how incomplete smooth metrics degenerate from asymptotically conical Ricci-flat Kähler metrics.
problem Degeneration of asymptotically conical Ricci-flat Kähler metrics.
method Analysis of Kähler class degeneration and convergence of metrics.
result Construction of singular Calabi-Yau metrics and their metric geometry.
New examples of degenerating metrics on R^4 found.
problem Degenerating Poincaré-Einstein metrics on R^4.
method Riemannian ansatz of Debever and Deimaniański, constructing families.
result Continuous families of metrics with cusps and unexpected degenerations.
Analytic torsion studied for fibred boundary metrics, with applications to conic degeneration.
problem Analytic torsion of fibred boundary metrics and conic degeneration.
method Established invariance and gluing formula for renormalized analytic torsion under deformations of metrics.
result Recovery of a result by Sher and Guillarmou about analytic torsion under conic degeneration.
Sharp diameter bounds for Calabi-Yau degenerations proved.
problem Bounding the diameter of Calabi-Yau metrics during degeneration.
method Sharp upper and lower bounds derived for Ricci-flat Kahler metrics.
result Conjecture confirmed by obtaining precise diameter bounds.
Study higher rank inner products and their tilings to describe tori degenerations.
problem Understanding metric degenerations of tori.
method Introduce higher rank inner products and their tilings, use to describe degenerations.
result Describe metric degenerations of polarized tori and Hausdorff limits of tilings.
Theorem shows generic metrics yield non-degenerate geodesic nets.
problem Characterizing geodesic nets on generic metrics.
method Proving all connected embedded nets are non-degenerate for Baire-generic metrics.
result All stationary geodesic nets are non-degenerate for generic metrics.
New approach to Carrollian geometry using Rimes-bundles.
problem Analyzing Carrollian manifolds with degenerate metrics.
method Principal Rimes-bundles with degenerate metrics and connections. result Canonical non-degenerate metric derived from principal connection.
Study degenerations of Kähler-Einstein metrics on surfaces.
problem Understanding the geometry of Kähler-Einstein metrics on surfaces as they degenerate.
method Construct a Kähler-Einstein neck region to model degeneration.
result Provides a model for the limiting geometry of metrics in the family.
New proof shows certain 4D metrics are non-degenerate if curvature is negative definite.
problem Proving non-degeneracy of Poincaré-Einstein metrics.
method Proved non-degeneracy for 4D metrics satisfying a chiral curvature inequality.
result 4D Poincaré-Einstein metrics are non-degenerate if curvature is negative definite.
We study Yamabe metrics, and the moduli space of Yamabe metrics, on an arbitrary closed 3-manifold M. The main focus is on the boundary behavior of the moduli space, i.e. the behavior of degenerating sequences of unit volume Yamabe metrics on M. It is proved that such degenerations, when non-trivial in a certain sense,…
In this paper we prove that the Kähler-Einstein metrics for a toroidal canonical degeneration family of Kähler manifolds with ample canonical bundles Gromov-Hausdorff converge to the complete Kähler-Einstein metric on the smooth part of the central fiber when the base locus of the degeneration family is empty. We also …
Study on metric bubbles in complex dimensions 1 and 2.
problem Understanding degenerations of Kähler-Einstein metrics.
method Investigation of metric bubble trees for non-collapsing cases.
result Description of a conjectural higher-dimensional picture.
Study on curves minimizing length in a degenerate metric plane.
problem Finding curves minimizing length in a plane with a degenerate metric.
method Established sufficient conditions for existence and non-existence of minimizers, using traveling wave solutions to a bi-stable Hamiltonian system.
result Existence and non-existence of minimizers can occur, with examples provided.
Study on collapsing Calabi-Yau manifolds and their metrics.
problem Understanding degenerations of Calabi-Yau manifolds with Ricci-flat Kahler metrics.
method Survey of recent developments, focusing on volume collapsing metrics.
result New insights into the behavior of Calabi-Yau manifolds under volume collapse.
This is a survey of our recent work on degenerations of Ricci-flat Kahler metrics on compact Calabi-Yau manifolds with Kahler classes approaching the boundary of the Kahler cone.
Study singularities of metrics on Hodge bundles and their topological invariants.
problem Understanding the singularities of metrics on Hodge bundles.
method Analyzing degenerations of Calabi-Yau varieties and studying metrics on Hodge and determinant bundles.
result Dominant and subdominant terms in the expansions of metrics are related to topological invariants of singularities.
We provide a complete list of two- and three-component Poisson structures of hydrodynamic type with degenerate metric, and study their homogeneous deformations. In the non-degenerate case any such deformation is trivial, that is, can be obtained via Miura transformation. We demonstrate that in the degenerate case this …
Study Einstein metrics on nilpotent Lie groups, focusing on degenerate centers and degenerate Euclidean subalgebras.
problem Characterize Lorentzian left invariant Einstein metrics on nilpotent Lie groups.
method Analyzing Lie algebras and using double extension process to classify metrics.
result All nilpotent Lie groups up to dimension 5 with Lorentzian Einstein metrics have degenerate center.
The paper adapts metrics to anti-de Sitter structures, characterizing their degeneracies.
problem Characterizing degeneracies of metrics on anti-de Sitter structures.
method Adapting Hitchin component metrics to anti-de Sitter structures.
result Characterized degeneracies of the pressure metric and showed the Loftin metric is nowhere degenerate.
Study non-degenerate anisocurved surfaces in homogeneous 3-manifolds.
problem Compare and study surfaces with opposite Gaussian curvatures under two different metrics.
method Consider surfaces in homogeneous 3-manifolds with two metrics, impose extrinsic curvature conditions, and analyze Gaussian curvature functions.
result Identify and characterize anisocurved surfaces with opposite Gaussian curvatures under both metrics.
