Photo
Najib Idrissi
Maître de conférences

Université de Paris, Institut de Mathématiques de Jussieu-Paris Rive Gauche

Hello! I am Najib Idrissi. I am a mathematician, and mainly interested in operads and their applications to algebraic topology, more specifically the study of configuration spaces and their links to graph complexes.

I am a maître de conférences at Université Paris Diderot (soon to be merged into Université de Paris). I am part of the team-project Algebraic Topology & Geometry of the Institut de Mathématiques de Jussieu–Paris Rive Gauche. I am one of the organizers of the Topology Seminar of the IMJ-PRG. You can find more info in my CV.

This year, I am involved in the organization of a working seminar on homological stability (in French).

Contact

Research

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Talks

Higher Structures
Jan 23, 2019 • Centre international de rencontres mathématiques (CIRM), Luminy, France
Slides

Configuration spaces and operads
Abstract: Configuration spaces consist of tuples of pairwise distinct points in a given space. Studying the homotopy type of configuration spaces of manifolds is a classical problem in algebraic topology. In this talk, I will explain how to use the theory of operads - more precisely, Kontsevich's proof of the formality of the little disks operads - to obtain results on the real homotopy type of configuration spaces of simply connected closed smooth manifolds. I will also talk about generalizations and applications: manifolds with boundary, framed configuration spaces, factorization homology, and work in progress on complements of submanifolds.

Stockholm Topology Seminar
Dec 11, 2018 • Stockholm University + Royal Institute of Technology (KTH), Stockholm, Sweden
Slides

Configuration spaces and Operads
Abstract: Configuration spaces of manifolds are classical objects in algebraic topology, but studying their homotopy type is a difficult task. In this talk, I will explain how to use ideas coming from the theory of operads (and more precisely Kontsevich's proof of the formality of the little disks operads) to obtain results on the real homotopy type of configuration spaces of compact manifolds. I will also talk about recent applications.

Geometry & Topology Seminar
Nov 8, 2018 • Institut de Mathématiques de Jussieu-Paris Rive Gauche, Paris, France
Slides

Espaces de configuration et Opérades
Abstract: Les espaces de configuration de points sont des objets classiques en topologie algébrique. L'étude de leur type d'homotopie engendre de nombreuses questions et applications dans différents domaines des mathématiques. Dans cet exposé, je présenterai des idées qui viennent de la théorie des opérades et qui permettent d'obtenir des résultats concernant le type d'homotopie rationnel des espaces de configuration de variétés.

Derived Geometry and Higher Categorical Structures in Geometry and Physics (junior speaker)
Jun 20, 2018 • Fields Institute, Toronto, Canada
Slides Video

Curved Koszul duality and factorization homology
Abstract: Koszul duality is a powerful tool that can be used to produce resolutions of algebras in many contexts. In this talk, I explain how to use curved Koszul duality for algebras over unital operads to compute the factorization homology of a closed manifold with values in the algebra of polynomial functions on a standard shifted symplectic space.

…more talks »

Blog

New University of Paris
#job

It’s official: the new University of Paris is born! For the moment, Paris Diderot University still exists, but it will merge with Paris Descartes and the new university on January 1st, 2020; the IPGP will remain a legally separate entity. (Yes, it’s complicated.) We have a new logo that you can view on the university’s twitter account. We also have new statutes that govern the relatively intricate internal structure of the new university. A new website u-paris.fr was announced with great pomp, but it doesn’t work. And most importantly… all the staff got pots and seeds to plant in them! Very symbolic. Hopefully I manage to make it grow correctly.

Digging

I dug up the tiny program I wrote to find minimal surfaces in 2011 for the “grandes écoles” entrance exams. It’s available in the miscellaneous section of my website, along with some pictures. It’s written in OCaml, of course! Ah, memories…

Grant: PEPS JCJC
#grant

I applied in January to a call by the math institute (Insmi) of the CNRS, entitled Projet Exploratoire Premier Soutien « Jeune chercheuse, jeune chercheur » (PEPS JCJC, roughly Exploratory Project, First Support: Young Researcher). These are small grants (3000–6000 €) for young researchers, in order to allow them to travel and/or invite people, and incite them to apply to larger grants in the followings years, such as the ones from the French ANR, or even the ERC (one can dream). I just got the answer: it’s a yes! So my project is now funded in 2019, for the amount of 3500 €. It’s comfortable, especially considering that the application and the administrative requirements are lightweight. Time to get to work!

Higher Structures at the CIRM
#trip

This week I am at the Centre international de rencontres mathématiques (CIRM) in Luminy. I am attending and speaking at the “Higher Structures” conference. The whole event is wonderful! I hope I am not too out of place among the big names in the speakers’ list. I’ve learned a lot of new math during the talks, as well as to speak with people who I hadn’t had the chance to meet yet, or that I am not able to see very often. I’d like to thank Bruno Vallette and all the organizers for giving me this opportunity.

[…] continue reading
Paper accepted in Inventiones!
#paper #conf-spaces

My second paper, The Lambrechts–Stanley Model of Configuration Space, has been accepted for publication in Inventiones Mathematicae! This is a great honor and I am very happy. The refeereing process was a bit above average (14 months for the first report, 7 for the final acceptancee), but I am thankful for it. The anonymous referee had many remarks and questions that greatly improved my paper. Most of the comments were about the presentation of the paper, and thanks to the referee’s suggestions, I believe it has been improved quite a bit. Since I use techniques from several areas of mathematics – algebraic topology, differential geometry, mathematical physics, and of course operad theory – these suggestions helped make the paper more accessible (hopefully) to a broader audience. So, I’d like to thank the referee, as well as many people (see the acknowledgments on my paper): Ricardo Campos, Ivo Dell’Ambrogio, Julien Ducoulombier, Matteo Felder, Benoit Fresse, Ben Knudsen, Pascal Lambrechts, Antoine Touzé, Thomas Willwacher. Anyway, time to celebrate! (And tomorrow’s my birthday 😃)

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