Geometry Seminar
Courant Institute of Mathematical Sciences
New York University

Spring 2023
A mix of in person and on Zoom presentations.
See mailing list announcements for Zoom details or contact Boris Aronov.

Tuesday, January 31, 2023, in person at 6pm in WWH1314 (251 Mercer Street) and on Zoom

Joseph O'Rourke, Smith College.
Reshaping Convex Polyhedra.
YouTube video

Tuesday, February 7, 2023, at 2pm on Zoom.

Alex Iosevich, University of Rochester.
Vapnik-Chervonenkis dimension and finite point configurations.
YouTube video

Tuesday, February 14, 2023, at 2pm on Zoom.

Da Wei Zheng, University of Illinois Urbana-Champaign.
Halving by a Thousand Cuts Or Punctures.

Tuesday, March 21, 2023, at 2pm on Zoom.

Eyvindur Ari Palsson, Virginia Tech.
On the Erdős distinct distance problem and its many variants.
YouTube video

Tuesday, March 28, 2023, in person at 6pm in WWH1314 (251 Mercer Street) and on Zoom

Igor Pak, UCLA.
Domes over curves.
YouTube video

Tuesday, April 4, 2023, at 2pm on Zoom.

Konrad Swanepoel, London School of Economics.
Extremal questions about matchstick graphs and penny graphs.
YouTube video

Tuesday, April 11, 2023, in person at 6pm in WWH1314 (251 Mercer Street) and on Zoom

Chris Bishop, Stony Brook University.
Optimal triangulation of polygons.
YouTube video

Tuesday, April 25, 2023, in person at 6pm in WWH1314 (251 Mercer Street) and on Zoom

Orit Raz, Hebrew University and IAS.
Hausdorff-dimension analogue of the Elekes—Rónyai theorem and related problems.
YouTube video

Tuesday, May 2, 2023, at 2pm on Zoom.

Sándor Fekete, TU Braunschweig.
Coordinated Motion Planning: Reconfiguring a Swarm of Robots.
YouTube video

Tuesday, May 9, 2023, in person at 6pm in WWH1314 (251 Mercer Street) and on Zoom

Evanthia Papadopoulou, Università della Svizzera italiana.
Abstract Voronoi-like Graphs and Applications.
YouTube video

Fall 2022 (a mix of in person and on Zoom; see mailing list announcements for Zoom meeting ID)

Tuesday, September 6, 26, 2022, at 2pm on Zoom.

Patrick Schnider, U Copenhagen.
Tukey, Tverberg, and other combinatorial depth measures.
YouTube video

Tuesday, September 13, 2022.

No seminar

Tuesday, September 20, 2022, at 6pm in person in room WWH1314 (251 Mercer Street)

Matthew Kendall, Princeton University.
Quantitative Helly-type theorems via sparse approximation.
YouTube video

Tuesday, September 27, 2022.

No seminar

Tuesday, October 4, 2022.

No seminar

Tuesday, October 11, 2022.

No seminar.

Tuesday, October 18, 2022, at 6pm in person and on Zoom.

Boris Aronov, NYU
Circle-shooting in 3D and other intersection queries.
YouTube video

Tuesday, October 25, 2022, at 2pm on Zoom.

Pankaj K. Agarwal, Duke U.
Deterministic, Near-Linear ε-Approximation Algorithm for Geometric Bipartite Matching.
YouTube video

Tuesday, November 1, 2022, at 2pm on Zoom.

Martin Balko, Charles University, Prague
On Helly numbers of exponential lattices.
YouTube video

Tuesday, November 8, 2022, at 2pm on Zoom.

No seminar

Tuesday, November 15, 2022, at 6pm in person.

János Pach, Rényi Institute, Budapest
Perfection and geometry.
YouTube video

Tuesday, November 22, 2022, at 2pm on Zoom.

Jonathan Passant, University of Bristol.
Polynomially-rich lines or circles in sets with few triangles.
YouTube video

Tuesday, November 29, 2022, at 2pm on Zoom.

Zuzana Patáková, Charles University.
On Radon and fractional Helly theorems.
YouTube video

Tuesday, December 6, 2022, at 2pm on Zoom.

