The combinatorics seminar in Stockholm

Fall 2006 - Spring 2012, A-Z

Download the full seminar archive (2006-2012).
Spring 2012   Fall 2011
Spring 2011   Fall 2010
Spring 2010   Fall 2009
Spring 2009   Fall 2008
Spring 2008   Fall 2007
Spring 2007   Fall 2006

Michał Adamaszek, Dense flag triangulations of 3-spheres and extremal graph theory, Apr 25, 2012
Armen Asratian, On local-global phenomena in hamiltonian graphs, Feb 28, 2007
Christos Athanasiadis, The absolute order on a finite Coxeter group, Apr 20, 2009
Per Austrin, Approximability and unique games, Jan 28, 2009

Jonathan Barmak, Weak, simple and strong homotopy types, Aug 26, 2009
Jonathan Barmak, A finite space approach to the Andrews-Curtis conjecture, Feb 10, 2010
Jonathan Barmak, A new tool to study homotopy invariants of independence complexes, May 12, 2010
Jonathan Barmak, Colorings of a poset, coverings and fundamental groups, May 9, 2012
Bruno Benedetti, Counting manifolds via discrete Morse theory, Sep 8, 2010
Bruno Benedetti, Metric Geometry and Collapsibility, Sep 14, 2011
Alexander Berglund, Golodness of Stanley-Reisner rings, Sep 19, 2007
Louis J. Billera, Flag Enumeration in Polytopes, Eulerian Partially Ordered Sets and Coxeter Groups, June 1, 2011
Michael Björklund (with Alexander Engström), Characterizations of totally nonnegative matrices and a proof of a conjecture of Björner, Feb 14, 2007
Jakob Björnberg, Random Poisson flows on graphs, Mar 28, 2007
Anders Björner, Generalizing the upper and lower bound theorems for simplicial polytopes, Nov 1, 2006
Anders Björner, Connectivity of polytope boundaries and rigidity of posets, Oct 3, 2007
Anders Björner, Random walks on complex hyperplane arrangements, Nov 14, 2007
Anders Björner, Användning av FKG och liknande olikheter i extremal kombinatorik, Dec 10, 2008
Anders Björner, A q-analogue of the FKG inequality and some applications, Sep 2, 2009
Anders Björner, A cell complex in number theory, Feb 24, 2010
Anders Björner, Permutation statistics revisited, Nov 23, 2011
Aart Blokhuis, Do we know all 3-chromatic distance regular graphs?, May 9, 2007
Mats Boij, On the shape of a pure O-sequence, Apr 14, 2010
Petter Brändén, Negative dependence, log-concavity and zeros of polynomials, May 23, 2007
Petter Brändén, The Lee-Yang program and linear operators preserving stability, Feb 13, 2008
Petter Brändén, Infinite log-concavity and zeros of polynomials, Oct 28, 2009
Petter Brändén, Toric arrangements and multivariate arithmetic Tutte polynomials, Feb 8, 2012
Francis Brown, From biomathematics to enumerative combinatorics: genetic microarrays and up-down permutations, Nov 22, 2006
Michelle Bucher-Karlsson, Minimal triangulations of products of polygons, Oct 29, 2008

Dustin Cartwright, Three notions of tropical rank for symmetric matrices, Apr 27, 2011
Ruth Charney, Groups associated to random graphs, Mar 14, 2012
Sunil Chhita, Particle Systems Arising from an Anti-ferromagnetic Ising Model, Oct 26, 2011
Anders Claesson, Conway's napkin problem, Dec 6, 2006
Anders Claesson, Stack sorting, trees and pattern avoidance, Dec 5, 2007
Anders Claesson, (2+2)-free posets, ascent sequences and pattern avoiding permutations, Apr 29, 2009
María Angélica Cueto, Tropical secant graphs of monomial curves, Mar 23, 2011

Sandra Di Rocco, Discriminants and defect polytopes, Feb 21, 2007
Sandra Di Rocco, On a conjecture of Batyrev and Nill, Sep 17, 2008
Persi Diaconis, Shuffling Cards and Hopf Algebras, Feb 15, 2012

