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A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,657 papers · 148 categories

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48 results for complex structures

This note constructs complex structures on specific isoparametric hypersurfaces.

problem Building complex structures on isoparametric hypersurfaces.
method Constructing almost or complex structures on isoparametric hypersurfaces in unit spheres.
result Complex structures on S1imesS7imesS6S^1 imes S^7 imes S^6 and S1imesS3imesS2S^1 imes S^3 imes S^2 are built.

Study on Kodaira dimension of SU(m)-structures on almost complex manifolds.

problem Understanding the Kodaira dimension of almost complex manifolds with SU(m)-structures.
method Introduced almost complex structure of splitting type and associated SU(m)-structure. Provided constructions for non-invariant almost complex structures with specific Kodaira dimensions.
result Found non-invariant almost complex structures with Kodaira dimensions 0 and -∞.

Study transverse Dolbeault cohomology for almost complex structures.

problem Understanding cohomology of transverse structures on manifolds.
method Define transverse Dolbeault cohomology, extend transverse complex structure, introduce involutive limit distribution.
result Cohomology spaces of (p,0) for almost complex structures coincide with transverse Dolbeault cohomology.

The study classifies complex symplectic structures on 4D Lie algebras and constructs hypersymplectic structures.

problem Classifying and constructing complex symplectic structures on 4D Lie algebras.
method Interpreting complex symplectic and pseudo-Kähler structures, developing a method for constructing hypersymplectic structures.
result Obtained an example of a hypersymplectic structure on a 4-step nilmanifold.

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.

In this work we study the existence of invariant almost complex structures on real flag manifolds associated to split real forms of complex simple Lie algebras. We show that, contrary to the complex case where the invariant almost complex structures are well known, some real flag manifolds do not admit such structures.…

2017-08-03abs ↗pdf ↗

The paper explores complex Poisson structures on smooth functions in complex manifolds.

problem Exploring complex Poisson structures on smooth functions in complex manifolds.
method Considering structures of complex Poisson brackets generated by a (1,1)(1,1)-form.
result Examples of complex Poisson structures are provided in $\C^\ast$.

Almost complex structures found on many homotopy complex projective spaces.

problem Finding almost complex structures on homotopy complex projective spaces.
method New proof using Chern classes and homotopy properties.
result Classification of almost complex structures on homotopy CPn\mathbb{C}P^n for 3n63 \leq n \leq 6.

The paper explores pp-Kähler structures on complex manifolds and their properties.

problem Addressing conjectures on specific types of complex manifolds and their structures.
method Analyzing (n2)(n-2)-Kähler nilmanifolds and holomorphically parallelizable nilmanifolds, deriving necessary conditions for smooth curves of pp-Kähler structures, studying cohomology classes, and providing examples.
result Derives necessary conditions for the existence of smooth curves of pp-Kähler structures and provides examples of compact complex manifolds with pp-Kähler structures.

The paper characterizes and examines nilpotent complex structures on stratified Lie algebras.

problem Characterizing and understanding nilpotent complex structures on stratified Lie algebras.
method Introduced a new descending series pj\mathfrak{p}_j to prove a new characterization of nilpotent complex structures and examined whether these structures preserve the strata.
result Found that there exists a JJ-invariant stratification on a step 2 nilpotent Lie algebra with a complex structure.

We introduce and analyze a new geometric structure on topological surfaces generalizing the complex structure. To define this so called higher complex structure we use the punctual Hilbert scheme of the plane. The moduli space of higher complex structures is defined and is shown to be a generalization of the classical …

2018-12-28abs ↗pdf ↗

The paper explores linear generalised complex structures over vector bundles.

problem Understanding holomorphic vector bundles in a generalized geometry context.
method Adapted linear splitting and equivalence to C\mathbb C-multiplication and C\mathbb C-Lie algebroid structure.
result Generalised complex Lie algebroids are expressed as complex conjugated Lie bialgebroids.

This note is concerned in so called harmonic complex structures introduced by the author previously. I will recall some previous results and emphasize the motivation: Provide an attempt to a fundamental problem in geometry--determining the complex structures on an almost complex manifold. I also discuss the almost-Herm…

2015-01-04abs ↗pdf ↗

The paper constructs Levi flat structures using structure sheaves and differential complexes.

problem Global solvability and regularity of Levi flat structures.
method Employing formal integrability and differential complexes, the paper constructs a resolution for the structure sheaf.
result Global exactness and Sobolev regularity of the differential complex for Levi flat structures.

A complex orthogonal (geometric) structure on a complex manifold is a geometric structure locally modelled on a non-degenerate quadric. One of the first examples of such a structure on a compact manifold of dimension three was constructed by Guillot. In this paper, we show that the same manifold carries a family of uni…

2018-09-18abs ↗pdf ↗

The study characterizes real flag manifolds with invariant generalized almost complex structures.

problem Characterizing real flag manifolds with invariant generalized almost complex structures.
method Characterization through invariant BB-transformations and classification of structures.
result No GM2GM_2-maximal real flag manifolds admit integrable invariant generalized almost complex structures.

This paper connects complex hyperkähler structures to Donaldson-Thomas invariants.

problem Describing geometric structures on spaces of stability conditions.
method Introducing Joyce structures and showing their relation to complex hyperkähler structures.
result A Joyce structure on a complex manifold defines a complex hyperkähler structure on its tangent bundle.

New complex structures found on tangent bundles of Lie groups.

problem Finding integrable complex structures on tangent bundles of Lie groups.
method Inspired by Samelson's construction, a left-invariant integrable almost complex structure is defined on the tangent bundle of any compact Lie group.
result Tangent bundles of compact Lie groups admit left-invariant integrable almost complex structures.