Christiane Schmidt, Linköping University.
k-Transmitter Watchman Routes (and Some Guarding Problems).
YouTube video

Tuesday, December 13 2022, at 6pm in person.

Cosmin Pohoata, Institute for Advanced Study, Princeton.
Convex polytopes from fewer points.
YouTube video

Spring 2022 (on Zoom)

Tuesday, February 1, 2022, at 2pm on Zoom

David Eppstein, UC Irvine.
Finding relevant points for nearest-neighbor classification.
YouTube video

Tuesday, February 15, 2022, at 2pm on Zoom

Audie Warren, RICAM.
Non-linear incidence bounds over finite fields.
YouTube video

Tuesday, March 1, 2022, at 2pm on Zoom

Lena Yuditsky, ULB.
Weak coloring numbers of intersection graphs.

Tuesday, March 15, 2022, at 2pm on Zoom

Dominique Attali, CNRS, GIPSA-lab, Grenoble.
Reconstructing manifolds by weighted l₁-norm minimization.
Abstract in PDF
YouTube video

Tuesday, March 29, 2022, at 2pm on Zoom

Monique Teillaud, INRIA Nancy - Grand Est.
Flipping Geometric Triangulations on Hyperbolic Surfaces.
YouTube video

Tuesday, April 12, 2022, 12:30–16:05 ET (New York time)

(Virtual) Discrete & Computational Geometry Day
in Memory of Eli Goodman and Ricky Pollack
founding editors of D&CG
Organized by Springer, NYU, and CUNY
Zoom link: https://springer.zoom.us/j/6440052748
A shiny flyer
A YouTube playlist of videos of the meeting

Program:
12:30 Welcome & Introduction
12:40 Andreas Holmsen (KAIST): An allowable feast
13:15 Micha Sharir (Tel Aviv University): Polynomial partitioning: The hammer and some (recent algorithmic) nails
13:50 Esther Ezra (Bar Ilan University): Recent developments on intersection searching
14:25 Xavier Goaoc (Loria, Nancy): Some questions on order types
15:00 Andrew Suk (UC San Diego): Unavoidable patterns in simple topological graphs
15:35 Sylvain Cappell (Courant Institute): Mesh matrices of graphs, of simplicial complexes and of matroids and the significance of their eigenvalues

More information and abstracts

Tuesday, May 3, 2022, at 2pm on Zoom

Pablo Soberón, Baruch College/CUNY.
The topology of fair partitions
Feliks Gross award talk.
Zoom link

Tuesday, May 10, 2022, at 2pm on Zoom

Postponed to Fall 2022...
Pankaj K. Agarwal, Duke U.
Deterministic, Near-Linear ε-Approximation Algorithm for Geometric Bipartite Matching.

Fall 2021 (on Zoom)

Tuesday, October 5, 2021, at 2pm on Zoom

Pablo Soberón, Baruch College/CUNY.
Stiefel manifolds and mass partition results.
YouTube video

Tuesday, October 19, 2021, at 2pm on Zoom

Gil Kalai, Reichman University, Hebrew University of Jerusalem, and NYU.
Open problems about convex polytopes.
Introductory video
YouTube video of the talk itself

Tuesday, November 2, 2021, at 2pm on Zoom

Anne Driemel, University of Bonn.
Data structures for proximity searching under the Fréchet distance.
YouTube video

Tuesday, November 16, 2021, at 2pm on Zoom

Mark de Berg, Eindhoven University of Technology.
Geometric separators and their applications.
YouTube video

Tuesday, November 30, 2021, at 2pm on Zoom

Jean Cardinal, Université Libre de Bruxelles.
Algorithms for approximate sparse regression and closest induced flats.
YouTube video

Tuesday, December 14, 2021, at 2pm on Zoom

Abdul Basit, Iowa State University.
Zarankiewicz’s problem for semilinear hypergraphs.
YouTube video

Spring 2021 (on Zoom)

Tuesday, February 2, 2021, at 2pm on Zoom

Mayank Goswami, Queens College, CUNY.
How to stay socially distant: A geometric approach.
YouTube video

