Linked Questions

32 votes
0 answers
6k views

A paper to the question, if the six dimensional sphere is a complex manifold [duplicate]

for a few days a paper was published on arxiv.org with the title "The six dimensional sphere is a complex manifold": http://arxiv.org/PS_cache/math/pdf/0505/0505634v3.pdf Because I am not able to ...
Florian Modler's user avatar
76 votes
2 answers
9k views

Complex structure on $S^6$ gets published in Journ. Math. Phys

A paper by Gabor Etesi was published that purports to solve a major outstanding problem: Complex structure on the six dimensional sphere from a spontaneous symmetry breaking Journ. Math. Phys. 56, ...
Misha Verbitsky's user avatar
23 votes
2 answers
2k views

Is the complex structure of $\mathbb CP^n$ unique?

Let $\mathbb CP^n$ denotes the complex projective space of dimension $n$, we have a standard complex structure of $\mathbb CP^n$, and my question is: is this complex structure unique? Or equivalently, ...
Tom's user avatar
  • 449
52 votes
1 answer
17k views

Atiyah's May 2018 paper on the 6-sphere

A couple years ago Atiyah published a claimed proof that $S^6$ has no complex structure. I've heard murmurs and rumors that there are problems with the argument, but just a couple months ago he ...
Paul Siegel's user avatar
  • 28.9k
8 votes
2 answers
1k views

Does S^6 have the structure of an algebraic variety?

More accurately, the question should be: Is it known that $S^6,$ the 6-dimensional sphere, is $not$ a (proper) complex algebraic variety, or algebraic space? And is there a reference? It's easy to see ...
shenghao's user avatar
  • 4,215
48 votes
0 answers
17k views

What is the current understanding regarding complex structures on the 6-sphere?

In October 2016, Atiyah famously posted a preprint to the arXiv, "The Non-Existent Complex 6-Sphere" containing a very brief proof $S^6$ admits no complex structure, which I immediately read and ...
jdc's user avatar
  • 2,984
50 votes
0 answers
12k views

Atiyah's paper on complex structures on $S^6$

M. Atiyah has posted a preprint on arXiv on the non-existence of complex structure on the sphere $S^6$. https://arxiv.org/abs/1610.09366 It relies on the topological $K$-theory $KR$ and in ...
David C's user avatar
  • 9,832
5 votes
1 answer
1k views

An almost complex structure on the real $n$-sphere $S^n$

If $R\mathrel{:=}\mathbb{R}[x_1,\dotsc,x_{n+1}]/(x_1^2+\dotsb+x_{n+1}^2-1)$ and $S^n\mathrel{:=}\operatorname{Spec}(R)$ is the real $n$-spere, a classical result of Borel and Serre says that the only ...
user avatar
10 votes
0 answers
6k views

Atiyah's paper "Non-existent complex 6-sphere"

I'm trying to understand the main idea of Atiyah's proof (https://arxiv.org/abs/1610.09366). Although there were discussions on MO year ago I couldn't find answers to my questions. Consider the ...
Max Borovkov's user avatar
4 votes
0 answers
303 views

PDE obtained while trying to construct a complex structure

Upon reading this answer to this question, the last paragraph mentions the following. "Requiring the [almost complex] structure to be integrable corresponds to a certain PDE for this map." ...
Paul Cusson's user avatar
  • 1,755