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Related papers: On Kodaira dimension of almost complex 4-dimension…

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We compute almost-complex invariants $h^{p,0}_{\overline\partial}$, $h^{p,0}_{\text{Dol}}$ and almost-Hermitian invariants $h^{p,0}_{\bar\delta}$ on families of almost-K\"ahler and almost-Hermitian $6$-dimensional solvmanifolds. Finally, as…

Differential Geometry · Mathematics 2021-09-21 Nicoletta Tardini , Adriano Tomassini

A general theorem on the existence of natural torsion-free affine connections on a complete family of compact complex submanifolds in a complex manifold is proved. Applications to twistor theory are discussed.

dg-ga · Mathematics 2008-02-03 Sergey A. Merkulov

We classify four-dimensional compact solvmanifolds up to diffeomorphism, while determining which of them have complex analytic structures. In particular, we shall see that a four-dimensional compact solvmanifold S can be written, up to…

Complex Variables · Mathematics 2007-05-23 Keizo Hasegawa

In this note, we verify that the complex Kodaira dimension $\kappa^h$ equals the symplectic Kodaira dimension $\kappa^s$ for smooth 4-manifolds with complex and symplectic structures. We also calculate the Kodaira dimension for many…

Symplectic Geometry · Mathematics 2010-08-27 Josef G Dorfmeister , Weiyi Zhang

Modulo trivial exceptions, we show that smoothly nontrivial symplectic sums of symplectic 4-manifolds along surfaces of positive genus are never rational or ruled, and we enumerate each case in which they have Kodaira dimension zero (i.e.,…

Symplectic Geometry · Mathematics 2014-10-01 Michael Usher

A $p$-K\"ahler structure on a complex manifold of complex dimension $n$ is given by a $d$-closed transverse real $(p,p)$-form. In the paper we study the existence of $p$-K\"ahler structures on compact quotients of simply connected Lie…

Differential Geometry · Mathematics 2024-04-04 Anna Fino , Asia Mainenti

I propose a few increasingly stronger "superadditivity" conjectures regarding the behavior of Kodaira dimension under morphisms of smooth quasi-projective complex varieties.

Algebraic Geometry · Mathematics 2022-10-14 Mihnea Popa

We introduce an axiomatic definition for the Kodaira dimension and classify Thurston geometries in dimensions $\leq 5$ in terms of this Kodaira dimension. We show that the Kodaira dimension is monotone with respect to the partial order…

Geometric Topology · Mathematics 2022-05-31 Christoforos Neofytidis , Weiyi Zhang

We develop computational techniques which allow us to calculate the Kodaira dimension as well as the dimension of spaces of Dolbeault harmonic forms for left-invariant almost complex structures on the generalised Kodaira-Thurston manifolds.

Differential Geometry · Mathematics 2023-10-16 Tom Holt , Riccardo Piovani

We study the question of integrability of a compatible almost complex structure on a compact symplectic 4-manifold, under various natural assumptions on the curvature of the associated almost Kahler metric.

Differential Geometry · Mathematics 2007-05-23 Vestislav Apostolov , Tedi Draghici

In this paper, we calculate the dimension of the $J$-anti-invariant cohomology subgroup $H_J^-$ on $\mathbb{T}^4$. Inspired by the concrete example, $\mathbb{T}^4$, we get that: On a closed symplectic $4$-dimensional manifold $(M, \omega)$,…

Symplectic Geometry · Mathematics 2016-11-15 Qiang Tan , Hongyu Wang , Jiuru Zhou

In this paper we describe the construction of a new class of non-K\"ahler compact complex manifolds. They can be seen as a generalization of Sankaran, OT and LVMB manifolds. Moreover, we give properties of these new spaces. Their Kodaira…

Complex Variables · Mathematics 2015-10-08 Laurent Battisti , Karl Oeljeklaus

We give a bimeromorphic classification of compact K\"ahler manifolds of Kodaira codimension one that admit a holomorphic one form without zeros.

Complex Variables · Mathematics 2025-12-10 Simon Pietig

We classify flat strict nearly K\"ahler manifolds with (necessarily) indefinite metric. Any such manifold is locally the product of a flat pseudo-K\"ahler factor of maximal dimension and a strict flat nearly K\"ahler manifold of split…

Differential Geometry · Mathematics 2007-05-23 Vicente Cortés , Lars Schäfer

We investigate the integrability of almost complex structures on the twistor space of an almost quaternionic manifold constructed with the help of a quaternionic connection. We show that if there is an integrable structure it is independent…

Differential Geometry · Mathematics 2007-05-23 Stefan Ivanov , Ivan Minchev , Simeon Zamkovoy

Two conjectures relating the Kodaira dimension of a smooth projective variety and existence of number of nowhere vanishing 1-forms on the variety are proposed and verified in dimension 3.

Algebraic Geometry · Mathematics 2007-05-23 Tie Luo , Qi Zhang

Non-split almost complex supermanifolds and non-split Riemannian supermanifolds are studied. The first obstacle for a splitting is parametrized by group orbits on an infinite dimensional vector space. Further it is shown that non-split…

Differential Geometry · Mathematics 2015-01-29 Matthias Kalus

We complete the classification of six-dimensional strongly unimodular almost nilpotent Lie algebras admitting complex structures. For several cases we describe the space of complex structures up to isomorphism. As a consequence we determine…

Differential Geometry · Mathematics 2023-06-19 Anna Fino , Fabio Paradiso

In this paper we introduce the notion of relative Kodaira dimension for a symplectic 4-manifold M with a possibly disconnected embedded symplectic surface F. One notable feature is that the sphere components of F have to be discarded, which…

Symplectic Geometry · Mathematics 2009-04-29 Tian-Jun Li , Weiyi Zhang

We establish a new criterion for a compatible almost complex structure on a symplectic four-manifold to be integrable and hence K\"ahler. Our main theorem shows that the existence of three linearly independent closed J-anti-invariant…

Differential Geometry · Mathematics 2015-09-04 Mehdi Lejmi , Markus Upmeier