Tuesday, February 16, 2021, at 2pm on Zoom

Omrit Filtser, Stony Brook University.
Static and streaming data structures for Fréchet distance queries.
YouTube video of the same talk given at another venue

Tuesday, March 2, 2021, at 2pm on Zoom

Sariel Har-Peled, University of Illinois.
On undecided LP, clustering and active learning.
YouTube video

Tuesday, March 16, 2021, at 2pm on Zoom

Carola Wenk, Tulane University.
Comparing embedded and immersed graphs.
YouTube video
Slides

Tuesday, March 30, 2021, at 2pm on Zoom

Anna Lubiw, University of Waterloo.
The visibility center of a polygon.
YouTube video

Tuesday, April 13, 2021, at 2pm on Zoom

Ileana Streinu, Smith College.
Rigidity, circuits and combinatorial resultants.
YouTube video

Tuesday, April 27, 2021, at 2pm on Zoom

Miodrag Iovanov, University of Iowa.
On combinatorial algebras of multi-complexes.

Tuesday, May 11, 2021, at 2pm on Zoom

Chenxi Wu, UW Madison.
Fibered cone, sphere complexes and geometry of metric graphs.

Fall 2020 (on Zoom)

Tuesday, October 20, 2020, at 2pm on Zoom Xavier Goaoc, Université de Lorraine.

Convex hull of random order types.
YouTube video

Tuesday, November 10, 2020, at 2pm on Zoom Emo Welzl, ETH Zürich.

Triangulation flip graphs of planar point sets.
YouTube video

Tuesday, December 8, 2020, at 2pm on Zoom Erin Wolf Chambers, Saint Louis University.

Computing optimal homotopies
YouTube video

Spring 2020

Tuesday, March 3, 2020, at 6pm in WWH1314 at Courant Institute, Thang Pham, University of Rochester.

Erdős-Falconer distance problem over finite fields.

Tuesday, March 10, 2020, at 6pm in WWH1314 at Courant Institute, Peter Winkler, Dartmouth College.

Cop, robber and Kakeya needle.

March 17, 2020, No seminar.

Further seminar meetings have been postponed due to the pandemic.

POSTPONED Tuesday, April 14, 2020, at 6pm in WWH1314 at Courant Institute, POSTPONED Franz Schuster, TU Wien.

POSTPONED Tuesday, April 21, 2020, at 6pm in WWH1314 at Courant Institute, POSTPONED Andrey Kupavskii, IAS, Princeton.

POSTPONED Tuesday, April 28, 2020, at 6pm in WWH1314 at Courant Institute, POSTPONED Rathish Das, Stony Brook University.

POSTPONED Tuesday, May 5, 2020, at 6pm in WWH1314 at Courant Institute, POSTPONED Laura Silverstein.

Fall 2019

Tuesday, September 3, 2019, at 6pm in WWH1314 at Courant Institute, Mozhgan Mirzaei, UCSD.

Extremal Configurations in Point-Line Arrangements.

Tuesday, September 10, 2019, at 6pm in WWH1314 at Courant Institute, Oliver Roche-Newton, Radon Institute for Computational and Applied Math, Linz, Austria.

Growth, incidence bounds and affine group energy.

Friday, September 27, 2019 at 2pm in Rm 5383 at CUNY Graduate Center, Steven Hoehner, Longwood University, Farmville, Virginia.

Intrinsic and dual volume deviations of convex bodies and polytope.

Friday, October 4, 2019 at 2pm in Rm 5383 at CUNY Graduate Center, Chenxi Wu, Rutgers University.

Kazhdan's theorem for metric graphs.

Friday, October 18, 2019, at 2pm in Rm 5383 at CUNY Graduate Center, Ben Lund, Rutgers University.

k-plane Furstenberg sets over finite fields.

Tuesday, October 22, 2019, at 6pm in WWH1314 at Courant Institute, Bhargav Narayanan, Rutgers University.

Disproportionate division.

Tuesday, October 29, 2019, at 6pm in WWH1314 at Courant Institute, Monika Ludwig, Technische Universität Wien.

Valuations on convex functions.

Tuesday, November 5, 2019, at 6pm in WWH1314 at Courant Institute, Mark Lewko,

Discrete Fourier analysis and incidence geometry.

