Location: Room 1314, Warren Weaver Hall.

Day and Time: Tuesday, 6:00PM to 7:00PM

(unless stated otherwise).

Day and Time: Tuesday, 6:00PM to 7:00PM

(unless stated otherwise).

For more information please contact
the organizers below.

- 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.

- 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.

- 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.

- 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
**R**^{3}: 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.

- 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).

- 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.

- 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.

- 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.

- 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?

- 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 - 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.

- 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.

- 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

- 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.