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Popa and Schnell show that any holomorphic 1-form on a smooth projective variety of general type has zeros. In this article, we show that a smooth good minimal model has a holomorphic 1-form without zero if and only if it admits an analytic…

Algebraic Geometry · Mathematics 2024-12-18 Feng Hao , Zichang Wang , Lei Zhang

Let $X$ be a smooth affine algebraic variety over the field of complex numbers which is contractible. Then every algebraic $G$-torsor on $X$ is algebraically trivial if $G$ is a semi-simple algebraic group. We also show that if $X$ is a…

Algebraic Geometry · Mathematics 2015-07-28 S. Subramanian

We classify all the $6$-dimensional unimodular Lie algebras $\mathfrak{g}$ admitting a complex structure with non-zero closed $(3,0)$-form. This gives rise to $6$-dimensional compact homogeneous spaces $M=\Gamma\backslash G$, where $\Gamma$…

Differential Geometry · Mathematics 2023-05-05 A. Otal , L. Ugarte

We suggest a general framework for compactifing quasi-projective Lagrangian fibrations of geometric origin by holomorphic symplectic varieties. This framework includes a compactification criterion, which we then apply to various fibrations…

Algebraic Geometry · Mathematics 2025-01-22 Giulia Saccà

The authors give a complete classification of projective threefolds admitting a holomorphic normal projective connection. Moreover, they prove a general structure theorem on complex projective manifolds admitting a holomorphic normal…

Algebraic Geometry · Mathematics 2007-05-23 Priska Jahnke , Ivo Radloff

For a general affine connection with parallel torsion and curvature, we show that a post-Lie algebra structure exists on its space of vector fields, generalizing previous results for flat connections. However, for non-flat connections, the…

Differential Geometry · Mathematics 2024-07-04 Erlend Grong , Hans Z. Munthe-Kaas , Jonatan Stava

Let $X$ be a compact connected Riemann surface and $(V, \phi)$ a holomorphic Lie algebroid on $X$ such that the holomorphic vector bundle $V$ is stable. We give a necessary and sufficient condition on holomorphic vector bundles $E$ on $X$…

Algebraic Geometry · Mathematics 2024-06-25 Indranil Biswas , Pradip Kumar , Anoop Singh

I consider the class of surfaces $X$ over algebraically closed fields with numerical invariants given in the title. In characteristic zero, this class contains fake projective planes which were introduced by David Mumford. I prove that in…

Algebraic Geometry · Mathematics 2025-08-19 Kirti Joshi

We show various properties of smooth projective D-affine varieties. In particular, any smooth projective D-affine variety is algebraically simply connected and its image under a fibration is D-affine. In characteristic zero such D-affine…

Algebraic Geometry · Mathematics 2023-01-31 Adrian Langer

This paper presents a complete classification of left-invariant affine and projective vector fields on five-dimensional simply connected nilpotent Lie groups endowed with Riemannian metrics. Building on the classification of left-invariant…

Differential Geometry · Mathematics 2025-09-18 M. L. Foka , R. P. Nimpa , M. B. N. Djiadeu

We introduce a notion of a connection on a coherent sheaf on a weighted projective line (in the sense of Geigle and Lenzing). Using a theorem of Huebner and Lenzing we show, under a mild hypothesis, that if one considers coherent sheaves…

Algebraic Geometry · Mathematics 2009-04-23 William Crawley-Boevey

A well-known theorem of W. Fischer and H. Grauert states that analytic fiber spaces with all fibers isomorphic to a fixed compact connected complex manifold are locally trivial. Motivated by this result, we show that if $k$ is an…

Algebraic Geometry · Mathematics 2021-08-24 Paweł Poczobut

It is known that a Killing field on a compact pseudo-K\"ahler manifold is necessarily (real) holomorphic, as long as the manifold satisfies some relatively mild additional conditions. We provide two further proofs of this fact and discuss…

Differential Geometry · Mathematics 2025-08-25 Andrzej Derdzinski

We show that the main homological dimensions of the algebra of analytic functionals on a connected complex Lie group, as well as some of its completions, coincide with the dimension of the simply connected solvable factor in the canonical…

Functional Analysis · Mathematics 2025-10-31 Oleg Aristov

Using the theory of cohomology support locus, we give a necessary condition for the Albanese map of a smooth projective surface being a submersion. More precisely, assuming the cohomology support locus of any finite abelian cover of a…

Algebraic Geometry · Mathematics 2017-02-20 Botong Wang

Let $G=H\ltimes K$ denote a semidirect product Lie group with Lie algebra $\mathfrak g=\mathfrak h \oplus \mathfrak k$, where $\mathfrak k$ is an ideal and $\mathfrak h$ is a subalgebra of the same dimension as $\mathfrak k$. There exist…

Differential Geometry · Mathematics 2016-04-29 Giovanni Calvaruso , Gabriela P. Ovando

Let $(M,g)$ be a closed oriented negatively curved surface. A unitary connection on a Hermitian vector bundle over $M$ is said to be transparent if its parallel transport along the closed geodesics of $g$ is the identity. We study the space…

Differential Geometry · Mathematics 2010-05-12 Gabriel P. Paternain

For a conformal manifold we introduce the notion of an ambient connection, an affine connection on an ambient manifold of the conformal manifold, possibly with torsion, and with conditions relating it to the conformal structure. The purpose…

Differential Geometry · Mathematics 2012-08-14 Stuart Armstrong , Thomas Leistner

We give a general structure theorem for affine A 1-fibrations on smooth quasi-projective surfaces. As an application, we show that every smooth A 1-fibered affine surface non-isomorphic to the total space of a line bundle over a smooth…

Algebraic Geometry · Mathematics 2020-03-02 Adrien Dubouloz

We prove that the bounded derived category of coherent sheaves on a smooth projective complex variety reconstructs the isomorphism classes of fibrations onto smooth projective curves of genus $g\geq 2$. Moreover, in dimension at most four,…

Algebraic Geometry · Mathematics 2023-09-14 Luigi Lombardi