Friday, November 15, 2019 at 2pm in Rm 5383 at CUNY Graduate Center, Valentina Pepe, Sapienza University of Rome.

Finite Geometries and pseudorandom graphs.

Tuesday, November 26, 2019, at 6pm in WWH1314 at Courant Institute, Alex Cohen, Yale University.

Sylvester-Gallai theory in complex space.

Friday, December 6, 2019 at 2pm in Rm 5383 at CUNY Graduate Center, Quentin Dubroff, Rutgers University.

Ordinary configurations in point-line arrangements.

Friday, December 13, 2019 at 1pm in Rm 5383 at CUNY Graduate Center, Leonid Gurvits, City College/CUNY.

Everything you wanted to know about quantum entanglement but had nobody to ask, including some cool and surprising geometrical results like Gurvits-Barnum ball.

Tuesday, December 17, 2019, at 6pm in WWH1314 at Courant Institute, Kolja Knauer, University of Barcelona.

On tope graphs of (complexes of) oriented matroids.

Spring 2019

January 29, 2019, No seminar.

Tuesday, February 12, 2019, at 6pm in WWH1314 at Courant Institute, Pablo Soberon, Baruch College/CUNY.

Tverberg's theorem and weak epsilon-nets for convex sets.

Friday, February 22, 2019 at 2pm in Rm 4419 at CUNY Graduate Center, Steven Hoehner, Farmingdale State College.

An almost sharp concentration inequality for random polytopes and Dirichlet-Voronoi tiling numbers.

Tuesday, February 26, 2019, at 6pm in WWH1314 at Courant Institute, Chaim Even Zohar, UC Davis.

Random Knots are Knotted.

Friday, March 1, 2019 at 2pm in Rm 4419 at CUNY Graduate Center, József Solymosi, University of British Columbia.

Rigidity of planar arrangements.

Tuesday, March 12, 2019, at 6pm in WWH1314 at Courant Institute, Sam Bardwell-Evans, Boston University.

Reducing the distinct distances problem in R^d to an incidence problem.

Friday, March 22, 2019 at 2pm in Rm 4419 at CUNY Graduate Center, Steven Simon, Bard College, New York.

Regular polygonal Tverberg-type theorems.

Friday, March 29, 2019 at 2pm in Rm 4419 at CUNY Graduate Center, Mayank Goswami, Queens College/CUNY.

Recent Progress on the Dynamic Optimality Conjecture.

Tuesday, April 2, 2019, at 6pm in WWH1314 at Courant Institute, Imre Bárány, Rényi Institute, Budapest and University College London.

Theorems of Carathéodory, Helly, and Tverberg without dimension.

Tuesday, April 9, 2019, at 6pm in WWH1314 at Courant Institute, Jonathan Lenchner, IBM T.J. Watson Research Center.

From Hall’s Marriage Theorem to Boolean Satisfiability and Back.

Friday, April 12, 2019 at 2pm in Rm 4419 at CUNY Graduate Center, Shubhangi Saraf, Rutgers University.

Factors of sparse polynomials.

Tuesday, April 16, 2019, at 6pm in WWH1314 at Courant Institute, Yuval Peled, New York University.

On the threshold for simple connectivity in random 2-complexes.

Tuesday, April 23, 2019, at 6pm in WWH1314 at Courant Institute, Franz Schuster, Vienna University of Technology.

Affine Quermassintegrals and Minkowski Valuations.

Tuesday, April 30, 2019, at 6pm in WWH1314 at Courant Institute, Florian Frick, CMU.

Splitting Loops and Necklaces: Variants of the Square Peg Problem.

Friday, May 3, 2019 at 11:30am at Baruch College (55 Lexington Ave), Room 6-215, Joshua Zahl, University of British Columbia.

Tangencies, Incidences, and Unit Distances.

Friday, May 10, 2019 at 2pm in Rm 4419 at CUNY Graduate Center, Károly Bezdek, University of Calgary.

Gromov's conjecture for uniform contractions revisited.

Fall 2018

Friday, August 31, 2018 at 2pm in CUNY Graduate Center, Rm 4419, Various Speakers,

Introductory organizational meeting.

