Geometric Structures - Noemie Combe - Feb 2 - 4:00 pm (Rome Time)

[Miruna - Stefana Sorea]

Dear All, 

this is to announce the next seminar from the series "Geometric
Structures".

Speaker: NOÉMIE COMBE ( [1]Max Planck Institute for Mathematics in the
Sciences, Leipzig [1]) [1] 

Title:  Complement of the discriminant variety, Gauss-skizze operads and
hidden symmetries

Time: February 2, 2021, 4:00 pm (Rome Time) 

Venue: from remote only, on zoom at this link 
https://sissa-it.zoom.us/j/85675591787?pwd=TUo2VXpmcEhOU1paRzBXUWp2MU1odz09
[2]
Passcode: geometry

Abstract:  

In this talk, the configuration space of marked points on the complex
plane is considered. We investigate a decomposition of this space by
so-called Gauss-skizze i.e. a class of graphs being forests. These
Gauss-skizze, reminiscent of Grothendieck's dessins d'enfant, provide a
totally different real geometric insight on this complex configuration
space, which under the light of classical complex geometry tools,
remains invisible. Topologically speaking, this stratification is shown
to be a Goresky-MacPherson stratification. 

  We prove that for Gauss-skizze, classical tools from deformation
theory, ruled by a Maurer--Cartan equation can be used only locally. 

  We show as well, that the deformation of the Gauss-skizze is governed
by a Hamilton--Jacobi differential equation. 

Finally, a Gauss-skizze operad is introduced which can be seen as an
enriched Fulton--MacPherson operad, topologically equivalent to the
little 2-disc operad. 

The combinatorial flavour of this tool allows not only a new
interpretation of the moduli space of genus 0 curves with n marked
points, but gives a very geometric understanding of the
Grothendieck--Teichmuller group.   
  More information can be found here:
https://sites.google.com/view/geometric-structures/ [3] 

Everyone is welcome! 

-- 
_Miruna-Stefana Sorea_
_Postdoctoral Researcher_
_Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste,
Italy_
_HTTPS://SITES.GOOGLE.COM/VIEW/MIRUNASTEFANASOREA/_ 

Links:
------
[1]
https://www.google.com/url?q=https%3A%2F%2Fnoemie-combe-23.webself.net%2Faccueil&sa=D&sntz=1&usg=AFQjCNFALx1mTIn6gvpy771vHWwwOVjnzg
[2]
https://sissa-it.zoom.us/j/85675591787?pwd=TUo2VXpmcEhOU1paRzBXUWp2MU1odz09
[3] https://sites.google.com/view/geometric-structures/