ISU DISCRETE MATHEMATICS SEMINAR
Archive

Click here for the current seminar page.  To speak, please contact Bernard Lidicky (lidicky AT iastate DOT edu)



Fall 2017 Schedule

See current seminar page.

Spring 2017 Schedule

Date Speaker Title
Jan 10
Jan 17 Zhanar Berikkyzy Antimagic Labelings of Weighted and Oriented Graphs
Jan 24 ---
Jan 31 ---
Feb 7 Michael Dairyko Ore and Chvatal-type Degree Conditions for Bootstrap Percolation from Small Sets
Feb 7 Juergen Kritschgau The rainbow numbers of graphs with respect to 2-matchings and 3-matchings
Feb 9
Thursday
Xavier Pérez Giménez Perfect matchings and Hamilton cycles in the preferential attachment model.
Feb 14 Alex Shulte Anti-van der Waerden number of $3$-term arithmetic progressions
Feb 14 Kevin Moss Packing Coloring on Infinite Lattices
Feb 21 Matthew Yancey Counting walks in a digraph
Feb 28 Andrew Suk
Colloquium
On the Erdos-Szekeres convex polygon problem
Mar 3
Friday! 2:10pm 401 Carver
Jeremy Alm From Ramsey Theory to Relation Algebra: graph coloring, algorithms, projective geometry, Fourier analysis, the universe, and more!
Mar 7 Matt Beck Partially Magic Labelings and the Antimagic Graph Conjecture
Mar 14 Spring break
Mar 21 Adam Blumenthal A Bound on the Secure Domination Quotient of $r$-connected Graphs
Mar 21 Bernard Lidicky Decomposing Random $d$-regular Graphs Into Stars
Mar 28 Cory Palmer
Mar 30
Thursday! 4:10pm 268 Carver
Heather Smith Sampling and Counting Genome Rearrangement Scenarios
Apr 4 Jephian Lin Note on von Neumann and R\'enyi entropies of a graph
Apr 4 Isaac Wass Rainbow paths and trees in properly-colored graphs
Apr 11 EGR PSD throttling on a graph
Apr 18 EGR Impact of graph operations on the minimum number of distinct eigenvalues of a graph
Apr 20
Thursday! 2:10pm 204 Carver
Jan Volec The codegree threshold of $K_4^-$
Apr 25 EGR Families of graphs with maximum nullity equal to zero forcing number
May 30 Zdenek Dvorak Chromatic number of triangle-free graphs

Fall 2016 Schedule

Date Speaker Title
Aug 1 Bangteng Xu
10-10:50 AM, Carver 401
Nonlinear functions and difference sets on group actions
Aug 23 Organizational Meeting
Aug 25 Thursday Jan Foniok
2:15-3:00 PM, Carver 401
Multiplicative graphs and the product colouring conjecture
Aug 30 Bernard Lidický 3-coloring triangle-free planar graphs
Aug 30 Tuesday László Székely
4:10-5:00 PM, Carver 204
Using the Lovász Local Lemma for asymptotic enumeration (Colloquium)
Sep 6 Kristin Heysse Building a graph an edge at a time
Sep 13 Alex Neal-Riasanovsky Chromatic Ramsey numbers and coloring triple systems
Sep 20 Steve Butler Some basics on parking functions
Sep 27 Shanise Walker; Bernard Lidický Injective colorings-GRWC Update; Independent sets near the lower bound in bouded degree graphs
Oct 4 Kritin Heysse, Zhanar Berikkyzy Constructions for distance cospectral graphs; Anti-van der Waerden numbers of 3-term arithmetic progressions
Oct 11 Robert Lazar q-Analogue t-Designs over Galois Fields (Prelim)
Oct 18 Travis Peters LIGHTS OUT! on Cartesian Products
Oct 25 Ryan Martin An asymptotic multipartite Kühn-Osthus theorem
Oct 31 Monday Éva Czabarka 2:15-3:00 PM, Carver 401 Problems related to the joint degree vector
Nov 1 Michael Tait Four conjectures in spectral extremal graph theory
Nov 8 Adam Wagner Tutorial on the Container Method
Nov 15 Andrew Uzzell Entropy and counting for multicolored graph limits
Nov 17 Thursday John Goldwasser 2:15-3:00 PM, Carver 401 Switching vertices, Fibonacci polynomials, grid graphs, and more
Nov 22 nobody Thanksgiving break
Nov 29 Kevin Moss
Dec 6