Friday, September 7, 2018 at 2pm in CUNY Graduate Center, Rm 3309, Yumeng Ou, Baruch College, CUNY.

Recent developments on Falconer's distance set problem.

Friday, September 14, 2018 at 2pm in CUNY Graduate Center, Rm 4419, Sandra Kingan, Brooklyn College/CUNY.

Quasiregular Matroids.

Friday, September 21, 2018 at 2pm in CUNY Graduate Center, Rm 4419, Stephen Kobourov, University of Arizona, Tucson.

Contact Representation of Planar Graphs in 2D and 3D.

Tuesday, September 25, 2018, at 6pm in Courant Institute, WWH1314, Thao Do, MIT.

A general incidence bound in high dimensions.

Friday, October 5, 2018 in CUNY Graduate Center, Rm 4419, Frank de Zeeuw, Baruch College/CUNY.

Ordinary lines in space.

Tuesday, October 16, 2018, at 6pm in Courant Institute, WWH1314, Joseph Malkevitch, York College/CUNY and CUNY Graduate Center (Emeritus).

Convex 3-polytopes whose faces are equilateral or isosceles triangles.

Friday, October 26, 2018, No seminar - Fall Workshop on Computational Geometry at Queens College, Oct 26-27.

Friday, November 2, 2018, at *3.30pm* in CUNY Graduate Center, Rm *3212*, Ben Lund, Princeton University.

POSTPONED Erdős distinct distance problem in finite fields.

Tuesday, November 6, 2018, at 6pm in Courant Institute, WWH1314, Franz Schuster, TU Wien.

“Affine” isoperimetric inequalities in real space forms.

Tuesday, November 13, 2018, at 6pm in Courant Institute, WWH1314, Karoly Bezdek, University of Calgary.

On totally separable translative packings.

Tuesday, November 20, 2018, at 6pm in Courant Institute, WWH1314, Radoslav Fulek, IST, Austria.

Variants of the Strong Hanani–Tutte Theorem on Surfaces.

Friday, November 30, 2018 at 2pm in CUNY Graduate Center, Rm 3309, Shira Zerbib, University of Michigan, Ann Arbor.

Colorful phenomena in discrete geometry and combinatorics via topological methods.

Tuesday, December 4, 2018, at 6pm in Courant Institute, WWH1314, Ben Lund, Princeton University.

Erdős distinct distance problem in finite fields.

Friday, December 14, 2018 in CUNY Graduate Center, Rm 4419, Dan Halperin, Tel-Aviv University.

Minkowski Sums of Polyhedra with Holes.

Thursday, December 27, 4.30pm, Room 4419, CUNY Graduate Center, Günter Rote, Freie Universität Berlin.

Lattice paths with states, and counting geometric objects via production matrices.

Spring 2018

January 23, 2018, No seminar.

February 6, 2018, Joseph Malkevitch, York College (CUNY).

Polyomino and Rectilinear Knot Projections.

February 13, 2018, Esther Ezra, Bar-Ilan University and Georgia Tech.

Constructive Polynomial Partitioning for Lines in R³: Revisiting Depth Cycle Elimination.

March 6, 2018, Greg Aloupis, New York University.

Connectivity of Bichromatic Matchings.

March 13, 2018, Ben Lund, University of Georgia.

Typical lattice zonotopes.

March 20, 2018, Thomas Wannerer, University of Jena.

Riemannian curvature measures.

April 3, 2018, Saugata Basu, Purdue University.

On the number of lines on projective hypersurfaces.

April 10, 2018, Adam Sheffer, Baruch College, CUNY.

Geometric Energies: Between Combinatorial Geometry and Additive Combinatorics.

April 17, 2017, Matthew (Matya) Katz, Ben-Gurion University.

Bounded-angle spanning trees and their applications.

April 24, 2018, Karoly Boroczky, Central European University and Rényi Institute.

The dual Minkowski problem and polytopes.

May 1, 2018, Michael Horton, University of Sydney and NYU.

Approximating (k, l)-center clustering for curves.

Fall 2017

September 5, 2017, No seminar (first day of classes at NYU).

September 12, 2017, Natan Rubin, Ben-Gurion University.

