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48 results for SKT structures

Study SKT and Kähler structures on specific Lie algebras.

problem Characterize SKT and Kähler structures on solvable Lie algebras with codimension two nilradical.
method Classify and construct new examples of SKT solvable Lie algebras.
result Provide a classification of SKT Lie algebras in dimension six and extend SKT nilpotent Lie algebras to higher dimensions.

The study of invariant SKT structures on nilmanifolds, focusing on 2-step cases.

problem Existence of invariant SKT structures on complex nilmanifolds.
method Construction of examples and negative answer to the existence of invariant SKT structures on higher-step nilmanifolds.
result Negative result on the existence of invariant SKT structures on kk-step (k>2k>2) complex nilmanifolds.

Proves conjecture about compatible SKT and balanced metrics on compact solvmanifolds.

problem Compact complex manifolds with both SKT and balanced metrics.
method Shear construction and classification of two-step solvable Lie algebras.
result Proves conjecture for compact two-step solvmanifolds with invariant complex structures.

For an almost contact metric manifold NN, we find conditions for which either the total space of an S1S^1-bundle over NN or the Riemannian cone over NN admits a strong Kähler with torsion (SKT) structure. In this way we construct new 6-dimensional SKT manifolds. Moreover, we study the geometric structure induced on …

2009-09-22abs ↗pdf ↗

A strong KT (SKT) manifold consists of a Hermitian structure whose torsion three-form is closed. We classify the invariant SKT structures on four-dimensional solvable Lie groups. The classification includes solutions on groups that do not admit compact four-dimensional quotients. It also shows that there are solvable g…

2009-11-03abs ↗pdf ↗

Locally conformal SKT structures are introduced and studied on Lie groups and their compact quotients.

problem Existence and classification of LCSKT structures on Lie groups and their quotients.
method Introducing LCSKT structures and studying their properties on Lie groups and their quotients.
result Existence of non-trivial LCSKT structures on 6-dimensional nilpotent Lie algebras and almost abelian Lie algebras.

A Hermitian metric on a complex manifold is called strong Kähler with torsion (SKT) if its fundamental 2-form ωω is ˉ\partial \bar \partial-closed. We review some properties of strong KT metrics also in relation with symplectic forms taming complex structures. Starting from a 2n2n-dimensional SKT Lie algebra $\mathfr…

2011-04-08abs ↗pdf ↗

The paper explores SKT, balanced, and generalized Kähler structures on specific Lie groups.

problem Investigating invariant SKT, balanced, and generalized Kähler structures on compact quotients of almost nilpotent Lie groups.
method Characterization and classification of Hermitian almost nilpotent Lie algebras, study of structures under flows, and non-existence results.
result Construction of new compact SKT manifolds and examples of non-split generalized Kähler structures.

Symplectic forms taming complex structures on compact manifolds are strictly related to Hermitian metrics having the fundamental form ˉ\partial \bar \partial -closed, i.e. to strong Kähler with torsion (SKT{\rm SKT}) metrics. It is still an open problem to exhibit a compact example of a complex manifold having a tamed …

2010-02-16abs ↗pdf ↗

Study SKT and CYT manifolds with parallel Bismut torsion.

problem Characterize and construct compact complex manifolds with specific geometric properties.
method Characterization via universal cover, construction using mapping torus, investigation of generalized Kaehler structures.
result Existence of non-Bismut flat examples and characterization of universal covers.

We use tools from generalized complex geometry to develop the theory of SKT (a.k.a. pluriclosed Hermitian) manifolds and more generally manifolds with special holonomy with respect to a metric connection with closed skew-symmetric torsion. We develop Hodge theory on such manifolds showing how the reduction of the holon…

2012-03-02abs ↗pdf ↗

Study geometric formal metrics and Massey products on Kähler manifolds with torsion.

problem Interplay between geometrically-Bott-Chern-formal metrics and SKT metrics on Kähler manifolds.
method Analyzing nilmanifolds and Kähler solvmanifolds, proving conditions for existence of SKT metrics and Massey products.
result Any Kähler solvmanifold is geometrically formal, and explicit constructions of lattices with non-vanishing Massey products.

The paper defines two types of hyperbolicity for complex manifolds and proves related results.

problem Defining and studying hyperbolicity for a broader class of complex manifolds.
method Introducing SKT hyperbolicity and Gauduchon hyperbolicity, proving results using SKT and Gauduchon metrics.
result Every SKT hyperbolic manifold is also Kobayashi/Brody hyperbolic and every Gauduchon hyperbolic manifold is divisorially hyperbolic.

In this note we observe that on a 2-step nilpotent Lie group equipped with a left-invariant SKT structure the (1,1)-part of the Bismut-Ricci form is seminegative definite. As application we give a simplified proof of the non-existence of invariant SKT static metrics on 2-step nilmanifolds and of the existence of a long…

2017-07-27abs ↗pdf ↗

We study the existence of strong Kähler with torsion (SKT) metrics and of symplectic forms taming invariant complex structures JJ on solvmanifolds G/ΓG/Γ providing some negative results for some classes of solvmanifolds. In particular, we show that if either JJ is invariant under the action of a nilpotent complement o…

2013-02-22abs ↗pdf ↗

On a complex manifold an Hermitian metric which is simultaneously SKT and balanced has to be necessarily Kähler. It has been conjectured that if a compact complex manifold (M,J) has an SKT metric and a balanced metric both compatible with J, then (M, J) is necessarily Kähler. We show that the conjecture is true for nil…

2015-06-17abs ↗pdf ↗

We study the existence of three classes of Hermitian metrics on certain types of compact complex manifolds. More precisely, we consider balanced, SKT and astheno-Kähler metrics. We prove that the twistor spaces of compact hyperkähler and negative quaternionic-Kähler manifolds do not admit astheno-Kähler metrics. Then w…

2016-08-24abs ↗pdf ↗

The paper explores spectral sequences of complex manifolds with special metrics.

problem Understanding spectral sequences of compact complex manifolds with special metrics.
method Investigation of Frölicher spectral sequences and special metrics (balanced, SKT, Gauduchon) on manifolds.
result Found compact manifolds where spectral sequences do not degenerate at the second page, providing counterexamples and new families.

