Talks

Advanced Topics in Combinatorics, Guest Lecture (virtual).
Vertex Partitions into an Independent Set and a Forest with Each Component Small.
Iowa State. 22 October 2019.

Advanced Topics in Combinatorics, Guest Lecture (virtual).
Using the Potential Method to Color Nearbipartite Graphs.
Iowa State. 20 October 2020.

Combinatorics Seminar (virtual).
Vertex Partitions into an Independent Set and a Forest with Each Component Small.
Shanghai Center for Mathematical Sciences. 15 October 2020.

Graphs and Matroids Seminar (Virtual).
Vertex Partitions into an Independent Set and a Forest with Each Component Small.
U of Waterloo. 28 September 2020.

Discrete Math Seminar (Virtual).
Vertex Partitions into an Independent Set and a Forest with Each Component Small.
CU Denver. 21 September 2020.

Graphs and Optimisation Seminar (Virtual).
Vertex Partitions into an Independent Set and a Forest with Each Component Small.
LaBRI, France. 24 July 2020.

WaterColor, Waterloo Coloring Conference.
Using the Potential Method to Color Nearbipartite Graphs.
Waterloo, ON. 24 September 2019.

Colourings, Independence & Domination 2019.
Using the Potential Method to Color Nearbipartite Graphs.
Piechowice, Poland. 17 September 2019.

Discrete Math Seminar.
Using the Potential Method to Color Nearbipartite Graphs.
VCU. 11 September 2019.

Combinatorics Seminar.
Using the Potential Method to Color Nearbipartite Graphs.
George Washington University. 30 August 2019.

CanaDAM 2019. Graph Decompositions Minisymposium.
Circular Coloring in Planar Graphs.
Vancouver, BC. 30 May 2019.

Atlanta Lecture Series in Combinatorics XXIII.
Circular Coloring of Planar Graphs.
Georgia Tech. 30 March 2019.

AMS Sectional Meeting. Special Session on Recent Developments in Graph Theory.
Circular Flows in Planar Graphs.
Auburn, AL. 16 March 2019.

AMS Sectional Meeting. Topics in Graph Theory, Hypergraphs and Set Systems.
Coloring Squares of Planar Graphs.
Ann Arbor, MI. 21 October 2018.

Combinatorics Seminar.
Coloring Squares of Planar Graphs.
Middle Tennessee State University. 5 October 2018.

SIAM Discrete Math 2018.
Acyclic Edgecoloring of Planar Graphs: Delta Colors Suffice when Delta is
Large.
Denver, CO. 4 June 2018.

Pi Mu Epsilon Induction Lecture.
Bootstrap Percolation Thresholds in Plane Tilings using Regular Polygons.
RandolphMacon College. 11 May 2018.

59th MIGHTY (MIdwest GrapH TheorY).
Bootstrap Percolation Thresholds in Plane Tilings using Regular Polygons.
West Virginia University. 28 April 2018.

Combinatorics Seminar.
Coloring Squares of Planar Graphs.
George Washington University. 6 March 2018.

Discrete Math Seminar.
Bootstrap Percolation Thresholds in Plane Tilings using Regular Polygons.
Virginia Commonwealth University. 21 February 2018.

International Workshop on Graph Theory.
Acyclic Edgecoloring Planar Graphs.
Ewha Womans University, Seoul, S. Korea. 4 January 2018.

DiscMath Seminar.
Edgecoloring of Graphs and Multigraphs.
Illinois State University. 19 October 2017.

Mathematics Colloquium and EXTREEMSQED Lecture.
Edgecoloring of Graphs and Multigraphs.
William & Mary. 8 September 2017.

Graph Theory Seminar.
Acyclic Edgecoloring Planar Graphs.
William & Mary. 8 September 2017.

Discrete Math Seminar.
Acyclic Edgecoloring Planar Graphs.
Virginia Commonwealth University. 6 September 2017.

