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Related papers: A ddc-type condition beyond the K\"ahler realm

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We give a sufficient condition for the existence of a holomorphic tubular neighborhood of a compact Riemann surface holomorphically embedded in a non-singular complex surface. Our sufficient condition is described by an arithmetical…

Complex Variables · Mathematics 2024-02-13 Satoshi Ogawa

We prove that any Kaehler manifold admitting a flat complex conformal connection is a Bochner-Kaehler manifold with special scalar distribution and zero geometric constants. Applying the local structural theorem for such manifolds we obtain…

Differential Geometry · Mathematics 2007-06-07 Georgi Ganchev , Vesselka Mihova

We prove that for any $n\geq 4$ there are infinitely many real homotopy types of $2n$-dimensional nilmanifolds admitting generalized complex structures of every type $k$, for $0 \leq k \leq n$. This is in deep contrast to the…

Differential Geometry · Mathematics 2019-09-30 Adela Latorre , Luis Ugarte , Raquel Villacampa

For Cartan geometries admitting automorphisms with isotropies satisfying a particular, loosely dynamical property on their model geometries, we demonstrate the existence of an open subset of the geometry with trivial holonomy. This…

Differential Geometry · Mathematics 2025-04-22 Jacob W. Erickson

The present paper mainly presents, for example, explicit classifications of compact smooth manifolds having non-empty boundaries and simple structures where the dimensions are general. Studies of this type is fundamental and important. They…

General Topology · Mathematics 2021-06-21 Naoki Kitazawa

We establish a parametric extension $h$-principle for overtwisted contact structures on manifolds of all dimensions, which is the direct generalization of the $3$-dimensional result from \cite{Eli89}. It implies, in particular, that any…

Symplectic Geometry · Mathematics 2014-10-14 Matthew Strom Borman , Yakov Eliashberg , Emmy Murphy

We give a necessary condition on a geodesic in a Riemannian manifold that can run in some convex hypersurface. As a corollary we obtain peculiar properties that hold true for every convex set in any generic Riemannian manifold (M,g). For…

Differential Geometry · Mathematics 2022-01-13 Alexander Lytchak , Anton Petrunin

We construct the deformation functor associated to a couple of morphisms of differential graded Lie algebras, and use it to study the infinitesimal deformations of a holomorphic map of compact complex manifolds. In particular, in the case…

Algebraic Geometry · Mathematics 2007-05-23 Donatella Iacono

We obtain a formal obstruction, i.e. a necessary condition for the existence of polarised complex deformations of K\"ahler-Ricci solitons. This obstruction is expressed in terms of the harmonic part of the variation of the complex…

Differential Geometry · Mathematics 2023-10-11 Nefton Pali

In this paper we study the geometry of a certain class of compact dynamical horizons with a time-dependent induced metric in locally rotationally symmetric class II spacetimes. We first obtain a compactness condition for embedded…

General Relativity and Quantum Cosmology · Physics 2021-03-26 Abbas M. Sherif , Peter K. S. Dunsby

We build free, bigraded bidifferential algebra models for the forms on a complex manifold, with respect to a strong notion of quasi-isomorphism and compatible with the conjugation symmetry. This answers a question of Sullivan. The resulting…

Algebraic Topology · Mathematics 2024-11-27 Jonas Stelzig

A projective variety has a large fundamental group if its universal covering has no compact subvarieties. In this paper we investigate whether the property of a variety having a large fundamental groups is stable under K\"{a}hler…

Algebraic Geometry · Mathematics 2007-05-23 B. de Oliveira , L. Katzarkov , M. Ramachandran

We prove an equivalence of categories from formal complex structures with formal holomorphic maps to homotopy algebras over a simple operad with its associated homotopy morphisms. We extend this equivalence to complex manifolds. A complex…

Algebraic Topology · Mathematics 2015-01-19 Joan Millès

We propose that under certain conditions heterotic string compactifications on half-flat and nearly-Kahler manifolds are equivalent. Based on this correspondence we argue that the moduli space of the nearly-Kahler manifolds under discussion…

High Energy Physics - Theory · Physics 2009-11-10 Andrei Micu

The Near Horizon Geometry (NHG) equation with a cosmological constant {\Lambda} is considered on compact 2-dimensional manifolds. It is shown that every solution satisfies the Type D equation at every point of the manifold. A similar result…

General Relativity and Quantum Cosmology · Physics 2018-09-26 Denis Dobkowski-Ryłko , Wojciech Kamiński , Jerzy Lewandowski , Adam Szereszewski

The regular type of a real hyper-surface M in an (almost) complex manifold at some point p is the maximal contact order at p of M with germs of non singular (pseudo) holomorphic disks. The main purpose of this paper is to give two intrinsic…

Differential Geometry · Mathematics 2007-05-23 J. -F. Barraud , E. Mazzilli

This paper is concerned with "nice" compactifications of manifolds. Siebenmann's iconic dissertation characterized open manifolds M^m (m>5) compactifiable by addition of a manifold boundary. His theorem extends easily to cases where M^m is…

Geometric Topology · Mathematics 2018-11-06 Shijie Gu , Craig R. Guilbault

Let D be a bounded strongly pseudoconvex domain in a Stein manifold S and let Y be a complex manifold. We prove that the graph of any continuous map from the closure of D to Y which is holomorphic in D admits a basis of open Stein…

Complex Variables · Mathematics 2008-10-15 Franc Forstneric

The orientability problem in real Gromov-Witten theory is one of the fundamental hurdles to enumerating real curves. In this paper, we describe topological conditions on the target manifold which ensure that the uncompactified moduli spaces…

Symplectic Geometry · Mathematics 2013-11-27 Penka Georgieva , Aleksey Zinger

We formulate the necessary conditions for the integrability of a certain family of Hamiltonian systems defined in the constant curvature two-dimensional spaces. Proposed form of potential can be considered as a counterpart of a homogeneous…

Exactly Solvable and Integrable Systems · Physics 2016-12-23 Andrzej J. Maciejewski , Wojciech Szumiński , Maria Przybylska