Further Consequences of The Colorful Helly Hypothesis.

September 26, 2017, Konstantinos Tsakalidis, NYU/Tandon (in room WWH312).

Dynamic Orthogonal Range Searching on the RAM, Revisited.

October 10, 2017, J. B. Nation, University of Hawaii.

Constructing finite projective planes.

October 17, 2017, Prosenjit Bose, Carleton University.

Routing in Geometric Graphs.

October 24, 2017, Ben Blum-Smith,

When is a sphere quotient a sphere?.

October 31, 2017, Franz Schuster, TU Vienna.

Affine vs. Euclidean Sobolev inequalities.

November 7, 2017, John Iacono, New York University and Université Libre de Bruxelles.

Inference Dimension.

December 12, 2017, No seminar (Monday classes at NYU).

Spring 2017

February 7, 2017, Joseph Malkevitch, Department of Mathematics, York College (CUNY).

Insights from Euler's polyhedral formula into the structure of 3-polytopes.

February 14, 2017, Su Jia, Stony Brook University.

Approximation Algorithms for Time-Window TSP and Prize Collecting TSP Problems.

February 28, 2017, Jean Cardinal, Université Libre de Bruxelles.

Topological Drawings of Complete Bipartite Graphs.

March 7, 2017, Tyler Mayer, Stony Brook University.

TSP With Point Locational Uncertainty.

March 14, 2017, No seminar, Spring recess.

March 21, 2017, Abdul Basit, Rutgers University.

Geometric ideas in Sum-Product theory.

March 28, 2017, János Pach, EPFL, Lausanne and Rényi Institute, Budapest.

VC-dimension and Ramsey's problem.

April 4, 2017, Karoly Boroczky, Central European University and Rényi Institute.

Valuations on lattice polytopes.

April 11, 2017, No seminar.

April 18, 2017, Florian Frick, Cornell University.

Geometric transversality.

April 25, 2017, Kira Adaricheva, Hofstra University.

Representation of convex geometries by convex shapes.

May 2, 2017, Katherine St. John, Lehman College (CUNY), New York.

The shape of phylogenetic treespace.

Fall 2016

September 6, 2016, No seminar.

September 20, 2016, Joseph Malkevitch, Department of Mathematics and Computer Science, York College (CUNY).

Geometrical Problems Inspired by Partitions and Compositions.

September 27, 2016, Alon Efrat, University of Arizona, Tucson.

On Network Disconnectivities with Applications.

October 4, 2016, No seminar.

October 11, 2016, No seminar.

October 18, 2016, Megan Owen, Lehman College, CUNY.

Means and convex hulls in tree space.

October 25, 2016, Mark Yagnatinsky,

Placing a Point to Maximize Angles.

November 1, 2016, Orit Raz, Institute for Advanced Studies, Princeton.

Configurations of lines in 3-space and rigidity of planar structures.

November 15, 2016, John Iacono, New York University.

Solving k-SUM using few linear queries using point location.

November 22, 2016, Mayank Goswami, Queens College (CUNY).

Load Balanced Routing using area-preserving maps and medial axis.

December 6, 2016, Charles Wolf, Rutgers University.

On the Number of Ordinary Lines Determined by Sets in Complex Space.

December 13, 2016, No seminar.

Spring 2016

January 26, 2016, Joshua Zahl, MIT.

New bounds on curve tangencies and orthogonalities.

February 2, Karim Adiprasito, Hebrew University/IAS.

From mixed multiplicities to combinatorial geometries to Hodge theory (and log-concavity of the Whitney coefficients).

February 9, 2016, Jiemin Zeng, Stony Brook University.

Exact and Approximation Algorithms for Data Mule Scheduling in a Sensor Network.

February 23, Ben Lund, Rutgers University.

The number of k-flats spanned by a set of points.

March 8, 2016, Seth Cottrell, New York City Technical College (CUNY).

A method for calculating only part of an eigenstate and an application to quantum walks.

March 15, No seminar.

March 22, Jie Gao, Stony Brook University.

Art Gallery Problem, Indoor Localization and Sensor Scheduling.

March 29, 2016, Chris Bishop, Stony Brook University.