Torsten Ekedahl, Shellability of elementary collapses, Nov 12, 2008
Eric Emtander, $d$-flag complexes and chordal hypergraphs, Feb 27, 2008
Alexander Engström, Higher connectivity of graph coloring complexes, Oct 25, 2006
Alexander Engström (with Michael Björklund), Characterizations of totally nonnegative matrices and a proof of a conjecture of Björner, Feb 14, 2007
Alexander Engström, A new subgraph counting identity, May 2, 2007
Alexander Engström, Discrete Morse functions from Fourier transforms, Sep 12, 2007
Alexander Engström, The topological Tverberg theorem, Oct 31, 2007
Alexander Engström, The geometry of cut polytopes, Sep 24, 2008
Alexander Engström, Topological representations of matroids, Oct 21, 2009
Alexander Engström, The geometry of resolutions of monomial ideals, Mar 17, 2010
Alexander Engström, Towards a theory of structural commutative algebra, Apr 21, 2010
Alexander Engström, Betti numbers of lattice ideals from discrete Morse theory, Feb 2, 2011
Alexander Engström, Ehrhart polynomials from ranking genes fast and a local Riemann hypothesis, Oct 19, 2011
Henrik Eriksson, Integraler, partitioner och MacMahons sats, Mar 14, 2007
Kimmo Eriksson, Limiting shapes of birth-and-death processes on Young diagrams, Nov 4, 2009
Niklas Eriksen, Permutations with prescribed descents, and fixed point colored permutations, May 5, 2008

Ragnar Freij, Equivariant discrete Morse theory, and the complex of connected graphs, Oct 8, 2008
Ragnar Freij, Hansen polytopes and the 3^d conjecture, Feb 29, 2012
Shmuel Friedland, Counting matchings in graphs with applications to the monomer-dimer models, Apr 16, 2008
Ralf Fröberg, Koszul algebras, Feb 4, 2009

Rafael Gonzalez D'Leon, Representing matroids by polynomials with the half-plane property, May 27, 2009
Mark Goresky, Subspace arrangements and equivariant cohomology, May 16, 2007

Christian Haase, Lattice Points and Adjunction, Mar 16, 2011
Olof Heden, Perfect codes vs. full rank perfect codes, Mar 7, 2007
Olof Heden, An introduction to vector space partition problems, Mar 9, 2011
Brian Hopkins, Bulgarian solitaire and related operations on partitions, Apr 30, 2009
Liza Huijse, What can cohomology tell us about many-particle quantum systems?, Jan 14, 2009
Axel Hultman, Twisted identities in Coxeter groups, Oct 11, 2006
Axel Hultman, Connections between inversion arrangements and Bruhat intervals, Sep 5, 2007
Axel Hultman, Points on tropical lines, Feb 20, 2008
Axel Hultman, Singularities of Schubert varieties and their relatives, (lärarprov), Sep 16, 2009
Axel Hultman, Inversion arrangements and Bruhat intervals, Apr 7, 2010

Federico Incitti, Dyck partitions, quasi-maximal quotients and Kazhdan-Lusztig polynomials, Nov 5, 2008

David M. R. Jackson, Geometrical conjectures associated with embeddings of graphs in surfaces, Oct 18, 2006
Svante Janson, Graph limits and exchangeable infinite random graphs, Mar 18, 2009
Jakob Jonsson, Simplicial complexes of permutations, Aug 29, 2007
Jakob Jonsson, Torsion in the homology of the chessboard complex, Sep 26, 2007
Jakob Jonsson, On how to detect torsion in the homology of a chain complex, Jan 30, 2008
Jakob Jonsson, Hard squares with negative activity on cylinders with odd circumference, Sep 3, 2008
Jakob Jonsson, On the topology of independence complexes of triangle-free graphs, Oct 14, 2009
Jakob Jonsson, The Cantini-Sportiello proof of the Razumov-Stroganov conjecture, Apr 28, 2010

Thomas Kahle, A taxonomy of commutative monoid congruences, Nov 10, 2010
Gil Kalai, A mathematical dialogue in discrete geometry with Jürgen Eckhoff, Jun 3, 2009
Gil Kalai, Analysis of Boolean functions: some results and two problems, May 23, 2012
Juhani Karhumäki, Beauty and challenges of combinatorics on words, Mar 3, 2010
Anatol Kirillov, Tropical Robinson-Schensted-Knuth correspondence, Nov 18, 2009
Christer Kiselman, Characterizing digital straightness using the chord property, word combinatorics, Diophantine inequalites, and difference operators, Dec 9, 2009
Christian Krattenthaler, Growth diagrams, and increasing and decreasing chains in fillings of cell diagrams, Mar 23, 2007
Martina Kubitzke, The Lefschetz property for barycentric subdivisions of shellable complexes, Nov 11, 2009