Spring 2016 Schedule

Date Speaker Title
Jan 12 Organizational meeting
Jan 14 Florian Pfender (University of Colorado Denver)
Room Carver 0204
Clique degrees in random graphs
Jan 19 Aditya Ramamoorthy Combinatorial Designs for distributed data storage and distributed function computation
Jan 26 Steve Butler Generalizations of Eulerian numbers
Feb 2 Zdenek Dvorak (Charles University) Classes of graphs with sublinear separators (Colloquium)
Feb 9 Bernard Lidicky Precoloring vertices in triangle-free planar graphs
Feb 16 Jozef Skokan (LSE)
Room Carver 0274
The Multicolour Ramsey Number of a Long Odd Cycle
Feb 23 Jephian Lin Report for Advanced Course on Combinatorial Matrix Theory, CRM
Mar 1 Chassidy Bozeman Zero Forcing, Power Domination, and Power Propagation Time
Mar 3 Jessica De Silva
Room Carver 0274, 2:10-3pm
If All You Have is Thor’s Hammer
Mar 8 Cancelled (Boca)
Mar 15 Spring break
Mar 22 Theo Molla
Room Carver 0274, 2:10-3pm
Factors in graphs, weighted graphs and directed graphs
Mar 29 Alexander Roitershtein (ISU) On Wallis-type products and Polya's urn schemes
Apr 5 Sarka Petrickova The typical structure of maximal triangle-free graphs [slides]
Apr 12 Edinah Gnang Combinatorial aspects of the algebra of matrices and hypermatrices with applications
Apr 13
Wednesday
Michelle Delcourt
Room Carver 401, 1:10-2pm
Intersecting Families of Permutations
Apr 14
Thursday
Luke Postle
Room Carver 401, 2:10-3pm
How many colors can be saved?
Apr 19 Fargo Report
Jun 2 Ilkyoo Choi
Room Carver 401, 3:10-4pm
Improper colorings of graphs on surfaces
Jun 13
Monday
Jan Volec
Room Carver 290, 3:10-4pm
Subcubic triangle-free graphs have fractional chromatic number at most 14/5
Jun 20
Monday
Ping Hu
Room Carver 290, 3:10-4pm
Minimum number of edges that occur in odd cycles
Jun 27
Monday
Taisa Martins
Room Carver 401, 1:30-2:20pm
Graph Limits - Finite Forcibility and Computability

Fall 2015 Schedule

Date Speaker Title
Aug 5 Jan Volec (ETH Zurich) Properly colored and rainbow copies of graphs with few cherries
Aug 11 Ilkyoo Choi (KAIST) A step towards both Geelan's Conjecture and Gyárfás' Conjecture
Sep 1 Michael Young An EGR Report
Sep 8 Derrick Stolee $(4,2)$-Choosability of Planar Graphs: A Working Seminar Report
Sep 15 John Talbot (University College London) Structural properties of certain symmetric 2-designs
Sep 15 David Offner (Westminster College) Polychromatic Colorings of the Hypercube (colloquium)
Sep 22 Kevin Palmowski Fractional Zero Forcing via Three-color Forcing Games
Sep 29 Armando Grez New upper bounds on the distance domination number of grids
Sep 29 Steve Butler Aspects of the normalized Laplacian matrix
Oct 6 Mike Dairyko and Kevin Moss A Report on the AMS Central Sectional Meeting
Oct 13 Michael Ross Edge-Reconstruction Conjecture Disproven! (No, not that one.) : Leveraging Swappability to Examine Open Problems in Edge-Reconstruction
Oct 20 Jan Hubicka (University of Calgary) Ramsey classes - properties, examples and constructions
Oct 26 Sarah Loeb (University of Illinois) Fractional Separation Dimension
Oct 27 Axel Brandt (University of Colorado Denver) Short Cycles in Graphs
Nov 3 Daniela Ferraro (Texas State University) The power domination problem in graphs
Nov 10 Zhanar Berikkyzy The edit distance of powers of cycles
Nov 17 Kirsten Hogenson A random version of the $r$-fork-free theorem
Nov 24 No Seminar: Thanksgiving Break
Dec 1 Chassidy Bozeman The Tree Cover Number of a Graph

Spring 2015 Schedule

Date Speaker Title
Jan 26 Ryan Martin Diamonds are Forever
Feb 2 Leslie Hogben Nordhaus-Gaddum Sum Problems for Tree-width and Colin de Veriére Parameters
Feb 8 Zdenek Dvorak (Charles U) Towards dichotomy for planar boolean CSP. (Colloquium)
Feb 16 Jephian C.H. Lin Odd cycle zero forcing parameters and the minimum rank of graph blowups
Feb 23 Sung-Yell Song Structural properties of certain symmetric 2-designs
Mar 2 Steve Butler Edge flipping on the complete graph
Mar 9 Katy Nowak Partial geometric designs with prescribed automorphisms
Mar 23 Maryam Sharifzadeh (U Illinois) Sharp bound on the number of maximal sum-free subsets of integers
Mar 24 Hong Liu (U Illinois) The typical structure of maximal triangle-free graphs
Apr 9 Daniel Král (U Warwick) Analytic approach to discrete problems (Colloquium)
Apr 13 Kristin Heysse Cospectral graphs by toggling
Apr 27 Christopher Cox Ordered and partially-ordered variants of Ramsey's theorem (M.S. thesis defense)
May 7 Edray Goins (Purdue U) The Intersection of Graph Theory, Group Theory, and Differential Geometry (Colloquium)

