Compactify quasi-Kaehler metrics with CR boundaries.
problem Compactify quasi-Kaehler metrics with CR boundaries.
method Introduce almost c--projective geometry and use it to define compactification.
result Compactify quasi-Kaehler metrics and show non-zero scalar curvature on boundary.
Study of quasi-Kähler metrics on complex manifolds linked to c-projective metrizability.
problem Characterizing quasi-Kähler metrics on almost complex manifolds.
method Analyzing the c-projectively invariant metrizability equation and its solutions.
result New geometries induced by non-degenerate solutions with non-vanishing scalar curvature.
C-projective structures are analogues of projective structures in the complex setting. The maximal dimension of the Lie algebra of c-projective symmetries of a complex connection on an almost complex manifold of C-dimension n>1 is classically known to be 2n2+4n. We prove that the submaximal dimension is equal to $…
Derives local forms for Bochner-flat (pseudo-)Kähler metrics.
problem Local description of Bochner-flat metrics.
method Local normal forms for c-projectively equivalent metrics.
result Local description of weakly Bochner-flat metrics.
Researchers compute c-projective symmetry algebras for Kähler surfaces.
problem Understanding symmetries in Kähler surfaces.
method Defined and analyzed c-projective vector fields and computed their symmetries.
result Computed c-projective symmetry algebras for Kähler surfaces with essential c-projective vector fields.
Develops c-projective geometry on complex manifolds.
problem Understanding c-projective structures on Kaehler manifolds.
method Realizes c-projective geometry as a parabolic geometry and uses Cartan or tractor connections.
result Proves the Yano-Obata conjecture for complete Kaehler manifolds.
Characterizes C-projective vector fields on Randers spaces.
problem Characterizing C-projective vector fields on Randers spaces.
method Using a non-Riemannian quantity ${fΞ}$, it is shown that ${fΞ}$ is invariant for C-projective vector fields and the dimension of the algebra of C-projective vector fields is at most n(n+2). result An n-dimensional Randers space has a C-projective algebra of maximum dimension n(n+2) if and only if it is locally Minkowskian or (up to re-scaling) locally isometric to the generalized Funk metric. A vector field on a Kähler manifold is called c-projective if its flow preserves the J-planar curves. We give a complete local classification of Kähler real 4-dimensional manifolds that admit an essential c-projective vector field. An important technical step is a local description of 4-dimensional c-projectively equiv…
We study the local geometry of irreducible parabolic geometries admitting strongly essential flows; these are flows by local automorphisms with higher-order fixed points. We prove several new rigidity results, and recover some old ones for projective and conformal structures, which show that in many cases the existence…
Characterizes projective special complex manifolds using c-projective structures.
problem Characterizing projective special complex manifolds.
method Defining S1-bundles and constructing conical special complex manifolds. result Intrinsic characterization of projective special complex manifolds.
Two Kaehler metrics on one complex manifold are said to be c-projectively equivalent if their J-planar curves, i.e., curves defined by the property that their acceleration is complex proportional to their velocity, coincide. The degree of mobility of a Kaehler metric is the dimension of the space of metrics that are c-…
Study complex quaternionic manifolds and their c-projective structures.
problem Characterize connections on quaternionic manifolds with specific holonomy.
method Quaternionic Feix--Kaledin construction and analysis of c-projective classes.
result Characterize distinguished connections in quaternionic manifolds.
The paper studies symmetries in quaternionic geometry and submanifolds.
problem Understanding symmetries in quaternionic geometry and their implications for submanifolds.
method Generalized Feix--Kaledin construction, infinitesimal symmetries analysis, quaternionic and c-projective symmetries study.
result Conditions for extending c-projective symmetries to quaternionic symmetries and studying specific hyperkähler structures.
Geodesic flows on Kähler manifolds are quantum integrable when metrics are c-projectively equivalent.
problem Quantum integrability of geodesic flows on Kähler manifolds under c-projective equivalence.
method Construction of Poisson-commuting integrals of motion and their quantum counterparts.
result The geodesic flow's integrals of motion commute as quantum operators, leading to separation of variables in Schrödinger's equation.
Two Kähler metrics on a complex manifold are called c-projectively equivalent if their J-planar curves coincide. These curves are defined by the property that the acceleration is complex proportional to the velocity. We give an explicit local description of all pairs of c-projectively equivalent Kähler metrics of arb…
The paper constructs examples of compactifications for Einstein metrics.
problem Compactifying Einstein metrics with specific properties.
method Constructing projective and c--projective compactifications. result Neutral signature Einstein metrics can be compactified canonically.
