Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options answers only not deleted user 9871

Complex geometry is the study of complex manifolds, complex algebraic varieties, complex analytic spaces, and, by extension, of almost complex structures. It is a part of differential geometry, algebraic geometry and analytic geometry.

6 votes
Accepted

Parameterization of complex analytic subvarieties

The answer to your question is yes, even in a much broader setting and moreover the parametrizing open set can be chosen always to be the unit polydisc! Theorem. (Fornaess-Stout '77). If $X$ is an $n …
diverietti's user avatar
  • 7,902
3 votes

Siu decomposition

I am not sure if I understand correctly your question, but anyway I'll try to answer: the point is that Siu's decomposition is in fact unique, but let me explain better. Let $X$ be a complex manifold …
diverietti's user avatar
  • 7,902
11 votes

Bott Chern cohomology via currents

When $X$ is a compact complex manifold, its Bott-Chern cohomology groups can be computed either by smooth forms or by currents. The proof of this fact can be found for instance in Demailly's book (lin …
diverietti's user avatar
  • 7,902
2 votes
Accepted

Decomposition of hermitian form used in the definition of Griffiths/Nakano positivity

With your notations, the hermitian form $\theta_E$ on $T_X\otimes E$ defined by $\Theta_E$ is given in a somewhat more extrinsic way by $$ \theta_E(v\otimes\sigma,v\otimes\sigma):=h(\Theta_E(v,\bar v) …
diverietti's user avatar
  • 7,902
2 votes
Accepted

Local expression involved in the definition of positivity of vector bundles

My answer will consist mainly of a collection of trivial facts but which nonetheless often generate some confusion. I begin by fixing some notation. Let $V$ be a complex vector space of complex dimen …
diverietti's user avatar
  • 7,902
9 votes
Accepted

Negative holomorphic sectional curvature

Here is the answer. Let $(X,\omega)$ be a Kähler $n$-dimensional manifold. Fix a point $x_0\in X$ an choose local holomorphic coordinates $(z_1,\dots,z_n)$ centered at $x_0$ and such that $(\partial/ …
diverietti's user avatar
  • 7,902
11 votes

Algebraic Geometry versus Complex Geometry

Concerning your example, there is definitely no analytic proof of the existence of rational curves on Fano manifolds. This is one of the dream of complex geometers... You can also consider this weaker …
2 votes

Uniformity of ampleness

1. Here is an elementary and constructive proof from a hermitian point of view. I will reproduce it only in the case of curves and blow-up equal to the identity, the general case being just more comp …
diverietti's user avatar
  • 7,902
3 votes
Accepted

The asymptotic growth of global sections of powers of a complex line bundle

Hi, An enlightening and very elementary proof of this fact can be found in the very complete book of X. Ma and G. Marinescu "Holomorphic Morse inequalities and Bergman kernels". You will find this i …
diverietti's user avatar
  • 7,902
15 votes

Specific line bundle over complex manifold implies Kähler?

As Dima said, it is much more: in fact it is projective. But let me give you some more insights on this kind of questions. I shall give you the definition of four different classes of compact comple …
diverietti's user avatar
  • 7,902
5 votes
Accepted

A big line bundle in complex compact manifold

At least in the projective setting the following holds true (this is taken from J. Kollár "Shafarevich maps and automorphic forms", Proposition 13.14.2). Proposition. Let $X$ be a smooth projective va …
diverietti's user avatar
  • 7,902
1 vote
Accepted

extending biholomorphic maps to bimeromorphic maps

The answer is no. Please check this question I asked some time ago.
diverietti's user avatar
  • 7,902
5 votes

Why Calabi-Yau manifolds should be complex?

I think that one possible answer is that a Calabi-Yau manifold is a Riemannian manifold $M$ with $SU(n)$ Riemannian holonomy, where $2n=\dim_\mathbb R M$. Such a manifold is then necessarily complex, …
diverietti's user avatar
  • 7,902
9 votes

Kähler metric on projectivised bundle

Let me recall you briefly how to obtain such a Kähler metric on the total space of the projectivized bundle. Start with any given hermitian metric $h$ on $E$ and consider on the projectivized bundle …
diverietti's user avatar
  • 7,902
6 votes

Examples of Brody hyperbolic affine varieties which are not Kobayashi hyperbolic

Here is an answer to the second part of the first question. It has been communicated to me by Leandro Arosio. The answer is: yes, there does exist a Stein manifold which is Brody hyperbolic but not K …
diverietti's user avatar
  • 7,902

15 30 50 per page