Fall 2014 Schedule

Date Speaker Title
Aug 26 Organizational Meeting
Sep 2 Working Seminar Problem Presentations for Working Seminar
Sep 2 Colloquium 4:10-5:00pm, 204 Carver
Derrick Stolee Automated Discharging Arguments for Density Problems in Grids
Sep 9 Canceled due to IMA Workshop: Probabilistic and Extremal Combinatorics.
Sep 16 Mohit Kumbhat Conflict-free coloring of hypergraphs
Sep 23 Kirsten Hogenson Tiling tripartite graphs with 3-colorable graphs: The extreme case
Sep 30 Alex Schulte Directed graphs of Commutative Rings with Identity
Oct 7 Christopher Cox Ordered Ramsey numbers of loose paths and matchings
Oct 14 No seminar.
Oct 21 Derrick Stolee Strong Chromatic Index: A GRWC Report
Oct 28 Jennifer Diemunsch
University of Colorado Denver
Degree Sequence Packings
Nov 4 Colloquium 4:10-5:00pm, 204 Carver
David Galvin
Notre Dame University
Stirling numbers of graphs, and the normal ordering problem.
Nov 11 No Seminar
Nov 18 No Seminar
Nov 25 Canceled due to Thanksgiving Break
Dec 2 No Seminar
Dec 9 No Seminar

2014 Spring

Date Speaker Title
Jan 14 No seminar
Jan 21 Lucas Kramer On extremal configurations in the Boolean lattice
 Jan 28 No seminar: Working Seminar (writing committee)
T, Jan 28 Colloquium: Hao Huang, Rutgers/IAS The minimum number of nonnegative edges in hypergraphs
W, Jan 29 Colloquium: Bernard Lidický, University of Illinois Applications of flag algebras in hypercubes and permutations
Feb 04 No seminar: Working Seminar (writing committee)
W, Feb 05 Colloquium: Elad Aigner-Horev, University of Hamburg Transference problems in combinatorics
M, Feb 10 Colloquium: Michael Young, Iowa State University Ramsey and anti-Ramsey multiplicities
Feb 11 No Seminar: Working Seminar (writing committee)
T, Feb 11 Colloquium: Xavier Pérez-Giménez, University of Waterloo Arboricity and spanning-tree packing in random graphs with an application to load balancing
M, Feb 17
MECS Interdisciplinary Seminar: Ryan Martin Vertex-identifying codes in graphs
 Feb 18 Chin-Hung Lin The sieving process and lower bounds for the minimum rank problem
Su, Feb 23 Pi Mu Epsilon (Math Club): Ryan Martin Can a Venn diagram be made with 4 circles?
M, Feb 24 MECS Interdisciplinary Seminar: Ryan Martin Path-separation number in graphs
Feb 25 Paul Wenger, Rochester Institute of Technology Graph saturation in multipartite graphs
M, Mar 03 MECS Interdisciplinary Seminar: Tim McNicholl  
Mar 04 No seminar
M, Mar 03 MECS Interdisciplinary Seminar: Tim McNicholl  
Mar 11 No seminar: Working Seminar (writing committee)
Mar 18-22 Spring Break, No Seminar
Mar 25 No seminar: Working Seminar (writing committee)
Apr 01 No seminar: Working Seminar (writing committee)
Apr 08 Richard Mycroft, University of Birmingham, UK Packing k-partite k-graphs
Apr 15 Katy Nowak 1.5-difference families
Apr 22 Early Graduate Research (EGR) talks: Chassidy Bozeman, AnnaVictoria Ellsworth, Aaron Rodriguez and James Strickland Minimum rank of graphs with loops, part I
Apr 29 Early Graduate Research (EGR) talks: Jephian Chin-Hung Lin, Gabi Maurer and Kathleen Nowak Minimum rank of graphs with loops, part II