True trees.

April 5, 2016, Károly Bezdek, University of Calgary.

Packing and covering convex bodies by cylinders.

April 12, 2016, Pat Morin, Carleton University, Ottowa.

Turán-Type Theorems for Triangles in Convex Point Sets.

April 19, David Kirkpatrick, University of British Columbia, Vancouver.

Minimizing co-location potential for moving points.

April 26, Bernd Sturmfels, UC Berkeley.

Convexity in Tree Spaces.

May 3, 2016, Alexey Ovchinnikov, Queens College (CUNY).

Complexity of elimination for systems of differential equations.

Fall 2015

September 8, 2015, Gaoyong Zhang, NYU Polytechnic School of Engineering.

Cone volume measure of convex bodies.

September 15, 2015, No seminar.

September 22, 2015, No seminar.

September 29, 2015, Steven Simon, Wellesley College.

Topological (Geometric) Combinatorics via finite Fourier analysis.

October 6, 2015, Jon Lenchner, IBM T.J. Watson Research Center.

An Exposition of the Green-Tao Paper “On Sets Defining Few Ordinary Lines”.

October 13, 2015, No seminar.

October 20, 2015, Noga Alon, Tel Aviv University and IAS, Princeton.

Realization of sign matrices in Euclidean spaces.

October 27, 2015, Sylvain Cappell, Courant Institute.

Enumerative Combinatorics of Graphs and Cell Complexes: Theorems of Trent and of Kirchhoff and Reidemeister-Franz Torsion.

November 3, 2015, Simao Herdade, Rutgers University.

Random walk with different directions.

November 10, 2015, Jean Taylor, Courant Institute.

Icosahedral Order in Materials Science and Geometry, Part I: Real materials.

November 17, 2015, Ted Bisztriczky, University of Calgary.

Erdős-Szekeres type theorems for planar convex sets.

November 24, 2015, Gui Citovsky, Stony Brook University.

Conflict-Free Covering.

December 8, 2015, Marjorie Senechal, Smith College.

Icosahedral Order in Materials Science and Geometry, Part II: If not tilings, then what?

Spring 2015

January 6, 2015, Frank Sottile, Texas A&M University, College Station.

Some more geometry in the secondary fan.

CANCELLED (rescheduled for Mar 3) January 27, 2015, Karim Adiprasito, Hebrew University/IAS.

Cubical Pachner moves and the Hauptvermutung for cubulations.

February 3, Christiane Schmidt, Hebrew University, Jerusalem.

Guarding Variants: Continuous 1.5D Terrain Guarding and (Edge) 2-Transmitter Cover.

February 10, 2015, Stefan Langerman, Free University of Brussels.

The Power of Preprocessing: Detecting and constructing intersections between geometric objects.

February 17, 2015, Micha Sharir, Tel-Aviv University/Courant Institute.

The Elekes-Rónyai-Szabó theory and its applications.

February 24, 2015, Radoslav Fulek, Columbia University, New York.

Vertical Visibility among Parallel Polygons in Three Dimensions.

March 3, 2015, CANCELLED Karim Adiprasito, Hebrew University/IAS.

Graph Chordality Via the Weil Lefschetz Map.

March 10, 2014, Ben Lund, Rutgers University, New Brunswick, NJ.

Isosceles trapezoids, perpendicular bisectors, and few distinct distances.

March 24, Elizabeth Chen,

« having a ball » with spherical geometry.

April 7, Saugata Basu, Purdue University, West Lafayette.

On the isotypic decomposition of cohomology modules of symmetric semi-algebraic sets: polynomial bounds on multiplicities.

April 14, 2015, Dan Ismailescu, Hofstra University.

Improved lower bounds for the chromatic number of several small dimensional Euclidean spaces.

April 21, 2015, Jon Lenchner, IBM T.J. Watson Research Center.

Line Segment Visibility with Sidedness Constraints: Theory and Practice.

April 28, Abdul Basit, Rutgers University.

Some connections between measure partitions and polynomial partitioning.

May 5, 2014, William Steiger, Rutgers University.

Some Geometric Partitioning Questions, Answers, Algorithms.