29^{th} Cumberland Conference.
Edgecoloring Multigraphs.
Vanderbilt University. 20 May 2017.

Combinatorics, Algebra, and Geometry Seminar.
Edgecoloring of Graphs and Multigraphs.
George Mason University. 21 April 2017.

AMS Sectional Meeting. Topics in Extremal, Probabilistic and Structural Graph
Theory.
Listcoloring Clawfree Graphs with Δ1 Colors.
Bloomington, IN. 1 April 2017.

New Trends in Graph Coloring.
Coloring Line Graphs of Multigraphs with max(ω, ceil((5Δ+3)/6)
Colors.
Banff International Research Station (BIRS), Banff, Alberta. 20 October 2016.

Applied Math Department Seminar.
Edgecoloring Multigraphs.
Johns Hopkins University. 19 September 2016.

SIAM Discrete Math 2016.
Colorings Squares of Planar Graphs with Girth 5.
Atlanta, GA. 6 June 2016.

Discrete Math Seminar.
Hat Guessing Games.
Virginia Commonwealth University. 26 April 2016.

Discrete Math Seminar.
Colorings Squares of Planar Graphs with Girth 5.
Virginia Commonwealth University. 15 March 2016.

Discrete Math Seminar.
Regular Graphs are Antimagic.
Virginia Commonwealth University. 10 November 2015.

24^{th} Workshop Cycles & Colouring.
Fractional Coloring of Planar Graphs and the Plane.
High Tatras, Slovakia. 9 September 2015.

Discrete Math Seminar.
Fractionally Coloring the Plane.
Virginia Commonwealth University. 1 September 2015.

Connections in Discrete Mathematics: A Celebration of the Work of Ron Graham.
Planar Graphs are 9/2colorable.
Simon Fraser University. 16 June 2015.

28th Cumberland Conference.
Planar Graphs are 9/2colorable.
University of South Carolina. 15 May 2015.

Math Department Colloquium.
Planar Graphs are 9/2colorable and have Big Independent Sets.
George Mason University. 3 April 2015.

Math Department Colloquium.
Planar Graphs are 9/2colorable and have Big Independent Sets.
William & Mary. 20 March 2015.

Applied Math Department Seminar.
Planar Graphs are 9/2colorable and have Big Independent Sets.
Johns Hopkins University. 12 March 2015.

Math Department Colloquium.
Planar Graphs are 9/2colorable and have Big Independent Sets.
George Washington University. 6 February 2015.

Discrete Math Seminar.
Planar Graphs are 9/2colorable and have Big Independent Sets.
Virginia Commonwealth University. 27 January 2015.

Discrete Math Seminar.
A Proof of Bertrand's Postulate.
Virginia Commonwealth University. 2 December 2014.

Discrete Math Seminar.
An Introduction to Nowherezero Flows.
Virginia Commonwealth University. 25 November 2014.

Difference Equations Seminar.
Boundedness of Solutions to Reciprocal MaxType Difference
Equations.
University of Rhode Island. 15 October 2014.

Combintorics Seminar.
Painting Squares with Δ^{2}1 Shades.
University of Rhode Island. 15 October 2014.

Discrete Math Seminar.
Painting Squares with Δ^{2}1 Shades.
Virginia Commonwealth University. 7 October 2014.

West Fest. A celebration of the 60th birthday of Douglas B. West.
Graphs with χ = Δ have big cliques.
Minneapolis, MN. Institute for Math Applications. 20 June 2014.

SIAM Discrete Math 2014.
Painting Squares with Δ^{2}1 Shades.
Minneapolis, MN. 19 June 2014.

Cumberland Conference.
Graphs with χ = Δ have big cliques.
Morgantown, WV. 16 May 2014.

AMS Sectional Conference. Special Session on Difference Equations.
Boundedness of Solutions to Reciprocal MaxType Difference
Equations.
Baltimore, MD. 29 March 2014.

AMS Sectional Conference. Special Session on Graph Theory.
Graphs with χ = Δ have big cliques.
Knoxville, TN. 22 March 2014.