An SKT metric is a Hermitian metric on a complex manifold whose fundamental 2-form ωω satisfies $\de\debarω=0$. Streets and Tian introduced in \cite{sttiPlur} a Ricci-type flow that preserves the SKT condition. This flow uses the Ricci form associated to the Bismut connection, the unique Hermitian connection with tota…

2010-09-03abs ↗pdf ↗

We study evolution of (strong Kähler with torsion) SKT structures via the pluriclosed flow on complex nilmanifolds, i.e. on compact quotients of simply connected nilpotent Lie groups by discrete subgroups endowed with an invariant complex structure. Adapting to our case the techniques introduced by Jorge Lauret for stu…

2012-10-17abs ↗pdf ↗

Study of complex structures on specific solvmanifolds, proving existence and non-existence results.

problem Classification and properties of complex structures on six-dimensional solvmanifolds.
method Classification of Lie algebras, analysis of complex structures, study of Hermitian metrics.
result Determination of new balanced solvmanifolds and confirmation of conjectures.

We give a construction of integrable complex structures on the total space of a smooth principal bundle over a complex manifold, with an even dimensional compact Lie group as structure group, under certain conditions. This generalizes the constructions of complex structure on compact Lie groups by Samelson and Wang, an…

2016-03-15abs ↗pdf ↗

The study explores polarized deformations of SKT Calabi-Yau manifolds using Aeppli classes.

problem Understanding polarized deformations of SKT Calabi-Yau manifolds.
method Introducing small deformations polarized by Aeppli classes and investigating their properties.
result Existence of primitive elements in Bott-Chern classes and metrics comparison.

Study balanced Hermitian structures on almost abelian Lie algebras, classifying six-dimensional cases.

problem Classify balanced Hermitian structures on almost abelian Lie algebras.
method Classify six-dimensional almost abelian Lie algebras with balanced structures, investigate flow of balanced metrics and anomaly flow.
result Prove conjecture for compact almost abelian solvmanifolds with left-invariant complex structures.

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 ↗

The equality between the balanced and the Gauduchon cones is discussed in several situations. In particular, it is shown that equality does not hold on many twistor spaces, and it holds on Moishezon manifolds. Moreover, it is proved that a SKT manifold of dimension three on which the balanced cone equals the Gauduchon …

2016-08-31abs ↗pdf ↗

The paper studies deformations of Calabi-Yau manifolds using Gauduchon metrics.

problem Deformations of Calabi-Yau manifolds under co-polarised conditions.
method Analyzes local deformations of Calabi-Yau ˉ\partial\bar{\partial}-manifolds using Gauduchon metrics and constructs a new hphp-HS form.
result Proves the pp-SKT hh-ˉ\partial\bar{\partial}-property is deformation open.

The abstract discusses conjectures about metrics on complex manifolds.

problem The abstract tackles the conjectures about metrics on complex manifolds, specifically balanced, SKT, and LCK.
method The abstract uses complex Hermitian manifolds, closed 1-forms, and conjectures to explore these metrics.
result The abstract verifies a conjecture about the Bott--Chern homology for all known classes of LCK manifolds.

SKT improves EKI for Bayesian inverse problems with non-Gaussian targets.

problem Efficiently solving Bayesian inverse problems with expensive forward models and non-Gaussian posterior distributions.
method Embedding EKI and FAKI within a Bayesian annealing scheme to adapt tpCN sampler.
result Significant improvements in convergence rate compared to standard SMC and pCN.

We use the procedure of reduction of Courant algebroids to reduce strong KT, hyper KT and generalized Kaehler structures on Courant algebroids. This allows us to recover results from the literature as well as explain from a different angle some of the features observed there in. As an example, we prove that the moduli …

2012-03-02abs ↗pdf ↗

Study Hermitian metrics with Bismut connection satisfying Bianchi identity and SKT condition.

problem Characterize Hermitian metrics with Bismut connection satisfying Bianchi identity and SKT condition.
method Analyze SKT condition and Bismut Kähler-like metrics, construct new examples, and study pluriclosed flow.
result Construct new examples of Hermitian manifolds satisfying Bismut Kähler-like condition.

We review some constructions and properties of complex manifolds admitting pluriclosed and balanced metrics. We prove that for a 6-dimensional solvmanifold endowed with an invariant complex structure J having holomorphically trivial canonical bundle the pluriclosed flow has a long time solution for every invariant init…

2015-02-11abs ↗pdf ↗

In this paper, we introduce the notions of pp-Hermitian-symplectic and pp-pluriclosed compact complex manifolds as generalisations for an arbitrary positive integer pp not exceeding the complex dimension of the manifold of the standard notions of Hermitian-symplectic and SKT manifolds that correspond to the case $p=…

2018-09-01abs ↗pdf ↗