2013 Fall

Date Speaker Title
Aug 27 Organizational Meeting
Sep 03 NO SEMINAR, second hour of working seminar
F, Sep 06
Honors Salon: Steve Butler The mathematics of juggling
Su, Sep 08 Math Club/Pi Mu Epsilon (ΠΜΕ): Steve Butler The 291 decillion ways to tile with Tetris
Sep 10 Steve Butler Permutations which avoid the patterns 1324 and 2(14)3
R, Oct 15 Computer Science Department colloquium: Derrick Stolee Computational combinatorics and the search for uniquely Kr-saturated graphs
Sep 17 Michael Young The anti-Ramsey number of a matching
Sep 24 Derrick Stolee On independent sets in Cayley graphs over Z
Oct 01 James Carraher, University of Nebraska-Lincoln Compatible circuits in colored eulerian digraphs
M, Oct 07
MECS Interdisciplinary Seminar: Leslie Hogben Minimum rank problems
Oct 08 C. H. Lin Counterexamples to an edge spread question for zero forcing number
Oct 15 Minnie Catral, Xavier University Principal rank characteristic sequences
Oct 15
Colloquium: Ryan Martin The edit distance in graphs
Oct 22
Colloquium replaces seminar: Mike Ferrara, University of Colorado-Denver Realization problems for degree sequences
M, Oct 28 MECS Interdisciplinary Seminar: James Ostrowski, University of Tennessee-Knoxville Symmetry in integer programming
Oct 29 James Ostrowski, University of Tennessee-Knoxville Constraint orbital branching
Nov 05 Cathy Erbes, University of Colorado-Denver Extremal problems for degree sequences
Nov 12 Nicole Kingsley Propagation time for skew-symmetric zero forcing
Nov 19 Nathan Warnberg Positive semidefinite migration
Nov 25-29: Thanksgiving Break, No Seminar
M, Dec 02
MECS Interdisciplinary Seminar: Derrick Stolee Combinatorial Generation in the Presence of Symmetry  
Dec 03 Ryan Martin On matrices and quadratic programs
M, Dec 09 MECS Interdisciplinary Seminar: Derrick Stolee Generating p-extremal graphs

2013 Spring

Date Speaker Title
Jan 15 Organizational Meeting
Jan 22 Colloquium: Sebastian Cioaba, University of Delaware Algebraic methods in combinatorics
Jan 29 Srikanta Tirthapura (ECpE, ISU) On optimality of clustering by space filling curves
Feb 12 Leslie Hogben The graph complement conjecture:
Nordhaus-Gaddum type problems for minimum rank and Colin de Verdière parameters
Feb 19 Nicole Kingsley Propagation time for zero forcing on a loop graph
T, Feb 26 Colloquium: Amanda Ruiz, Binghamton University Realization of phased matroids
Th, Feb 28
Saad El Zanati, Illinois State University On decomposing regular graphs and multigraphs into isomorphic trees
T, Mar 05 Colloquium: Chi-Kwong Li, College of William and Mary Factorization of permutation matrices
Mar 12 Steven Osborne Report on 44th Southeastern Conference
Mar 18-22: Spring Break, No Seminar
Mar 26 Craig Erickson Sign patterns that require eventual exponential nonnegativity
Apr 02 Lucas Kramer Report on the EXCILL 2 Conference
Apr 09 Nathan Warnberg Slowly
Ryan Martin Matrix version of Szemerédi's regularity lemma
T, Apr 16 Colloquium: Chelsea Walton, Massachusetts Institute of Technology An introduction to noncommutative invariant theory
 F, Apr 19 Colloquium: Ron Taylor, Berry College Implementations of active learning in the mathematics classroom
T, Apr 23 Colloquium: Dean Beate Schmittmann (Physics, ISU) First attempts at characterizing interacting networks
Th, Apr 25 Colloquium: Nate Dean, Texas State University Some edge length problems and applications
Sa Apr 27-
Su, Apr 28
AMS Central Sectional Meeting
Erdős Lecture (Endre Szemerédi)
· Algebraic and Geometric Combinatorics
· Computability and Complexity in Discrete and Continuous Worlds
· Discrete Methods and Models in Mathematical Biology
· Extremal Combinatorics
· Generalizations of Nonnegative Matrices and Their Sign Patterns
· Graphs, Hypergraphs and Counting
· Logic and Algebraic Logic
· Zero Forcing, Maximum Nullity/Minimum Rank and Colin de Verdiere Graph Parameters
Apr 30 Jozef Skokan, London School of Economics Maximum planar subgraphs in dense graphs

2012 Fall

Date Speaker Title
Aug 21 Organizational Meeting
 Aug 28 Steve Butler Counting juggling patterns
Sep 04 Craig Erickson Sign patterns that allow strong eventual nonnegativity
Sep 11 Michael Young Reciprocity of weak chromatic polynomials of mixed graphs
Sep 18 Orientation for MIGHTY session chairs
Th, Sep 20 Colloquium: Fan Chung Graham, UCSD Semigroup spectral theory and graph coloring games
F, Sep 21 F. Wendell Miller Lecture: Ron Graham, UCSD Computers and mathematics: Problems and prospects
Sa, Sep 22
MIGHTY LIII conference: Persi Diaconis, Stanford Graph coloring and the birthday problem
Sep 25 H. Tracy Hall, Novatek and Brigham Young University Simplex coverings by lattice translations
Oct 02 Maria Axenovich Twin sets in sequences and graphs
Oct 09 Roger Maddux Arrow's impossibility theorem for incomplete relations
Oct 16
Oct 23 Ryan Martin Posets and graphs
Oct 30
Nov 06 Nathan Warnberg Coloring stuff fast
Nov 13 Steven Osborne  
Nov 19-23: Thanksgiving Break, No Seminar
Nov 27 Craig Erickson On sign patterns that require eventual exponential nonnegativity
 M, Dec 03 Ryan Martin On a quadratic programming problem for graph theory

2012 Spring

Date

Speaker

Title

Jan 10

James Cummings, Carnegie Mellon University

The density of monochromatic triangles in 3-colourings of the edges of Kn

Jan 17

Tracy McKay

How far can you get from an induced K2,t-free graph?