Discrete Math Seminar.
Starcoloring planar graphs with high girth.
Virginia Commonwealth University. 25 February 2014.

Discrete Math Seminar.
Coloring planar graphs via Discharging.
Virginia Commonwealth University. 18 February 2014.

Discrete Math Seminar.
An Introduction to Discharging: light subgraphs in planar graphs.
Virginia Commonwealth University. 11 February 2014.

Joint Math Meetings: Structural and Extremal Graph Theory.
Graphs with χ = Δ have big cliques.
Baltimore, MD. 16 January 2014.

Joint Math Meetings: Difference Equations.
Boundedness of Solutions to Reciprocal MaxType Difference
Equations.
Baltimore, MD. 15 January 2014.

Discrete Math Days of the Northeast, Invited Speaker.
Graphs with χ = Δ have big cliques.
Wesleyan University. 5 October 2013.

Discrete Math Seminar.
Graphs with χ = Δ have big cliques.
Virginia Commonwealth University. 1 October 2013.

Discrete Applied Math Seminar.
Graphs with χ = Δ have big cliques.
Illinois Institute of Technology. 13 September 2013.

Applied & Computational Math Seminar.
Boundedness of Solutions to Reciprocal MaxType Difference
Equations.
George Mason University. 6 September 2013.

Seminar.
Boundedness of Solutions to Reciprocal MaxType Difference
Equations.
Virginia Commonwealth University. 4 September 2013.

Seminar.
Coloring a clawfree graph with Δ1 colors.
East China Normal University, Shanghai, China. 12 April 2013.

Lecture.
Star coloring sparse graphs.
Zhejiang Normal University, Jinhua, China. 8 April 2013.

Seminar.
Coloring a clawfree graph with Δ1 colors.
Zhejiang Normal University, Jinhua, China. 7 April 2013.

Applied and Computational Math Division Seminar.
Revolutionaries and Spies in Graphs.
National Institute of Standards and Technology. 12 March 2013.

Undergrad Math Club.
A Proof of Bertrand's Postulate.
Wesleyan University. 5 March 2013.

Math Department Colloquium.
Revolutionaries and Spies in Graphs.
Howard University. 22 February 2013.

Discrete Math Seminar.
Coloring a clawfree graph with Δ1 colors.
University of Delaware. 19 February 2013.

Combinatorics, Algebra, Geometry Seminar (CAGS).
Coloring a clawfree graph with Δ1 colors.
George Mason University. 15 February 2013.

Discrete Math Seminar.
Coloring a clawfree graph with Δ1 colors.
West Virginia University. 31 January 2013.

Guest lecture in Kostochka's seminar class.
Listcoloring the square of sparse graphs.
University of Illinois. 23 January 2013.

Graph Theory and Combinatorics Seminar.
Coloring a clawfree graph with Δ1 colors.
University of Illinois. 22 January 2013.

Discrete Math Seminar.
Coloring a graph with Δ1 colors.
Virginia Commonwealth University. 11 September 2012.

SIAM Discrete Math. Minisymposium on Graph Coloring.
Conjectures equivalent to the BorodinKostochka Conjecture: Coloring a graph
with Δ1 colors.
Dalhousie University. Halifax, Nova Scotia. 18 June 2012.

Math Department Colloquium.
Revolutionaries and Spies in Graphs.
William & Mary. 30 March 2012.

Atlanta Lecture Series V.
Overlap Number of Graphs.
Emory. 26 February 2012.

Discrete Math Seminar.
Overlap Number of Graphs.
Virginia Commonwealth University. 22 February 2012.

Grad Student Seminar.
A Proof of Bertrand's Postulate.
Virginia Commonwealth University. 3 November 2011.

26th Clemson miniconference.
Revolutionaries and Spies.
Clemson. 27 October 2011.

Discrete Math Seminar.
Linear Coloring of Sparse Graphs.
Virginia Commonwealth University. 26 October 2011.