Study on biharmonic almost complex structures on compact manifolds.

problem Existence and regularity of biharmonic almost complex structures.
method Analyzes biharmonic almost complex structures on compact almost Hermitian manifolds, focusing on dimension four.
result Existence of energy-minimizing biharmonic almost complex structures for various topologies and homotopy classes.

A complex structure on a subset of S^6 cannot be extended to a global integrable structure.

problem Non-integrability of complex structures on subsets of S^6.
method Proving the non-integrability of extensions of a specific complex structure on a subset of S^6.
result It is impossible to deform a non-integrable structure to an integrable one on S^6 while fixing it on a subset.

New structures allow for self-crossing singularities, leading to new families of stable generalized complex manifolds.

problem Stable generalized complex structures in higher dimensions with self-crossing singularities.
method Extending stable generalized complex structures to include anticanonical sections with normal self-crossings.
result Construction of large families of stable generalized complex manifolds in four dimensions.

Let M=Γ\GM = Γ\backslash G be a nilmanifold endowed with an invariant complex structure. We prove that Kuranishi deformations of abelian complex structures are all invariant complex structures, generalizing a result of C. Maclaughlin, H. Pedersen, Y.S. Poon and S. Salamon for 2-step nilmanifolds. We characterize small def…

2005-06-15abs ↗pdf ↗

Stable generalized complex structures on certain surfaces are constant.

problem Existence of stable generalized complex structures on ruled surfaces.
method Analysis of sphere bundles over surfaces of genus ≥2.
result Stable generalized complex structures on these surfaces are of constant type.

Study of complex structures on Courant algebroids, linking to Poisson structures.

problem Characterizing generalised complex structures on transitive Courant algebroids.
method Analyzing components and integrability equations in a specific splitting.
result Generalised complex structures imply non-degenerate Poisson structures on the base manifold.

Geometric compactification for complex structures on Lie groups.

problem Compactifying moduli stack of complex structures on Lie groups.
method Describes a geometric compactification using CR structures transverse to a real foliation.
result Extra points represent CR structures transverse to a real foliation.

In this paper, we introduce a new concept so called harmonic complex structure by using harmonic theory for vector bundle-valued differential forms. It is a new structure intermediates between complex structure and Kähler structure. From differential geometric viewpoint, it is a natural generalization of Kähler structu…

2010-07-26abs ↗pdf ↗

We show that all 6-dimensional nilmanifolds admit generalized complex structures. This includes the five classes of nilmanifold which admit no known complex or symplectic structure. Furthermore, we classify all 6-dimensional nilmanifolds according to which of the four types of left-invariant generalized complex structu…

2004-04-25abs ↗pdf ↗

New findings on complex structures in nilpotent Lie algebras and pseudo-Kähler geometry.

problem Classifying complex structures on nilpotent Lie algebras.
method Analysis of Lie algebras in dimensions eight and higher, identifying structures with pseudo-Kähler metrics.
result Identification of pseudo-Kähler nilmanifolds with invariant complex structures, providing counterexamples and topological restrictions.

We introduce integrable complex structures on twistor spaces fibered over complex manifolds. We then show, in particular, that the twistor spaces associated with generalized Kahler, SKT and strong HKT manifolds all naturally admit complex structures. Moreover, in the strong HKT case we construct a metric and three comp…

2012-12-17abs ↗pdf ↗

No direct generalized complex structure can be induced from S6\mathbb S^6's nearly Kähler structure.

problem Existence of generalized complex structures on S6\mathbb S^6.
method Defined integrability in terms of the Dorfman bracket and studied S6\mathbb S^6's nearly Kähler structure.
result No generalized complex structure can be induced from S6\mathbb S^6's nearly Kähler structure.

The study provides obstructions and examples for pp-symplectic structures on complex manifolds.

problem Obstructing the existence of pp-symplectic structures on compact complex manifolds.
method Analyzing properties of (p,p)(p,p)-transverse forms and 2p2p-forms.
result Found obstructions and examples of pp-symplectic structures on compact complex manifolds.

We study the geometry of Engel structures, which are 2-plane fields on 4-manifolds satisfying a generic condition, that are compatible with other geometric structures. A complex Engel structure is an Engel 2-plane field on a complex surface for which the 2-planes are complex lines. We solve the equivalence problems for…

2018-05-19abs ↗pdf ↗

Study on Kodaira dimension of specific solvmanifolds without complex structures.

problem Analyzing Kodaira dimension for almost complex 4D solvmanifolds without integrable structures.
method Classification of solvmanifolds and computation of Kodaira dimension for specific structures.
result Showed that Kodaira dimension is not a deformation invariant for some solvmanifolds.

This study explores complex structures on Lie algebras from graph perspectives.

problem Existence and characterization of complex structures on 2-step nilpotent Lie algebras.
method Introducing adapted complex structures and analyzing integrability conditions.
result Characterization of graphs that admit abelian adapted complex structures and unique invariant subgraphs.

The paper explores invariant vs non-invariant complex structures on Lie groups.

problem Understanding complex structures on Lie groups and their properties.
method Analysis of invariant and non-invariant almost complex structures on compact quotients of Lie groups.
result New computations of Kodaira dimension for invariant and non-invariant structures.

We study existence of complex structures on semidirect products $\g \oplus_ρ \v$ where $\g$ is a real Lie algebra and ρρ is a representation of $\g$ on $\v$. Our first examples, the Euclidean algebra $\e(3)$ and the Poincaré algebra $ \e(2,1)$, carry complex structures obtained by deformation of a regular complex stru…

2003-07-29abs ↗pdf ↗