Jan 24

Jason Smith

An introduction to induced saturation number: A job talk geared toward undergraduates

Jan 31

Michelle Lastrina

List-coloring extensions on planar graphs

Feb 06

ECpE Faculty Seminar: Ryan Martin

Vertex identifying codes and random graphs

Feb 07

Ryan Martin

More on vertex identifying codes and related parameters

Feb 20

Colloquium: Zhisheng Shuai, University of Victoria Dynamical Systems on Networks and their Applications to Ecology and Epidemiology

Mar 02

Colloquium: Alan Veliz-Cuba, University of Nebraska -Lincoln

An Algebraic Approach to Reverse Engineering Discrete and Continuous Models of Biological Systems

Mar 06

Steve Butler

Avoiding constellations

Mar 12-16: Spring Break, No Seminar

Mar 25

Math Club talk: Ryan Martin

The Small World Problem: Six Degrees of Graph Theory

Apr 03

Paul Horn, Harvard University

Isomorphic subgraphs in graphs and hypergraphs

Apr 10

Abbas Hakim, CAMS (Center for Advanced Mathematical Sciences)

De Bruijn sequences can all be greedy

Apr 17

Chad Vidden

Snake oils on a β0, β1 plane

Apr 24

Discussion


2011 Fall

Date

Speaker

Title

Aug 23

Organizational Meeting

Aug 30

Colloquium: Steve Butler (ISU)

Generalizations of Apollonian circle packings

Sep 06

Steve Butler

Constructing induced universal graphs for graphs with bounded degrees

Sep 06

Math Club talk: Steve Butler

Fibonacci meets Erdõs-Ko-Rado

Sep 13

Leslie Hogben

Propagation time for zero forcing on a graph

Sep 20

Steven Osborne/Nathan Warnberg

Computing positive semidefinite mnimum rank for small graphs

Sep 27

Oktay Olmez

A construction for vertex transitive directed strongly regular graphs

Sep 27

Colloquium: Nic Lanchier,
Arizona State

Two-strategy games on the lattice

Oct 04

Craig Erickson

Positive semidefinite maximum nullity is equal to positive semidefinite zero forcing number for partial 2-trees

Devin Bickner

Binary normal network space is connected

Oct 11

Derrick Stolee, University of Nebraska - Lincoln

Searching for uniquely saturated and strongly regular graphs using coupled augmentations

Oct 18

Tracy Hall, Brigham Young University

The greedegree theorem for faithful orthogonal graph representations

Nov 01

Michelle Lastrina

{2,2}-extendability of planar graphs: Closing the gap on a conjecture of J.P. Hutchinson

Nov 08

Ryan Martin

Fractional version of the multipartite Hajnal-Szemerédi theorem

Nov 15

Geoff Tims

On Haemers' invariant

Nov 21-25: Thanksgiving Break, No Seminar

Nov 29

Lucas Kramer

Counting using flag algebras

Dec 06

Michael Young

Sum List Coloring Graphs Composed of Cycles


2011 Spring

Date

Speaker

Title

Jan 11

Organizational Meeting

Jan 18

Ryan Martin

Using localization to compute edit distance I

Jan 25

Ryan Martin

Using localization to compute edit distance II

Feb 01

Jason Smith

Saturation number of t disjoint copies of Kp

Feb 08

Travis Peters

Positive semidefinite zero forcing

Feb 15

Alex Roitershtein

Spider's random walk: on the intersection of probability and linear algebra

Feb 22

Oktay Olmez

Directed strongly regular graphs obtained from tactical configurations

Mar 01

Tyler Seacrest,
University of Nebraska-Lincoln

Degree Sequences, Bisections, and Edge-Disjoint 1-factors

Mar 08

Lale Ozkahya

Unavoidable subhypergraphs: a-clusters

W, Mar 09

Colloquium: Steven Butler, UCLA

Constructing cospectral graphs for the normalized Laplacian

Mar 14-18: Spring Break, No Seminar

Mar 22

Steve Willson

Reconstructing the parameters of a network from its tree-average distances

Mar 29

Michelle Lastrina

An introduction to sum-list-coloring and sc-greedy graphs

Apr 05

Jozef Skokan, London School of Economics

Ramsey-type problems on non-complete graphs

Apr 12

Jason Ekstrand, Craig Erickson, Diana Hay, Jolie Roat

On positive semidefinite maximum nullity and positive semidefinite zero forcing number of partial 2-trees

Apr 17

Ryan Johnson, Steven Osborne, Travis Peters

Positive semidefinite zero forcing and some of its properties

Apr 26

Nicole Kingsley, Arianne Ross, Nathan Warnberg

And you thought regular zero forcing was cool!