Combinatorics Seminar.
Revolutionaries and Spies.
Louisiana State University. 6 October 2011.

Student Colloquium.
The Search for Moore Graphs: Beauty is Rare.
Louisiana State University. 5 October 2011.

Student Colloquium.
A Proof of Bertrand's Postulate.
Louisiana State University. 4 October 2011.

AMS Sectional Conference. Special Session on Graph Theory.
Linear List Coloring of Sparse Graphs.
Wake Forest. 24 September 2011.

Combinatorics Seminar.
List Colorings of K_{5}minorfree Graphs with Special List Assignments.
University of South Carolina. 22 September 2011.

Discrete Math Seminar.
The Search for Moore Graphs: Beauty is a Rare Thing.
Virginia Commonwealth University. 21 September 2011.

Crossing Numbers Workshop.
Crossings, Colorings, and Cliques.
Banff International Research Station (BIRS), Banff, Alberta. 23 August 2011.

Research Experience for Graduate Students (REGS).
Graph Ramsey Theory.
University of Illinois. 22 June 2011.

24th Cumberland Conference.
Spies and Revolutionaries.
University of Louisville. 13 May 2011.

Combinatorics, Algebra, and Geometry Seminar.
Spies and Revolutionaries.
George Mason University. 29 April 2011.

SIAM Sectional Conference. Special Session on Graph Theory.
Spies and Revolutionaries.
UNCCharlotte. 26 March 2011.

Math Coffee.
A Proof of Bertrand's Postulate.
Davidson College. 25 March 2011.

Discrete Math Seminar.
Spies and Revolutionaries.
Virginia Commonwealth University. 9 February 2011.

Combinatorics Seminar.
List Colorings of K_{5}minorfree Graphs with Special List Assignments.
George Washington University. 18 November 2010.

Discrete Math Seminar.
List Colorings of K_{5}minorfree Graphs with Special List Assignments.
Virginia Commonwealth University. 17 November 2010.

Cycles and Colourings.
List Colorings of K_{5}minorfree Graphs with Special List Assignments.
High Tatras, Slovakia. 9 September 2010.

Seminar.
MakerBreaker Games: Building a Big Chain in a Poset.
West Virginia University. 22 July 2010.

Research Experience for Graduate Students (REGS) Seminar.
MakerBreaker Games: Building a Big Chain in a Poset.
University of Illinois. 20 July 2010.

SIAM Discrete Math. Minisymposium on Graph Theory.
List Colorings of K_{5}minorfree Graphs with Special List Assignments.
Austin, Texas. June 2010.

AMS Sectional Meeting. Minisymposium on Graph Theory.
List Colorings of K_{5}minorfree Graphs with Special List Assignments.
New Jersey Institute of Technology. 23 May 2010.

23rd Cumberland Conference.
List Colorings of K_{5}minorfree Graphs with Special List Assignments.
University of Mississippi. 20 May 2010.

Math Department Colloquium.
Reducibility and Discharging: An Introduction by Example.
US Naval Academy. 28 April 2010.

Discrete Math Seminar.
Detecting a Machine Failure in a Network: Vertex Identifying Codes.
University of Delaware. 9 April 2010.

Discrete Math Seminar.
MakerBreaker Games: Building a Big Chain in a Poset.
Virginia Commonwealth University. 5 March 2010.

Joint Math Meetings: SIAM Minisymposium on Graph Theory
MakerBreaker Games: Building a Big Chain in a Poset.
San Francisco, California. 15 January 2010.

Joint Math Meetings: Special Session on Applications of Graph Theory.
Detecting a Machine Failure in a Network: Vertex Identifying Codes.
San Francisco, California. 13 January 2010.

Discrete Math Seminar.
A New Lower Bound on the Density of Vertex Identifying Codes for the Infinite
Hexagonal Grid.
Virginia Commonwealth University. 24 September 2009.

