University of Miami Combinatorics Seminar

Organizers: Bruno Benedetti, José Alejandro Samper, and Michelle Wachs


When not specified, we meet at 5pm on Mondays, in Ungar Building, Room 402.

Click on the dates for the abstracts.


FALL 2017

August 21: José Alejandro Samper (U Miami), Hopf Algebras in Combinatorics

August 28: José Alejandro Samper (U Miami), Hopf Algebras in Combinatorics

September 4: Labor Day

September 11: Brittney Ellzey (U Miami), CANCELLED DUE TO IRMA

September 11: James McKeown (U Miami), CANCELLED DUE TO IRMA

September 18: José Alejandro Samper (U Miami), CANCELLED DUE TO IRMA

September 25: Tiago Novello de Brito (Pontifícia Universidade Católica do Rio de Janeiro), Discrete Line Field

October 2: Michelle Wachs (U Miami), TBA

October 9: Workshop at MSRI; no seminar this week

October 16: José Alejandro Samper (U Miami), Hopf Algebras in Combinatorics

October 23: Manuel Rivera (U Miami), TBA



Past sessions


January 23: Richard Stanley (U Miami & MIT), Counting with congruence conditions

January 30: Bruno Benedetti (U Miami), Mogami constructions of manifolds from trees of tetrahedra

February 6: José Samper Casas (UM), On conjectural relatives of matroid polytopes

February 13: Brittney Ellzey (UM), A directed graph generalization of chromatic quasisymmetric functions

February 17, 4pm: Sebi Cioaba (U Delaware), Simplicial rook graphs: algebraic and combinatorial properties

February 20: Hai Long Dao (U Kansas), On local-global phenomena in the Betti tables of Stanley-Reisner ideals

February 27: Yuval Roichman (Bar-Ilan U, Israel), Cyclic descents of standard Young tableaux

February 28 Tue., 5PM (colloquium): Ron Adin (Bar-Ilan U, Israel), Cyclic descents, toric Schur functions and Gromov-Witten invariants

March 6: Laura Escobar (Urbana Champaign), Rhombic tilings and Bott-Samelson varieties

March 7 Tue., 5PM (colloquium): Anders Björner (KTH, Sweden), Around codimension one embeddings

March 13: Spring break

March 20: Fabrizio Zanello (Michigan Tech), Partition into distinct parts and unimodality

March 27: Tewodros Amdeberhan (Tulane), Determinants in "Wonderland"

April 3: Felix Gotti (UC Berkeley), Dyck paths and positroids from unit interval orders

April 10: Passover (no seminar this week)

April 17: Michelle Wachs (U Miami), On r-inversions and symmetric functions

April 24: Vasu Tewari (U Washington), Labeled binary trees, Schur-positivity and generalized Tamari lattices


FALL 2016

August 29: Hailun Zheng (U Washington), A characterization of simplicial manifolds with g2 ≤ 2

September 5: Labor day (no seminar this week)

September 12: Jay Yang (U Wisconsin-Madison), Random toric surfaces and a threshold for smoothness

September 19: Alessio Sammartano (Purdue), Blowup algebras of rational normal scrolls

September 24-26: AMS Sectional meeting (Maine), no seminar this week

October 3: Nancy Abdallah (Linkoeping U, Sweden), Bruhat order on twisted identities and KLV polynomials

October 6 (Colloquium): Frank H. Lutz (TU Berlin, Germany), On the Topology of Steel

-- canceled due to hurricane Matthew

October 17: Anastasia Chavez (UC Berkeley), The Dehn-Sommerville relations and the Catalan matroids

October 24: Rainer Sinn (Georgia Tech), Positive semidefinite matrix completion and free resolutions

October 31: Katharina Jochemko (TU Wien, Austria), Discrete vs. continuous valuations: similarities and differences

November 7: Alex Lazar (UM), Filtered geometric lattices

November 14: John Shareshian (Washington U.), Subrack lattices of group racks

November 21: Jim Haglund (U Penn), LLT polynomials and the chromatic symmetric function of unit interval orders



January 25: Alex Engström (Aalto U, Finland), Boolean Statistics

February 1, 4pm: Richard Stanley (UM & MIT), Parking functions and their generating function. (Please note unusual time)

February 9 (!): Yuval Roichman (Bar-Ilan U, Israel), Geometric grid classes and symmetric sets of permutations

February 15: Matteo Varbaro (U Genova, Italy), Dual graphs and the Castelnuovo-Mumford regularity of subspace arrangements

February 22:  Russ Woodroofe (Mississippi State), A Broad Class of Shellable Lattices

February 29, 4pm:  Cynthia Vinzant (North Carolina State U), Real stable polynomials, determinants, and matroids. (Please note unusual time)

March 7: spring break

March 14, 4pm: Mark Skandera (Lehigh U), Evaluations of the power sum traces at Kazhdan-Lusztig basis elements of the Hecke algebra. (Please note unusual time)

March  17 (!): Emanuele Delucchi (U Fribourg, Switzerland), Toric arrangements and group actions on semimatroids

March 21: Luca Moci (Jussieu-Paris 7, France), Higher dimensional colorings and flows, arithmetic Tutte polynomials, and convolution formulae

March 28: James McKeown (UM), The combinatorics of the Waldspurger decomposition

April 4: Marty Golumbic (U Haifa, Israel), New and Old Graph Dimension Parameters

April 11, 4pm: Efrat Engel Shaposhnik (MIT), Dissertation Defense: Antichains of Interval Orders and Semiorders, and Dilworth Lattices of Maximum Size Antichains

April 18: Brittney Ellzey (UM), The Chromatic Quasisymmetric Function of the Cycle

April 25: Miriam Farber (MIT), Weak Separation, Pure Domains, and Cluster Distance


FALL 2015

September 21: Michelle Wachs (UM), Weighted bond posets and graph associahedra I

September 28: Michelle Wachs (UM), Weighted bond posets and graph associahedra II

October 5: Florian Frick (Cornell), Tverberg-type theorems and zero sum problems

October 12: Ivan Martino (U Fribourg, Switzerland),  Arrangements of subspaces for finite groups and their geometrical applications

October 17-18: AMS sectional meeting (Memphis); no seminar this week

October 26: Bennet Goeckner (Kansas U),  A non-partitionable Cohen-Macaulay complex

November 2: Brittney Ellzey (UM), Power sum expansion of the chromatic quasisymmetric functions

November 10 (!): Jose Samper (U Washington), Relaxations of the matroid axioms.
 5pm, Ungar 402 -  note the change of date!

November 16: Bruno Benedetti (UM), Optimal discrete Morse vectors are not unique.

November 23: Thanksgiving break. Enjoy!

November 30: Barbara Bolognese (Northeastern U, Boston),  Dual graphs of projective curves.

December 7: Carolina Benedetti (Fields Institute and York U, Toronto, Canada): Chromatic symmetric functions on simplicial complexes