T, May 03

Daniel Burgarth, Imperial College London
Simone Severini, University College London

Zero forcing/graph propagation and quantum control

T, May 03

Colloquium: Andrew Beveridge, Macalester College

The visibility number for planar digraphs and tournaments


2010 Fall

Date

Speaker

Title

Aug 24

Organizational Meeting

Aug 31

Leslie Hogben

Matrices that eventually have a property

Sep 07

Lale Ozkahya

On Even-cycle-free Subgraphs of the Hypercube

Sep 14

Oktay Olmez

Construction Of Directed Strongly Regular Graphs Using Finite Incidence Structures

Sep 21

Michelle Lastrina

On extending a precoloring of a special set of vertices to a 5-list-coloring of a planar graph

Sep 28

Jason Smith

A Friendly Introduction to Saturation Number

Oct 12

Michael Young

Excessive Factorization Results 

Oct 19

Maria Axenovich

How many distinct distances are determined by n points in the plane? 

Oct 26

Craig Erickson

Potentially eventually exponentially positive sign patterns

Nov 02

Darren Row

Graphs, Matrices, and Forcing Zeros

Nov 09

Devin Bickner

The Cluster Containment Problem

Nov 16

Steve Butler, UCLA

Hat guessing games and orienting hypercubes

Nov 30

Sung-Yell Song

Classification and characterization problems of association schemes

Dec 07

Tracy McKay

Colored Regularity Graph Constructions for the Edit Distance Function of Forb(K_{2,t})


2010 Spring

Date

Speaker

Title

Jan 12

Organizational Meeting -- Note: The meeting is in Carver 385

Jan 19

Ryan Martin Beauty is rare: The Hoffman-Singleton Theorem
Jan 26 Aaron Sterling, CS Memory Consistency Conditions for Self-Assembly Programming
Feb 02 Jacob Manske Bukh II: A special case of the conjecture
Feb 09 Brendon Stanton Battle of the Codes:  Error Correcting vs. Vertex Identifying
Feb 16 Leslie Hogben Minimum rank of full sign patterns and applications to communication complexity
Feb 23 Tracy McKay The Erdős-Faber-Lovász Conjecture and Kahn's Asymptotic Result
Mar 02 Sung-Yell Song Distance-regular graphs and algebraic coding theory: an introduction to Delsarte's work*
Mar 09 Michelle Lastrina Choosability versus chromaticity: the plane unit distance graph has a 2-chromatic subgraph of infinite list-chromatic number
Mar 23 Ryan Martin The entropy method and the number of independent sets in a regular graph
Mar 30 Stephen Willson Relationships between phylogenetic networks
 Apr 06 Devin Bickner Phylogenetic networks - The tree containment problem
Apr 13 Ryan Martin Entropy and Counting
Apr 20 Jason Smith Discharging to improve injective chromatic number bounds
Apr 27 Stephen Willson Simplifying phylogenetic networks with bottlenecks

2009 Fall

Date

Speaker

Title

Aug 25

Organizational Meeting

Sep 01

Ryan Martin

Tiling on multipartite graphs
Sep 08 Luz De Alba Acyclic and unicyclic graphs whose minimum skew rank is equal to the minimum skew rank of a diametrical path
Sep 15 Colloquium by Leslie Hogben replaces seminar: "Sign patterns that require eventual positivity or require eventual nonnegativity"
Sep 22 Craig Erickson On Nilpotence Indices of Sign Patterns
Sep 29 Colloquium by Jerrold Griggs replaces seminar: "Venn diagrams, necklaces, and chain decompositions of posets"
Oct 06 JiHyeok Choi On Combinatorial Discrepancy
Oct 13 Colloquium by H. Tracy Hall replaces seminar "What is quantum computation?"
Oct 20 Tracy McKay

CRGs, p-core CRGS, and a strategy for finding d*

Oct 27 Jake Manske A proof from the Bukh: a proof of a special case of an analogue of the Erdos-Stone theorem for posets
Nov 03 Brendon Stanton Vertex identifying codes on infinite grids
Nov 10 Michelle Lastrina List coloring on planar graphs: Extending a precoloring of two vertices
Nov 17 Darren Row Cut-vertex reduction for zero forcing number
Dec 01 Jason Smith Coloring 101: A different color from 110, 000 or 011
Dec 08 Maria Axenovich On dense families of sets without fixed sub-families

2009 Spring

Date

Speaker

Title

Jan 27

Roger Maddux


Feb 03

Feb 10

Salah A. Aly

Classical and quantum LDPC codes constructed from elements of Finite fields and finite geometries.