MathFest 2009: Discrete Math Minisymposium.
Sorting Permutations by CutandPaste Moves.
Portland, Oregon. 6 August 2009.

2009 SIAM Annual Meeting: Graph Theory and Related Topics Minisymposium.
Injective Colorings of Sparse Graphs.
Denver, Colorado. 9 July 2009.

CanaDAM 2009: Graph Crossing Minisymposium.
Crossings, Colorings, and Cliques.
University of Montreal. 28 May 2009.

Combinatorics Seminar.
Crossings, Colorings, and Cliques.
Lafayette College. 30 April 2009.

Math Department Colloquium.
Coloring and Listcoloring of Graphs.
William & Mary. 24 April 2009.

Graduate Combinatorics Seminar.
Crossings, Colorings, and Cliques.
Rutgers University. 8 April 2009.

AMS Sectional Meeting: Special Session on Graph Theory.
Injective Colorings of Sparse Graphs.
University of Illinois. 28 March 2009.

Math Seminar.
Coloring and Listcoloring of Graphs.
University of Louisville. 16 February 2009.

Math Seminar.
Coloring and Listcoloring of Graphs.
Duquesne University. 13 February 2009.

Math Seminar.
Coloring and Listcoloring of Graphs.
Virginia Commonwealth University. 9 February 2009.

Graph Theory Minisymposium, I.
Entire (Δ+4)choosability of Plane Graphs with Δ≥ 8.
Joint Meetings, Washington, D.C. 6 January 2009.

Graduate Math Seminar.
The Probabilistic Method: How to make counting easy (sometimes).
Rutgers University. 5 December 2008.

Experimental Math Seminar.
Entire (Δ+4)choosability of Plane Graphs with Δ≥ 8.
Rutgers University. 30 October 2008.

Discrete Math Seminar.
Colorings, Crossings, and Cliques.
Columbia University. 21 October 2008.

Graduate Combinatorics Seminar.
Injective Colorings of Sparse Graphs.
Rutgers University. 17 September 2008.

Fete of Combinatorics and Computer Science: An international conference on combinatorics and computer science.
(7,2)edgechoosability of 3regular Graphs.
Keszthely, Hungary. 12 August 2008.

Midsummer Workshop on Combinatorics.
(7,2)edgechoosability of 3regular Graphs.
Charles University, Prague, Czech Republic. 29 July 2008.

SIAM Conference on Discrete Math: Minisymposium on Graph Coloring.
(7,2)edgechoosability of 3regular Graphs.
University of Vermont, Burlington. 19 June 2008.

DIMACS Research Experience for Undergraduates Seminar.
How Not to Give a Math Talk.
Rutgers University. 10 June 2008.

21st Cumberland Conference.
(7,2)edgechoosability of 3regular Graphs.
Vanderbilt University. 17 May 2008.

SIAM Conference on Optimization: Minisymposium on Graph Coloring for the Computation of Sparse Jacobians and Hessians.
How to Compute Jacobians More Efficiently or Coloring Highly Structured Graphs.
Boston, Massachusetts. 10 May 2008.

Computer Science Department Colloquium.
Discharging and Reducibility: An Introduction by Example.
Rutgers University, Camden. 9 April 2008.

Graduate Math Seminar.
The Search for Moore Graphs: Beauty is Rare.
Rutgers University. 4 April 2008.

Discrete Math Seminar.
Discharging and Reducibility: An Introduction by Example.
University of Delaware. 21 March 2008.

Mathematics Department Seminar.
Discharging and Reducibility: An Introduction by Example.
Montclair State University. 12 March 2008.

Discrete Math Seminar.
Star Coloring Planar Graphs with High Girth.
Princeton University. 6 March 2008.

Graduate Combinatorics Seminar.
(7,2)edgechoosability of 3regular graphs.
Rutgers University. 5 March 2008.

Combinatorics Seminar.
Regular Bipartite Graphs are Antimagic.
City University of New York. 13 February 2008.