Urban Larsson, 2-pile Nim with a restricted number of move-size imitations, Nov 28, 2007
Juliane Lehmann, Some necessary conditions for the existence of vector space partitions, Mar 9, 2011
Matthias Lenz, Zonotopal algebra and Mason's conjecture, Jan 25, 2012
Alice Lesser, Optimal and hereditarily optimal realizations of metric spaces, Nov 19, 2008
Svante Linusson, On the independence complex of square grids, Nov 8, 2006
Svante Linusson, Liftable valuations of polytopes, Feb 7, 2007
Svante Linusson, Percolation on bunkbed graphs and a conjecture by Häggström, Oct 1, 2008
Svante Linusson, n! matchings, n! posets, Dec 16, 2009
Svante Linusson, The probability of the Alabama paradox, June 8, 2011

Klas Markström, Azuma-Hoeffding inequalities for matrix martingales and random expanders, May 7, 2008
Luca Moci, A Tutte polynomial for toric arrangements and zonotopes, Apr 6, 2011
Ivan Mogilnykh, Weak isometries of Preparata codes, Dec 2, 2009

Esmeralda Năstase, The minimum size of a finite subspace partition, Mar 9, 2011
Benjamin Nill, Hollow lattice polytopes and Ehrhart theory, May 20, 2009
Patrik Norén, Graph homomorphism ideals, May 27, 2009
Patrik Norén, Tree decomposition, Feb 17, 2010
Patrik Norén, Polytopes from Subgraph Statistics, Jan 19, 2011

Mikael Passare, Discriminantal coamoebas and zonotopes, Nov 7, 2007
Robert Parviainen, Constant term methods for lattice paths and their applications to Asymmetric Exclusion processes, Dec 12, 2007
Piotr Przytycki, Acute triangulations of polyhedra, Sep 23, 2009

Vic Reiner, Diameter of the graph of reduced words, May 6, 2009
Andrzej Rucinski, Dirac type problems for hypergraphs, Jun 10, 2009

Carsten Schultz, The equivariant topology of stable Kneser graphs Oct 21, 2011
Pascal Schweitzer, Aspects of the Graph Isomorphism Problem, Mar 28, 2012
Patrick Schweitzer, Competition Numbers, Quasi-Line Graphs and Holes, Apr 24, 2012
Papa Sissokho, The lattice of subspace partitions, Mar 9, 2011
Jonas Sjöstrand, Expected number of inversions after t random transpositions, Oct 20, 2010
Jonas Sjöstrand, Equidistributed statistics on matchings and permutations, Jan 26, 2011
Michael Shapiro, Directed planar networks in the disk and in the annulus, Nov 26, 2008
Tatiana Smirnova-Nagnibeda, Criticality of the Abelian Sandpile Model on self-similar graphs, Feb 1, 2012
Greg Smith, Eulerian numbers and Laurent polynomials, Sep 30, 2009
Stephen D. Smith, Poset combinatorics and cohomology of sporadic simple groups, Nov 2, 2011
Faina I. Solov'eva, On transitive partitions of the $n$-cube into binary codes, Oct 10, 2007
Frank Sottile, Combinatorial positivity in the Schubert calculus via dual equivalence graphs, Apr 13, 2011
Matthew Stamps, Topological representations of matroid maps, May 4, 2011
Benjamin Steinberg, Poset cohomology, Leray numbers and the global dimension of left regular bands, May 11, 2011
Klara Stokes, Some numerical semigroups in finite geometry, Apr 29, 2010
Seth Sullivant, Eulerian-Catalan Numbers, Mar 2, 2011

Martin Tancer, Hardness of embedding simplicial complexes in $R^d$, Oct 7, 2009
Bhalchandra Thatte, Reconstructing pedigrees, Nov 17, 2010

Hanna Uscka-Wehlou, Some combinatorial problems related to digital straight lines with irrational slopesand to balanced aperiodic words, Dec 2, 2009

Mikael Vejdemo Johansson, Species, derivatives of types and Gröbner bases for operads, Sep 1, 2010
Kathrin Vorwerk, Boolean involutions in the symmetric group, Nov 15, 2006
Kathrin Vorwerk, Buildings and chamber graph connectivity, Apr 23, 2008
Kathrin Vorwerk, Stanley's depth conjecture, Sep 10, 2008
Kathrin Vorwerk, The Grassmannian and the associahedron, Jan 20, 2010

Michelle Wachs, Homology of Rees products of posets and permutation enumeration, Oct 15, 2008
Thomas Westerbäck, Steiner triple systems and perfect codes, Apr 11, 2007

Benjamin Young, Domino shuffling for the Half-Hexagon graph, Feb 16, 2011

Piotr Zwiernik, Binary cumulant varieties, May 18, 2011.

Various artists, Open problems seminar, Mar 26, 2008
Various people, Open problems session, May 19, 2010

The combinatorics group in Stockholm