University of Vienna

Combinatorics Working Seminar

Previous Seminars

This is the weekly combinatorics working seminar organized by PhD students and postdocs in the combinatorics group at the University of Vienna. We promote a friendly atmosphere where students and members of the group have the opportunity to present their recent developments and/or interests in an informal setting. For this reason the talks are mainly addressed to students but senior academics are also welcome to attend.

Students and postdocs from other groups are very welcome to join!

The current schedule can be found here.

Summer Semester 2019


Coordinators: Cesar Ceballos and Hans Höngesberg
Jun. 27 Chen Wang How to tell if a number is prime
Jun. 20 No Seminar
Jun. 13 Josef Küstner A (not yet elliptic) analog of "a q-analog of the Fibonomial numbers"
Jun. 6 Manjil Saikia Refined enumeration of vertically and horizontally symmetric alternating sign matrices (VHSASMs)
May 30 No Seminar
May 23 Kim Won Hyok Summary on lozenge tiling problems and the methods to enumerate them
May 16 Cesar Ceballos A q-analog of the Fibonomial numbers
May 9 Ting Guo A symmetry property for stack polyominoes
May 2 Alex Miller On characters of symmetric groups II
Apr. 25 Florian Aigner Quadruple complementary plane partitions
Apr. 18 No Seminar
Apr. 11 Gaurav Bhatnagar Prime number conjectures from the Shapiro class structure

Winter Semester 2018/19


Coordinators: Florian Aigner and Cesar Ceballos
Jan. 31 Cesar Ceballos Two nested families of Dyck paths
Jan. 24 Alex Miller On characters of symmetric groups
Jan. 17 Manjil Saikia Hard and Easy Instances of L-Tromino Tilings
Jan. 10 Arindam Biswas Spectra of non-bipartite, finite Cayley graphs
Dec. 18* Julian Ritter The poset of regions of a hyperplane arrangement
Dec. 13 Florian Aigner A symmetric polynomial approach to alternating sign matrices
Dec. 6 Kim Won Hyok Introduction to lozenge tiling problems and Kuo condensation
Nov. 29 Josef Küstner Pyramidal Plane Partitions
Nov. 22 No Seminar Canceled
Nov. 15 Chen Wang A detailed analysis on the Borwein conjecture

Summer Semester 2018


Coordinators: Cesar Ceballos and Alex Miller
Jun. 28 Cesar Ceballos The n! and (n+1)^(n-1) conjectures
Jun. 21 No Seminar
Jun. 14 Ting Guo On a nonzero coefficient of binomial structured polynomials
Jun. 7 No Seminar Canceled
May 31 Holiday
May 24 Hans Höngesberg An Attempt Towards a Combinatorial Proof of the Operator Formula
May 17 Florian Aigner Evaluations of determinants related to alternating sign matrices leading to a new variation of a proof of the ASM theorem
May 10 Holiday
May 3 Chen Wang An asymptotic proof of Borwein's conjecture
Apr. 26 Gaurav Bhatnagar The determinant of an elliptic Sylvesteresque matrix
Apr. 19 Manjil Saikia Refined Enumeration of Symmetry Classes of ASMs

Winter Semester 2017/18


Coordinators: Cesar Ceballos and Alex Miller
Jan. 24 Cesar Ceballos Lattice walks and bicolored Dyck paths
Jan. 17 No Seminar
Jan. 10 Ting Guo Pattern avoidance in 0-1-fillings of Ferrers shapes
Dec. 20 Chen Wang An asymptotic approach to Borwein's conjecture
Dec. 13 Manjil Saikia L-Trimino tilings of some regions
Dec. 6 No Seminar SFB Status Seminar Strobl
Nov. 29 Tomack Gilmore PhD Defense
Nov. 22 Nishad Kothari Pfaffian Orientations and Conformal Minors: Part 2
Nov. 15 Nishad Kothari Pfaffian Orientations and Conformal Minors: Part 1
Nov. 8 Alex Miller Some problems involving some matrices in combinatorics

Summer Semester 2017


Coordinators: Cesar Ceballos and Vivien Ripoll
June 29
June 22 Tomack Gilmore Holey matrimony: marrying two approaches to a tiling problem
June 15 Feiertag
June 8 Manjil Saikia Alternating Sign Matrices: What, Why and How
June 1 Hans Höngesberg Enumeration of Halved Monotone Triangles
May 25 Feiertag
May 18 Myrto Kallipoliti Patterns in Dyck paths and Shi tableaux
May 11 Chen Wang Kirkman triple systems and large sets
May 4 Tomack Gilmore Signed perfect matchings and signed lattice paths enumeration
April 20 Florian Aigner Rectangular ASMs, FPLs and the 7-vertex model
April 13 Robin Sulzgruber Rational Shi Tableaux
April 6 Cesar Ceballos v-Tamari lattices: a simple proof of the lattice property

Winter Semester 2016/17


Coordinators: Cesar Ceballos and Vivien Ripoll