Profile for Nathan Warnberg

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Nathan Warnberg

Associate Professor
Mathematics & Statistics
University of Wisconsin-La Crosse

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Specialty area(s)

Graph Theory, Ramsey Theory, Combinatorics

Brief biography

I grew up in Wisconsin (Barron, WI), am a graduate of the UW system (UW-Platteville), and after a graduate career at Iowa State University I am glad to be back in my home state.

My current mathematics research interests are the interplay between graph theory and matrix theory, a.k.a. combinatorial matrix theory.  I also really enjoy avoiding rainbows in the research area of Anti-Ramsey Theory.

I am interested in learning theory and applying the theory to my classrooms. This leads to my passion about helping my students become independent learners. So, if you are in one of my classrooms do not be surprised if you end up participating in some different activities!

Current courses at UWL

Math 150 (College Algebra)
Math 299 (Tutor Training)
Math 317 (Graph Theory)


Ph.D. Mathematics (Physics minor), Iowa State Univesity, 2014.

B.S. Mathematics (Economics minor), University of Wisconsin-Platteville, 2008.


Teaching history

MTH 150 (College Algebra), MTH 175 (Business Calculus), MTH 207 (Calculus I), MTH 208 (Calculus II), MTH 309 (Linear Algebra), MTH 310 (Calculus III), MTH 317 (Graph Theory), Math 395 (Independent Study), MTH 495 (Undergraduate Research)

Professional history

Assistant Professor of Mathematics, University of Wisconsin-La Crosse, August 2014 - Present.

Graduate Teaching Assistant, Iowa State University, June 2009 - May 2014.

Lead Teaching Assistant, Iowa State University, May 2012 - May 2013.

Research and publishing


  • Directionality of the Equals Sign (with T. Das and W. George), PRIMUS, 2019.
  • Anti-van der Waerden Numbers on Graph Products (with H. Rehm and A. Schulte), Australasian Journal of Combinatorics, 73(3), 2019.
  • Zero forcing propagation time on oriented graphs (with A. Berliner et al.), Discrete Applied Math, 224, 2017.
  • Rainbow arithmetic progression (with S. Butler et al.), Journal of Combinatorics, 7(4), 2016.
  • Positive semidefinite propagation time. Discrete Applied Math, 198, 2016.
  • Path cover number, maximum nullity, and zero forcing number of oriented graphs and other simple digraphs (with A. Berliner et al.). Involve, a Journal of Mathematics, 8(1), 2015

  • Computing positive semidefinite minimum rank for small graphs (with S. Osborne). Involve, a Journal of Mathematics, 7(5), 2014.

  • Positive semidefinite zero forcing (with J. Ekstrand et al.). Linear Algebra and Applications, 439(7), 2013.

Papers Under Review

  • Rainbow Numbers of Z_p and Z_(pq) (K. Ansaldi et al.).
  • Anti-van der Waerden Numbers on Graphs (Z. Berikkyzy et al.).
  • Properties of a q-analogue of zero forcing (S. Butler et al.).
  • Anti-Schur numbers for x_1 + x_2 + ... + x_(k-1) = x_k in [n] (K. Fallon et al.).



Nathan Warnberg, Mathematics & Statistics, co-authored the article "Anti-van der Waerden Numbers on Graphs" in Graphs and Combinatorics published on Monday, July 25 by Springer Nature. The paper extends the idea of finding rainbow structures in the positive integers and the integers modulo n to finding rainbow structures in graphs.

Submitted on: July 25, 2022



Nathan Warnberg, Mathematics & Statistics, co-authored the article "On leaky forcing and resilience" in Discrete Applied Mathematics and was accepted for publication by Elsevier. Leaky forcing helps determine the robustness of an information network by assuming that some nodes in the network do not pass along the information.

Submitted on: Nov. 4, 2021



Eugenia Turov, Chemistry & Biochemistry; and Tushar Das, Whitney George and Nathan Warnberg, all Mathematics & Statistics; designed an anti-racist education workshop for "the purpose of building a Community of Anti-Racist Educators". In addition, Whitney George and Eugenia Turov co-faciliated the weeklong workshop. The workshop was a resounding success as noted by one participant leaving with 'profound insights about their personal struggles with internalized white-supremacy and how it shows up in their classrooms.'

Submitted on: Aug. 30, 2021



Nathan Warnberg, Mathematics & Statistics, co-authored the article "Properties of a q-Analogue of Zero Forcing" in Graphs and Combinatorics and was accepted for publication by Springer. The genesis of this paper was from the American Institute of Mathematics workshop: Zero Forcing and its Applications.

Submitted on: Aug. 5, 2020



Nathan Warnberg, Mathematics & Statistics, co-authored the article "Rainbow Numbers of Z_n for a_1x_1+a_2x_2+a_3x_3 = b" in INTEGERS: Electronic Journal of Combinatorial Number Theory published on July 24 by Colgate University, Charles University, and DIMATIA.

Submitted on: July 31, 2020