Math Seminar.
Discharging and Reducibility: An Introduction by Example.
Bell Labs, Murray Hill, N.J. 14 December 2007.

Workshop on Algorithms, Combinatorics, and Geometry.
Discharging and Reducibility: An Introduction by Example.
University of North Texas. 29 November 2007.

Experimental Math Seminar.
Regular Bipartite Graphs are Antimagic.
Rutgers University. 11 October 2007.

AMS Regional Meeting.
Listcoloring the Square of a Subcubic Graph.
Depaul University. 5 October 2007.

DIMACS Mixer Series.
Listcoloring the Square of a Subcubic Graph.
DIMACS Center, Rutgers University. 19 September 2007.

20th Cumberland Conference.
Regular Bipartite Graphs are Antimagic.
Emory University. 17 May 2007.

44th Midwestern Graph Theory Conference (MIGHTY).
Regular Bipartite Graphs are Antimagic.
Wright State University. 11 May 2007.

Combinatorics Seminar.
Regular Bipartite Graphs are Antimagic.
University of Illinois at UrbanaChampaign.
1 May 2007.

Seminar.
Listcoloring the Square of a Subcubic Graph.
Bell Labs, Murray Hill, N.J.
30 March 2007.

Seminar.
Listcoloring the Square of a Subcubic Graph.
DIMACS Center, Rutgers University.
29 March 2007.

Discrete Math Seminar.
Coloring and Listcoloring of Graphs.
Iowa State University. 27 March 2007.

Midwest Theory Day.
Listcoloring the Square of a Subcubic Graph.
Purdue University.
2 December 2006.

43rd Midwestern Graph Theory Conference (MIGHTY).
Listcoloring the Square of a Subcubic Graph.
IndianaPurdue University at Fort Wayne.
4 November 2006.

Graph Theory Seminar.
Listcoloring the Square of a Subcubic Graph.
Georgia Institute of Technology.
12 October 2006.

DiscMath Seminar.
Listcoloring the Square of a Subcubic Graph.
Illinois State University.
5 October 2006.

Combinatorics Seminar.
Listcoloring the Square of a Subcubic Graph.
University of Illinois at UrbanaChampaign.
19 September 2006.

SIAM Conference on Discrete Mathematics.
Edgechoosability of Planar Graphs with no Two Adjacent Triangles.
University of Victoria, British Columbia.
26 June 2006.

DIMACS/DIMATIA/Renyi Combinatorial Challenges Meeting.
Edgechoosability of Planar Graphs with no Two Adjacent Triangles.
DIMACS Center, Rutgers University.
29 April 2006.

DiscMath Seminar.
List Edgecolorability of Planar Graphs with no Two Adjacent Triangles.
Illinois State University. 2 March 2006.

Midwest Theory Day.
List Edgecolorability of Planar Graphs with no Two Adjacent Triangles.
University of Wisconsin at Milwaukee.
10 December 2005.

Combinatorics Seminar.
List Edgecolorability of Planar Graphs with no Two Adjacent Triangles.
University of Illinois at UrbanaChampaign.
15 November 2005.

Graph Theory with Altitude (in honor of Joan Hutchinson's 60th Birthday).
A Strong Edgecoloring of Graphs with Maximum Degree 4 using 22 Colors.
University of Colorado at Denver.
16 May 2005.

Midwest Theory Day.
A Strong Edgecoloring of Graphs with Maximum Degree 4 using 22 Colors.
University of Illinois at UrbanaChampaign.
8 May 2005.

Combinatorics Seminar.
A CutandPaste Sorting Algorithm for Permutations.
University of Illinois at UrbanaChampaign.
12 April 2005.

Midwest Theory Day.
Sorting Permutations by Shifts, Flips, and ShiftFlips.
Depaul University.
4 December 2004.

Combinatorics Seminar.
Strong Edgecoloring of Graphs with Maximum Degree 4.
University of Illinois at UrbanaChampaign.
28 October 2003.
Back to my homepage.