We study one parameter degenerations of complex projective manifolds by introducing certain type of Hodge metrics coming from the pluricanonical forms. We show that degenerations with at most canonical singularities are all in the finite distance boundary of moduli spaces. We also propose the converse to be true in the…
Study small eigenvalues on Kähler manifolds degenerating with induced metrics.
problem Analyzing the asymptotic rates of small eigenvalues on degenerate Kähler manifolds.
method Combining Li's uniform Skoda inequality with Monge-Ampère equations.
result Established exact asymptotic rates for small eigenvalues.
Study of 3D degenerate Riemannian manifolds satisfying specific geometric equations.
problem Characterizing 3D degenerate Riemannian manifolds with solutions to a geometric equation.
method Developed a general approach to solve the equation \(
abla df = \psi Rc + \varphi g\), specifying the metric \(g\) under certain conditions.
result Explicitly described the metric \(g\) and potential function \(f\) for various classes of 3D degenerate spaces.
Study calculates curvatures in holomorphic fibrations using degenerate Hermitian forms.
problem Calculating curvatures in holomorphic fibrations with degenerate Hermitian forms.
method Theory of Chern connections and curvature forms for degenerate Hermitian forms on holomorphic vector bundles.
result Positive holomorphic sectional curvature in Grassmannian bundles if the base does.
Study the limit of Calabi-Yau metrics with degenerate skeletons.
problem Understanding the behavior of Calabi-Yau metrics with degenerate skeletons.
method Using polarised degenerations and optimal transport problems.
result Describe the limiting behaviour of the Calabi-Yau potential.
Study small eigenvalues of Riemann surfaces degenerating with Kähler metrics.
problem Determining small eigenvalues of the Laplacian on degenerating Riemann surfaces.
method Combining heat kernel estimates and Quillen metrics to compute asymptotic behavior of eigenvalues.
result Explicit calculation of small eigenvalues as a function of the parameter.
Geodesics in Kähler metrics connect metrics with constant scalar curvature.
problem Deriving geodesics for relatively Kähler metrics on fibrations.
method Deriving geodesic equation, proving uniqueness, convexity of log-norm functional.
result Fibrations with optimal symplectic connections are polystable.
Introduces a new geometric structure for statistical manifolds with degenerate metrics.
problem Degenerate metrics in statistical manifolds affect geometric structures and applications.
method Introduces quasi-Codazzi structure for degenerate metrics and coherent tangent bundles.
result Generalizes geometric structures and relations for statistical models with degenerate metrics.
Study shows Calabi-Yau metrics converge to a specific form under certain conditions.
problem Degeneration of Calabi-Yau metrics and their limits.
method Optimal transport problem and minimisation of Kontorovich functional.
result Limit data of Calabi-Yau metrics can be encoded into a unique minimiser.
This is a short expository note about Calabi-Yau manifolds and degenerations of their Ricci-flat metrics.
We note that the Bogomolny equation for abelian vortices is precisely the condition for invariance of the Hermitian-Einstein equation under a degenerate conformal transformation. This leads to a natural interpretation of vortices as degenerate hermitian metrics that satisfy a certain curvature equation. Using this view…
Study of Calabi-Yau manifold degenerations near complex structure limits.
problem Understanding polarized degenerations of Calabi-Yau manifolds.
method Improvement of metric convergence results on generic regions.
result Metric convergence for collapsing Ricci-flat Kähler metrics on generic regions.
We prove a rigidity of the lightcone in Minkowski space. It is essentially the unique space endowed with a degenerate Riemannian metric, of lightlike type, and supporting an isometric non-proper action of a semi-simple group.
Proves a conjecture for Calabi-Yau manifolds.
problem Maximal degeneration of Calabi-Yau manifolds.
method Valuative independence condition for section ring.
result Metric SYZ conjecture proven.
New finding on K-semistability in optimal degenerations.
problem Understanding K-semistability in optimal degenerations.
method Analyzing K-unstable varieties and their optimal degenerations.
result Optimal degenerations of K-unstable varieties are relatively K-semistable.
Study finite-energy metrics over complex manifold degenerations.
problem Finite-energy metrics on complex manifolds with singularities.
method Investigate spaces of plurisubharmonic metrics with finite-energy conditions.
result Complete and geodesic metric structure on finite-energy metrics space.
In infinite dimensional Heisenberg group, degenerate distances linked to unbounded curvature.
problem Degenerate distances and unbounded curvature in infinite dimensional Heisenberg group.
method Construct left invariant weak Riemannian and sub-Riemannian metrics, adapt sectional curvature definition.
result Degenerate distances coincide with unbounded sectional curvature.
Desingularizes Einstein metrics with A1 singularities in 4D.
problem Desingularizing Einstein metrics with specific singularities.
method Recursive procedure to desingularize Fuchsian singularities.
result Desingularizations of non degenerate Poincaré-Einstein metrics with A1 singularities remain non degenerate.
We study the behaviour of families of Ricci-flat Kahler metrics on a projective Calabi-Yau manifold when the Kahler classes degenerate to the boundary of the ample cone. We prove that if the limit class is big and nef the Ricci-flat metrics converge smoothly on compact sets outside a subvariety to a limit incomplete Ri…
This paper classifies CSI Kundt metrics related to locally homogeneous degenerate Kundt metrics.
problem Classifying CSI Kundt metrics related to locally homogeneous degenerate Kundt metrics.
method Invariant classification of locally homogeneous CSI Kundt spacetimes of alignment type D.
result Any CSI Kundt metric can be constructed from the classified locally homogeneous ones.