Feb 17

Jake Manske

Frolicking in a butterfly-free meadow: on the largest set family without $A \cup B \subset C \cap D$

Feb 24

Darren Row

An introduction to number coloring: Some generalizations of Schur's Theorem

Mar 03

Michelle Lastrina

Planar 5-list coloring: Non-extendability at distance 4

Mar 10

Maria Axenovich

On list-coloring extensions

Mar 24

Luke Paben

Edge-Colorings of Simple, Complete Graphs which Forbid "Rainbow" Cycles

Mar 31

Ryan Martin

On Avoider-Enforcer games

Apr 07

Laura DeLoss

Determining minimum skew rank of matrices described by a graph: results using cut-vertex reduction on coronas

Apr 14

Ryan Martin

On the minimum rank of graphs

Apr 21

Jason Grout

Ultraconnected graphs and partial matrix completion problems

Apr 28

JiHyeok Choi

Anti-Ramsey number for cycles


2008 Fall

Date

Speaker

Title

Sep 02

Olga Pryporova


Sep 09 Colloquium by Benny Sudakov, UCLA

Sep 16

Jake Manske

Sunshine, Lollipops, and Rainbow Subposets of the Boolean Lattice

Sep 23

Jake Manske

It's my poset and I'll cry if I want to

Sep 30

Jason Smith

Conjunctive Normal Form and Its Representational Power

Oct 07

Maria Axenovich

On voting games and 3-chromatic hypergraphs

Oct 14

Jeremy Alm

The logical roots of Ramsey's theorem

Oct 21

Ji-Hyeok Choi

Some mixed anti-Ramsey numbers on cycles

Oct 28

Tracy McKay

W. G. Brown's Construction for Graphs That Do Not Contain a Thomsen Graph

Nov 04

Ryan Martin

The expander mixing lemma

Nov 11

Luz DeAlba

Minimum Skew Rank and the diameter of a graph.

Nov 18

Rana Mikkelson


Dec 02

Jason Grout

The minimum rank problem for powers of graphs.

Dec 09

Michelle Lastrina



2008 Spring

Date

Speaker

Title

Jan 22

Luz De Alba

Matrix Completion Problems

Jan 29

Luz De Alba

The Q-matrix Completion Problems

Feb 05

Maria Axenovich

On transversals of longest paths in graphs.

Feb 12

Jack Lutz

Combinatorial Aspects of Nanoscale Self-Assembly

Feb 19

Ryan Martin

The Vertex Ramsey Problem.

Feb 26

Jason Grout


Mar 04

Jake Manske

Monochromatic subsets of the integer grid

Mar 11

Colloquium by Hemanshu Kaul, Illinois Inst. of Tech.

Apr 01

Leslie Hogben

Minimum Rank of Not Necessarily Symmetric Matrix Patterns

Apr 08

Rana Mikkelson and Kaela Rasmussen

Universally optimal matrices and field independence of the minimum rank of a graph

Apr 15

Tracy McKay, Jason Smith

Software for computation of Minimum Rank

Apr 22

Laura DeLoss, Geoff Tims

The Graph Complement Conjecture for Minimum Rank

Apr 29

Olga Pryporova

Diagonal and D-convergence of matrices


2007 Fall

Date

Speaker

Title

Aug 28

Jason Grout

The minimum rank problem over finite fields:
or "Yet another problem that projective geometry answers!"

Sep 04

Sep 11

Alex Roitershtein

Random strategies for the Robin Hood game

Sep 18

Leslie Hogben

Minimum rank of nonsymmetric matrices described by a digraph

Sep 25

 Sep 27

(Th) DCS Lecture by F.R. (Buck) McMorris, Illinois Inst. of Tech.

