Photo of Nir Gadish

Nir Gadish

Research

Preprints

Infinitesimal calculations in fundamental groups (with A. Ozbek, D. Sinha and B. Walter)
(preprint) ArXiv:2403.20264.
Letter-braiding: a universal bridge between combinatorial group theory and topology
(preprint) ArXiv:2308.13635.
A Serre spectral sequence for the moduli space of tropical curves (with C. Bibby, M. Chan and C. Yun)
(preprint) ArXiv:2307.01960.

Publications

Configuration spaces on a wedge of spheres and Hochschild-Pirashvili homology (with L. Hainaut)
Annales Henri Lebesgue (accepted).
Homology representations of compactified configurations on graphs applied to M2,n (with C. Bibby, M. Chan and C. Yun)
Experimental Mathematics (2023): 1-13.
Product Expansions of q-Character Polynomials (with A. Balachandran, A. Huang and S. Sun)
Journal of Algebraic Combinatorics 57, no. 3 (2023): 975-1005.
Correction to the article A spectral sequence for stratified spaces... (with D. Petersen)
Geometry & Topology 25, no. 5 (2021): 2699-2706.
Deletion and contraction in configuration spaces of graphs. (with S. Agarwal, M. Banks and D. Miyata)
Algebraic & Geometric Topology (2021), DOI:10.2140/agt.2021.21.3663
A generating function approach to new representation stability phenomena in orbit configuration spaces. (with C. Bibby)
Transactions of the AMS, Series B 10, no. 09 (2023): 241-287.
Combinatorics of orbit configuration spaces. (with C. Bibby)
International Mathematics Research Notices, DOI:rnaa296 (2020).
Adding points to configurations in closed balls. (with L. Chen, J. Lanier)
Proceedings of the AMS (2019).
Dimension-independent statistics of GL(n)$ via character polynomials.
Proceedings of the AMS (2019).
An explicit symmetric DGLA model of a bi-gon. (with I Griniasty and R. Lawrence)
Journal of Knot Theory and Its Ramifications Vol 28, No. 11 (2019).
A trace formula for the distribution of rational G-orbits in ramified covers, adapted to representation stability.
New York Journal of Mathematics, Vol. 23 (2017): 987-1011.
Categories of FI type: a unified approach to generalizing representation stability and character polynomials.
Journal of Algebra, Vol. 480 (2017): 450-486.
Representation Stability for Families of Linear Subspace Arrangements.
Advances in Mathematics, Vol. 322 (2017): 341-377.

Not for publication

My Ph.D. thesis, titled: A general framework for representation stability, with applications to arrangements and arithmetic. Thesis Advisor: Prof. Benson Farb.

My topic proposal, on representation stability and applications to arithmetic statistics, under the supervision of Prof. Benson Farb.

My research project for a complex analysis graduate class at the University of Chicago: discussing the Ferrari cubic resolvent as a map between configuration spaces.

My undergraduate thesis, on a free DGLA model for the 2-cell. Thesis Advisor: Prof. Ruth Lawrence.

Talks

Recordings of seminar and conference talks

Between the Bar/Hochschild complex and the fundamental group
(Sep 2024) Topology Seminar, at UPenn
(Lots of) Unstable cohomology of moduli spaces of curves with marked points
(Feb 2023) Topology Seminar, at U. of Minnesota
The "generating function" of orbit configuration spaces
(Apr 2020) Topology Seminar, at Purdue U.
Representation stability for finitely generated arrangements
(Oct 2017) No Boundaries -- Farb 50th birthday conference, at the U. of Chicago

Expository

Height of a formal group as a complete invariant
2021 Apr in the Harvard-MIT Juvitop seminar [virtual]
Intro to spectral sequences
2021 Jan in the Farb and Friends learning seminar (U. of Chicago)
Intro to smooth manifolds
2017 Sep in the WOMP program (U. of Chicago)
Hamiltonian dynamics and Noether's theorem
2016 Nov in the Farb and Friends Student Seminar (U. of Chicago)
Classical mechanics without coordinates
2016 Oct in the student Pizza Seminar (U. of Chicago)
Algebraic number theory and the class group
2016 Sep in the WOMP program (U. of Chicago)
Nonstandard Analysis (limits bad, infinitesimals good)
2016 Apr in the student Pizza Seminar (U. of Chicago)
Destiny, fate and free will - an incomplete guide to forcing and independence in Set theory
2015 Mar in the student Pizza Seminar (U. of Chicago)

Public engagement

What modern mathematicians do
2017 Feb in the Kfar Masaryk community lecture series (Kibbutz Kfar Masaryk, Israel)

Teaching

Notes

Representation theory supplementary material

18.204 (Fall 2020)

Final math communication projects from my (Fall 2020) 18.204 course at MIT - Communication intensive course on discrete mathematics:

Advice for 1st gen students (UNDER CONSTRUCTION!)

There are lots of hidden avenues for success in college, and students coming from non-academic backgrounds often go unaware that they are missing out. I've tried to compile a list of some opportunities that ambitious students should keep in mind. If you can think of others to add to this list, please send me an email!

About me

I am an assistant professor at the University of Pennsylvania. My research interests lie in the interplay between algebraic topology, moduli problems, group theory and representation theory. Recently, I've been most interested in invariants of words in groups and their applications in low dimensional topology. Previously, I worked on representation stability phenomena in configuration spaces and moduli spaces.

Postal address
209 S. 33rd Street
Philadelphia, PA 19104
USA
E-mail ngadish [at] math.upenn.edu
Office 4N24 in David Rittenhouse Laboratory
My CV is found here