AMS Special Session on

Enumerative and Extremal Problems in Chromatic Graph Theory

AMS Spring 2022 Western Sectional Meeting (online)

May 14-15th, 2022

Enumerative and Extremal Problems in Chromatic Graph Theory

Starting from the famous four-color conjecture in the mid-19th century, graph coloring problems have been a central theme in graph theory and combinatorics. Birkhoff's introduction in 1912 of the chromatic polynomial for counting colorings built a bridge between algebra and chromatic graph theory. The chromatic polynomial and its generalizations such as Stanley's chromatic symmetric function are an active and essential part of algebraic combinatorics. In extremal combinatorics, the questions arising out of graph colorings and its generalizations such as list colorings (from 1970s), and DP- or Correspondence colorings (from 2015) as well as related covers are a driving force for a variety of widely studied research questions.

However, there is minimal academic interaction between researchers studying enumerative coloring problems in algebraic combinatorics, and those studying extremal and enumerative coloring problems in the graph theory community. This special session proposes to bring together researchers from both these communities that have in recent years made advances in our understanding of enumerative and extremal problems in graph coloring and its generalizations, and help build connections for cross-fertilization of ideas between these research communities.

To ensure all sections of our research communities have an opportunity to participate in this session, out of the eighteen invited speakers, twelve are junior researchers, including graduate students, and eight are women researchers.


Hemanshu Kaul, Illinois Institute of Technology

Stephen Hartke, University of Colorado Denver

Invited Speakers

  • James Anderson, Georgia Tech (webpage)

  • Farid Aliniaeifard, University of British Columbia, Canada (webpage)

  • Anton Bernshteyn, Georgia Tech (webpage)

  • Logan Crew, University of Waterloo, Canada (webpage)

  • Ewan Davies, University of Colorado Boulder (webpage)

  • Fengming Dong, Nanyang Technological University, Singapore (webpage)

  • Joanna Ellis-Monaghan, University of Amsterdam, Netherlands (webpage)

  • Krystal Guo, University of Amsterdam, Netherlands (webpage)

  • Ross Kang, Radboud University, Nijmegen, Netherlands (webpage)

  • Reem Mahmoud, Virginia Commonwealth University (recent work)

  • Jessica McDonald, Auburn University (webpage)

  • Jeff Mudrock, College of Lake County (webpage)

  • Songling Shan, Illinois State University (webpage)

  • Gunjan Sharma, Illinois Institute of Technology (recent work)

  • Sophie Spirkl, University of Waterloo, Canada (webpage)

  • Foster Tom, University of California Berkeley (webpage)

  • Stephanie van Willigenburg, University of British Columbia, Canada (webpage)

Schedule of Talks

Saturday Morning, May 14th

8am-8:30am Logan Crew : Graph Bases from the Chromatic Symmetric Function [Slides]

8:40am-9:10am Joanna Ellis-Monaghan : Applying the V-polynomial to list coloring and symmetric functions [Slides]


9:30am-10am Krystal Guo : Transversal polynomial of covers of graphs [Slides]

10:10am-10:40am Songling Shan : Some recent progress towards the overfull conjecture [Slides]

Saturday Afternoon, May 14th

2pm-2:30pm Anton Bernshteyn : Smoothness and colorings [Slides]

2:40pm-3:10pm Gunjan Sharma : DP-Coloring Cartesian Products of Graphs using the DP Color Function [Slides]


3:30pm-4pm Stephanie van Willigenburg : Noncommutative chromatic symmetric functions revisited [Slides]

4:10pm-4:40pm Farid Aliniaeifard : The chromatic symmetric function of a graph centred at a vertex [Slides]

Sunday Morning, May 15th

8am-8:30am Fengming Dong : DP color functions versus chromatic polynomials [Slides]

8:40am-9:10am Jeff Mudrock : On Chromatic Polynomials, List Color Functions, and DP Color Functions [Slides]


9:30am-10am Ross Kang : Chromatic structure of bipartite graphs [Slides]

10:10am-10:40am Ewan Davies : Bounding the (list) chromatic number of triangle-free graphs [Slides]


11am-11:30am James Anderson : Coloring graphs with forbidden almost bipartite subgraphs [Slides]

Sunday Afternoon, May 15th

2pm-2:30pm Sophie Spirkl : Graph decompositions and the chromatic symmetric function [Slides]

2:40pm-3:10pm Foster Tom : Horizontal-strip LLT polynomials [Slides]


3:30pm-4pm Reem Mahmoud : Kempe Equivalent List Colorings [Slides]

4:10pm-4:40pm Jessica McDonald : Strong 4-colourings of graphs [Slides]

All listed times are Pacific Daylight Time.

Important Links and Deadlines

  • AMS webpage for the Spring 2022 Western Sectional Meeting and this Special Session

  • Abstract submission

    • By AMS policy, speakers must be registered for the meeting: registration page.

    • Abstracts should be submitted online through the AMS: abstract submission. Note that the system used for abstract submission is different than that used by the AMS in the past. You must be registered for the meeting to submit an abstract.

    • Deadline for abstract submission: March 15th 2022 (this is a firm deadline!)

  • Schedule of talks (see above)