bio  website  wwwirma.ustrasbg.fr/… 

location  Strasbourg  
age  38  
visits  member for  3 years, 1 month 
seen  9 hours ago  
stats  profile views  1,695 
I'm working on complex dynamical systems, more specifically on the local/global aspect of singular holomorphic foliations in the complex plane
10h

reviewed  Reject arithmetic progressions with few primes 
Jul 10 
comment 
Two limit cycles which lie on the same leaf
Dear Ali, have you tried to write down an example? Can you mention what you have tried so far? I particularly think about the article by Llibre and Rodriguez «Configurations of limit cycles and planar polynomial vector fields» where you encounter explicit examples of planar polynomial vector fields with prescribed topological configuration of limit cycles. I'm sure you can answer one of the two questions you raise here by following the work in the article. But you must mention the effort you provided with respect to your problem! 
Jun 26 
reviewed  Approve A delicate elementary inequality 
Jun 22 
comment 
Two vector fields are cojugate but not take orbits
Looks like homework to me... 
Jun 20 
reviewed  Approve Reference request: Intrinsic definition of the strong Whitney topology on $\mathcal{C}^{\infty}(M,\mathbb{R})$ without using charts or jets 
Jun 19 
comment 
Classification of complex Kronecker foliations
The additive and multiplicative actions are related through the exponential mapping. 
Jun 19 
comment 
Classification of complex Kronecker foliations
Yes, obviously you're right, the torus is the quotient of $\mathbb C^*$. 
Jun 19 
comment 
Classification of complex Kronecker foliations
Anyway, the question I understand here is to describe the set of $\theta$ for which the induced foliations are topologically equivalent, right? 
Jun 19 
comment 
Classification of complex Kronecker foliations
Well… for $n\in\mathbb Z$ you have a diffeomorphism $x\mapsto x\alpha^n$. Similarly the additive $\mathbb Z^2$action is given by $(n,m)\cdot x=x+n+m\tau$, which corresponds to $\tau=i$ in your example. 
Jun 19 
comment 
Classification of complex Kronecker foliations
You have a multiplicative action $x\mapsto x\alpha$ for $\alpha\neq 0$, for instance, and the quotient is a torus if $\alpha$ is not real. Anyway, I understood that you were speaking about translation, but there still is an ambiguity, as the action of $\mathbb Z^2$ on $\mathbb C$ usually depends on a complex nonreal parameter $\tau$.So I take it that $\tau=i$ here. 
Jun 19 
reviewed  No Action Needed Determinant of a Certain PositiveDefinite Block Matrix 
Jun 19 
reviewed  Approve Counterexamples to Kollár's conjecture 
Jun 19 
comment 
Classification of complex Kronecker foliations
Could you please describe what are those "obvious" actions ? I can think of different ones, and don't know which is the one you refer to. 
Jun 19 
reviewed  Approve Counterexamples to Kollár's conjecture 
Jun 16 
reviewed  Approve Borel subsets of Polish groups 
Jun 15 
reviewed  Approve Non meager rectangle 
Jun 13 
comment 
Under what conditions a linear automorphism is an isometry of some norm?
It seems to me that the phenomenon you describe with the matrix $A$ will repeat itself whenever you have a nondiagonalisable endomorphism (over $\mathbb C$). 
Jun 11 
revised 
Can every commutative ring of characteristic $p\in\mathbb P$ be written as the form $R/(p)$ with $R$ being a ring of characteristic $0$?
edited title 
Jun 11 
reviewed  Approve Flatness of a simple ring extension 
Jun 10 
awarded  Nice Answer 