Oct 02

Ryan Martin

Edit distance in graphs: Colored regularity graphs

Oct 02

DCS lecture by Leif Jorgensen

Oct 09

Colloquium by Chris Godsil, U. of Waterloo

Oct 11

(Th) Miller Lecture by Daniel Gusfield

Oct 16

Chad Brewbaker

An Introduction to Computational Genetics for the Graph Theorist

Oct 23

Olga Pryporova

Qualitative Convergence of Matrices

Oct 30

Leslie Hogben

Teaching Linear Algebra: Technology and Resources

Nov 07

(W) Graduate student seminar by Leslie Hogben

Nov 14

(W) Graduate student seminar by Ryan Martin

Nov 27

Rana Mikkelson

Minimum rank of graphs with loops

Dec 04

Ryan Martin

Forbidden subgraphs of Unit Disk Graphs


2007 Spring

Date

Speaker

Title

Jan 09 Colloquium by Sang-Gu Lee, Sung Kyung Kwon University
Jan 16 Y. T. Poon Unitary orbit, matrix completion and generalized numerical ranges
Jan 23 Y. T. Poon Sum and difference of unitary orbits: Eigenvalues
Jan 30 Y. T. Poon Sum and difference of unitary orbits: Inertia
Feb 06 Ryan Martin Beauty is rare: The Hoffman-Singleton theorem
Feb 13 Maria Axenovich Saturation of cycles
Feb 20 Jeremy Alm and Jake Manske A probabilistic nightmare: Constructing the world's worst graph (sort of)
Feb 27 Leslie Hogben Introduction to minimum rank and zero forcing sets
Feb 27 Colloquium by Ales Drapal, Charles U./U. of Wisconsin
Mar 06 Jake Manske The boogie woogie bugle boy with Property B
Mar 20 Luz DeAlba Minimum rank of powers of some special graphs
Mar 23 (F) Colloquium by Jason Grout, Brigham Young U.
Mar 26 (M)  C,A,NT Seminar by William Gasarch (U. of Minnesota, Duluth)
Mar 27 Dan Cranston, UIUC

Coloring and List-coloring of Graphs

Mar 27 Miller lecture by Neal Koblitz, U. of Washington
Apr 03 Alex Burstein Dumont permutations of the third kind
Apr 05 (Th) Colloquium by F.R. McMorris, Illinois Inst. of Tech.
Apr 10 Leslie Hogben Minimum rank of symmetric matrices of a graph
Apr 17 Ryan Martin Some intriguing open problems regarding positional games
Apr 24 Maria Axenovich Vertex-Ramsey numbers

2006 Fall

Date

Speaker

Title

Aug 29 Leslie Hogben Introduction to Combinatorial Matrix Theory
Sep 05 Alex Burstein
On some properties of permutation tableaux
Sep 12 Colloquium by Alexander Kostochka, UIUC
Sep 19 Ryan Martin
Recent results on packing problems in multipartite graphs
Sep 26 Michelle Lastrina An Overview of k-Harold and k-Audrey, the Ihara Zeta Function, and Seidel Switching
Oct 03
Jeremy Alm
Constructing the World's Worst Graph: a nightmare
Oct 10
Maria Axenovich
Edge-colorings avoiding rainbow and monochromatic subgraphs
Oct 17
Rich McBride
The Convex Hull of Signed Degree Sequences
Oct 24 Jake Manske
Erdõs the Calvinist: Predestined Subgraphs
Oct 24
Colloquium by Sung-Yell Song, ISU
Oct 31
Eric Hansen, Tracy McKay, Andrew Regensheid
Introduction to Stegonography and Steganalysis: Embedding Schemes and Attacks
Nov 07 Ryan Martin Generalized tic-tac-toe: Introduction to Positional Games and probabilistic
intuition
Nov 14
Ryan Martin
The diameter game on graphs
Nov 28 Olga Pryporova
Introduction to Matrix Stability, D-stability, and D-convergence
Dec 05 Rana Mikkelson
Introduction to Minimum Rank Problems

2006 Spring

Date

Speaker

Title

Jan 23 Irvin R. Hentzel
Finite Division Rings
Jan 30 Richard Kramer
Definability in Geometry and the Product Rule for Derivations, Part I
Feb 06 Richard Kramer
Definability in Geometry and the Product Rule for Derivations, Part II
Feb 13 Leslie Hogben Introduction to Matrix Completions
Feb 20 Luz DeAlba The Q-matrix Completion Problem
Feb 27 Y. T. Poon Product of differences of complex numbers and the determinantal conjecture.
Mar 6 Chi-Kwong Li, College of William and Mary
Spectrum preserving maps
Mar 20 Ryan Martin On the Editing Distance in Graphs
Mar 27 Colloquium by Fan Chung, UCSD
Apr 03 Leslie Hogben A new graph parameter for minimum rank
Apr 10 Steve Willson Reconstructing phylogenetic networks from distances between leaves
Apr 17 Ryan Martin Introduction to Expander Graphs
Apr 24 Rana Mikkelson, Olga Pryporova
Spectrally Arbitrary Sign Pattens

2005 Fall

Date

Speaker

Title

Aug 30 Sung-Yell Song Characterizations of Strongly Regular Graphs
Sep 06 Sung-Yell Song Characterizations of Strongly Regular Graphs: Bose-Mesner Algebras
Sep 13 Leslie Hogben and Rana Mikkelson Rational Realization of Maximum Eigenvalue Multiplicity of Symmetric Tree Sign Patterns
Sep 20 Sung-Yell Song Characterizations of Strongly Regular Graphs
Sep 27 Jozsef Balogh On $k$--sets, convex quadrilaterals, and the rectilinear crossing number of $K_n$
Oct 04 Maria Axenovich On graphs with small number of subgraphs with distinct sizes
Oct 11
Oct 18 Bhaba Sarma Energy of Graphs
Oct 25 Ryan Martin An application of Szemerédi’s Regularity Lemma
Nov 01
Nov 08
Nov 15 Doug Ray, Jake Manske The NFL superfan problem
Nov 29 Alex Burstein Patience Sorting and Barred Pattern Avoidance