Study shows complex affine transformations index is at most 2 for Kähler manifolds.
problem Understanding transformations on Kähler manifolds.
method Analyzing groups of transformations on Kähler manifolds.
result Establishes a stronger version of Yano-Obata conjecture for complete Kähler manifolds.
New method finds open subsets with trivial holonomy for certain geometries.
problem Finding open subsets with trivial holonomy for Cartan geometries.
method Analyzing the behavior of isotropies in model geometries to generalize properties of isolated higher-order fixed points.
result Existence of open subsets with trivial holonomy for Cartan geometries with certain isotropies.
The paper studies projectively equivalent para-Kaehler metrics in 4D.
problem Characterizing para-Kaehler metrics with specific properties.
method Developed c-projective geometry for para-Kaehler metrics, focusing on 4D case.
result Local description and characterization of 4D pc-projectively equivalent metrics, including Einstein type.
The mobility of a Kaehler metric is the dimension of the space of metrics with which it is c-projectively equivalent. The mobility is at least two if and only if the Kaehler metric admits a nontrivial hamiltonian 2-form. After summarizing this relationship, we present necessary conditions for a Kaehler metric to have m…
We study Kähler geometry of Bott manifolds and find extremal metrics.
problem Understanding Kähler geometry on Bott manifolds.
method Simple induction and generalized Calabi construction.
result Any stage n Bott manifold admits an extremal Kähler metric.
New metrics defined in Finsler geometry with specific properties.
problem Understanding the properties of Finsler metrics and their subclasses.
method Introducing the generalized Berwald projective Weyl metric and proving properties of the class of generalized Douglas metrics.
result All GDW metrics with vanishing Landsberg curvature are of R-quadratic type. Unified framework for Riemannian, Kähler, and quaternion-Kähler metrics.
problem Unified theories for Riemannian, Kähler, and quaternion-Kähler metrics.
method Projective parabolic geometries and classification of geometries.
result Unified framework generalizing classical theories.
Study projective symmetries in Finsler spaces, showing reductions and constant flag curvature.
problem Exploring projective symmetries in Finsler spaces and their properties.
method Analyzing algebraic sub-algebras and curvature invariants of projective vector fields.
result Closed Finsler spaces with negative Ricci curvature reduce to Killing vector fields.
Abstract: Generalizes supergravity c-map to quaternionic manifolds.
problem Construct quaternionic manifolds from hypercomplex manifolds.
method Construct conical hypercomplex manifolds and associate quaternionic manifolds.
result Quaternionic manifolds can be associated to special complex manifolds.
Extends quaternionic constructions from complex manifolds to more general settings.
problem Construct quaternionic manifolds with circle actions from complex structures.
method Using twistor spaces and connections on line bundles, extend Feix-Kaledin construction.
result Constructs quaternionic manifolds with circle actions, including self-dual conformal 4-manifolds.
Devign uses graph neural networks to identify vulnerabilities efficiently.
problem Challenging and tedious process of identifying vulnerabilities in software systems.
method Devign employs a graph neural network to classify graph-level vulnerabilities using comprehensive code semantic representations.
result Devign significantly outperforms state-of-the-art models in vulnerability identification.
Projective geometry simplifies Sasaki-Einstein structures and their compactification.
problem Understanding and compactifying Sasaki-Einstein structures.
method Projective differential geometry and holonomy reductions.
result Characterization of Sasaki-Einstein structures and their compactification.
Harmonic almost complex structures on specific Lie groups and solvmanifolds identified.
problem Characterizing harmonic almost complex structures on almost abelian Lie groups and solvmanifolds.
method Adapted Gray-Hervella classification to almost abelian Lie groups, characterized harmonic structures.
result Examples of harmonic almost complex structures in different Gray-Hervella classes on compact almost abelian solvmanifolds.
Extends positive and almost positive links to successively almost positive ones.
problem Extending properties of positive and almost positive diagrams and links.
method Introducing successively almost positive diagrams and links, and analyzing their properties.
result Improves known results of positive and almost positive links.
The paper defines and constructs almost complex blow-ups on 4D almost complex manifolds.
problem Existence and uniqueness of almost complex blow-ups on almost complex manifolds.
method Definition and construction of almost complex blow-ups, proving their existence and uniqueness.
result Existence and uniqueness of almost complex blow-ups on 4D almost complex manifolds.