Fall 2014

September 2, Mayank Goswami, Max-Planck Institute for Informatics, Saarbruecken.

Computing Teichmuller maps between polygons.

September 9, Sasho Nikolov, Rutgers University.

Combinatorial discrepancy for boxes via the ellipsoid-infinity norm.

September 16, Esther Ezra, NYU Polytechnic School of Engineering.

Shallow Packings: Revisiting Haussler's Proof.

September 23, Hee-Kap Ahn, POSTECH, Pohang, South Korea.

A Generalization of the Convex Kakeya Problem.

September 30, Noga Alon, Tel-Aviv University, Tel-Aviv, Israel and Institute for Advanced Studies, Princeton.

Geometric constructions of exotic (hyper)graphs.

October 7, Radoslav Fulek, Columbia University, New York.

Clustered planarity testing for trees.

October 21, Chee Yap, Courant Institute, New York University, New York.

Analytic Root Isolation: a complete unconditional Clustering Algorithm.

November 8-9, Discrete and Computational Geometry,

The Goodman-Pollack Fest/Feast.

November 18, Jonathan Lenchner, IBM T.J.Watson Research Center.

Extensions of Golomb’s Tromino Theorem.

November 25, Brittany Therese Fasy, Tulane University.

Measuring Distances Between Road Networks.

December 9, Joseph Mitchell, Stony Brook University, Stony Brook, New York.

Computational Geometry in Air Traffic Management.

Spring 2014

February 4, Radoslav Fulek, Columbia University.

Crossing Numbers and Combinatorial Characterization of Monotone Drawings of K_n.

February 11, Saugata Basu, Purdue University.

Bounding the equivariant Betti numbers and computing the generalized Euler-Poincaré characteristic of symmetric semi-algebraic sets.

February 25, Adam Sheffer, Tel Aviv University.

Counting plane graphs: Perfect matchings, spanning cycles, and Kasteleyn's technique.

March 11, Michael Werman, Department of Computer Science, The Hebrew University of Jerusalem.

Intrinsic Volumes of Random Cubical Complexes.

March 25, Greg Blekherman, Georgia Tech.

Sums of Squares and Varieties of Minimal Degree.

Apr 8, Justin Iwerks, The Spence School.

Tetrahedron Contact Graphs.

April 22, William Gasarch, Dept of Computer Science, Univeristy of Maryland at College Park.

Distinct Volume Subsets.

April 29, Alex Ryba, Queens College.

The Pascal Mysticum.

May 13, Steven Simon, Wellesley College.

G-Ham Sandwich Theorems. CANCELLED

Fall 2013

September 10, Martin Henk, University of Magdeburg, Germany.

Successive Minima Inequalities.

September 24, Mohammad Nikouei, Stevens Institute of Tecnology.

Weyl Groups of Extended Affine Root Systems of Type $A_1$.

October 1, Joe Mitchell, SUNY, Stony Brook.

Geometric TSP with Neighborhoods.

October 8, Noga Alon, Tel Aviv University, Tel Aviv and IAS, Princeton.

Feasible sequences of vectors.

October 15, Boaz Slomka, Tel Aviv University.

Fractional covering numbers with an application to the Levi-Hadwiger problem.

October 22, Natan Rubin, Institut de Mathématiques de Jussieu/FU Berlin.

On Kinetic Delaunay Triangulations; A Near Quadratic Bound for Unit Speed Motions.

October 29, Bill Steiger, Rutgers University.

Geometric Partitioning.

November 5, David Kirkpatrick, University of British Columbia.

An Approximation Algorithm for Multi-Guarding Galleries.

November 12, Esther Ezra, Courant Institute.

A Size Sensitive Discrepancy Bound for Set Systems of Bounded Primal Shatter Dimension.

November 19, Christiane Schmidt, Department of Applied Mathematics and Statistics, Stony Brook University.

Exact Solutions and Bounds for General Art Gallery Problems and an FPTAS for a Variant.

November 26, Bruno Benedetti, Institute of Computer Science, Freie Universität Berlin.

Metric Geometry and the Diameter of Polytopes.

December 17, Marie-Francoise Roy, University of Rennes, France.

Divide and Conquer Roadmaps for Algebraic Sets.