The study examines Riemann solitons and almost solitons on specific Kenmotsu manifolds.
problem Characterizing solitons on Kenmotsu manifolds.
method Analysis of Riemann solitons and gradient almost Riemann solitons on almost Kenmotsu manifolds.
result Construction of examples of Kenmotsu and (κ,μ)′-almost Kenmotsu manifolds. We present a novel certified and complete algorithm to compute arrangements of real planar algebraic curves. It provides a geometric-topological analysis of the decomposition of the plane induced by a finite number of algebraic curves in terms of a cylindrical algebraic decomposition. From a high-level perspective, the…
Classifies slant surfaces in almost para-Hermitian manifolds.
problem Classifying slant surfaces in almost para-Hermitian manifolds.
method Defined slant submanifolds and classified pointwise slant surfaces.
result Classified slant surfaces in four-dimensional almost para-Hermitian manifolds.
Study computes invariants on six-dimensional solvmanifolds, providing symplectic structure obstructions.
problem Computing invariants on six-dimensional solvmanifolds.
method Computed almost-complex and almost-Hermitian invariants on families of solvmanifolds.
result Provides obstructions to symplectic structures on compact almost-complex manifolds.
Conditions for Penrose-Ward transformation on specific manifolds.
problem Conditions for Penrose-Ward transformation on almost G2-manifolds with almost twistorial structures. method Necessary and sufficient conditions derived through Penrose-Ward transformation.
result Conditions for Penrose-Ward transformation on almost G2-manifolds with almost twistorial structures. The study classifies h-almost Ricci-Yamabe solitons in various paracontact manifolds.
problem Classifying h-almost Ricci-Yamabe solitons in paracontact geometry.
method Characterization and classification of para-Kenmotsu, para-Sasakian, and para-cosymplectic manifolds.
result Characterizations and classifications of various paracontact manifolds.
Abstract: Almost Kähler Hodge numbers vary with metric choices.
problem Variation of almost Kähler Hodge numbers with metrics.
method Analysis of almost complex Hodge numbers under different almost Kähler metrics.
result The almost Kähler Hodge number h0,1 varies with metric choices. Study on Hodge theory for almost complex manifolds.
problem Determining Hodge numbers for almost complex manifolds.
method Review and analysis of recent developments in Hodge theory for almost complex manifolds.
result Hodge numbers are almost complex, almost Kähler, or birational invariants in dimension four.
Paper defines almost flat relative bundles and their correspondence with quasi-representations.
problem Understanding the equivalence of topological and smooth almost flatness.
method Introduces almost flatness for relative bundles, proves equivalence, and defines correspondence with quasi-representations.
result Equivalence of topological and smooth almost flatness and construction of almost flat bundles.
Study of almost Yamabe solitons on Kaehler submersions.
problem Characterizing almost Yamabe solitons on Kaehler submersions.
method Analyzing conditions for solitons to be shrinking, steady, or expanding.
result Characterizations for almost Yamabe solitons in terms of extrinsic horizontal scalar curvature.
Study almost rigidity of super Ricci flow with non-negative Muller quantity.
problem Almost rigidity properties of super Ricci flow with non-negative Muller quantity.
method Almost splitting and quantitative stratification theorems established by Bamler for Ricci flow.
result Obtained almost constancy for a certain integral quantity concerning scalar curvature at an almost self-similar point.
Study characterizes Einstein manifolds in almost Ricci solitons.
problem Characterizing Einstein manifolds in almost Ricci solitons.
method Geometric dynamics and geometric analysis methods.
result Characterizes Einstein manifolds in the class of complete almost Ricci solitons.
The paper proves conditions for almost complex manifolds to admit almost complex structures through connected sums.
problem Conditions for almost complex manifolds to admit almost complex structures via connected sums.
method Proving conditions for almost complex manifolds to admit almost complex structures through connected sums of specific manifolds.
result Conditions for the existence of almost complex structures on connected sums of specific manifolds.
Study shows almost complex structures with certain tensor properties are prevalent.
problem Characterizing almost complex structures with specific tensor properties.
method Analyzes the space of almost complex structures on compact manifolds.
result The space of almost complex structures with rank at least k Nijenhuis tensor is either empty or dense in each component.
The study examines almost cosymplectic statistical manifolds and their properties.
problem Characterizing and understanding almost cosymplectic statistical manifolds.
method Analyzing basic properties, proving a characterization theorem, studying curvature, and constructing examples.
result Characterization theorem and corollary for almost cosymplectic statistical manifolds with Kaehler leaves.
The notion of generalized almost paracontact structure on the generalized tangent bundle TM⊕T∗M is introduced and its properties are investigated. The case when the manifold M carries an almost paracontact metric structure is also discussed. Conditions for its transformed under a β- or a B-field transfor…
The paper classifies 3D paracontact and almost paracosymplectic spaces.
problem Classifying 3D paracontact and almost paracosymplectic spaces.
method Detailed structure analysis and local classification for all possible values of κ.
result Local classification of paracontact metric and almost paracosymplectic (κ,μ)-spaces for every possible value of κ.