Dr. Callahan is a mathematics associate professor, Math Club sponsor and advisor, and McNair Scholars Program STEM faculty advisor.

Since joining St. Edward's University in 2009, Dr. Callahan has mentored sixteen research students and taught Applied Statistics, Linear Algebra, Calculus I, II, and III, Calculus I Lab, Precalculus, Mathematics for Liberal Arts, Science Seminar, and Science/Mathematics First-Year Seminar. He won the Mathematical Association of America (MAA) Texas Section Ron Barnes Distinguished Service to Students Award in 2018, the School of Natural Sciences Dean’s Excellence in Teaching Award in 2018, the Dean’s Faculty Excellence Award for Research in the School of Natural Sciences in 2015, and the School of Natural Sciences Distinguished Teaching Award in 2014 and was named a finalist for the University Distinguished Teaching Award in 2015. Every year he coordinates trips for students to present their research at regional and national math conferences such as the MAA Texas Section Meeting, Texas Undergraduate Mathematics Conference, Joint Mathematics Meetings, and MAA MathFest.

Education

  • Ph.D. in Mathematics at The University of Texas at Austin, 2009
  • B.S. in Mathematics at The University of Texas at Austin, 2002

Achievement & Involvement

Honors and Awards

2018, Ron Barnes Distinguished Service to Students Award, Mathematical Association of America Texas Section
2018, School of Natural Sciences Dean’s Excellence in Teaching Award, St. Edward's University
2015, Dean’s Faculty Excellence Award for Research in the School of Natural Sciences, St. Edward's University
2015, University Distinguished Teaching Award Finalist, St. Edward's University
2014, Presidential Excellence Research Grant, St. Edward's University
2014, School of Natural Sciences Distinguished Teaching Award, St. Edward's University
2011, MAA Texas Section Project NExT Fellowship
2010, MAA National Project NExT Fellowship
2007, Department of Mathematics Outstanding Teaching Award, The University of Texas at Austin
2004, Frank Gerth III Teaching Excellence Award, The University of Texas at Austin

Community Service

Dawson Neighborhood Association and Planning Contact Team, KUT Public Radio sustaining member, City of Austin Water Conservation Block Leader, named one of "sixty most qualified applicants" for Independent Citizens Redistricting Commission of Austin’s 10-One Redistricting Initiative, helped develop Austin’s first Annual Performance Report and "Dashboard," CityWorks Academy '09

Organizations, Boards and Memberships

American Mathematical Society (AMS), Mathematical Association of America (MAA), MAA Texas Section, MAA Special Interest Groups on Inquiry-Based Learning, Quantitative Literacy, and Undergraduate Research (SIGMAA IBL, QL, and UR), Academy of Inquiry Based Learning (AIBL), Council on Undergraduate Research (CUR)

Conferences

MAA Texas Section Meeting, MAA MathFest, MAA and AMS Joint Mathematics Meetings, Texas Undergraduate Mathematics Conference, Geometry of Redistricting Workshop, Texas Undergraduate Topology and Geometry Conference, Legacy of R. L. Moore Conference, Lilly Conference on College and University Teaching and Learning, St. Edward's University Teaching Symposium: A Conference on College Teaching, Texas Hispanic Serving Institutions Consortium Spring Conference, U.S. News STEM Solutions National Conference

 

 

External Grants

Active Grants

Co-Principal Investigator (co-PI), National Science Foundation (NSF) Improving Undergraduate STEM Education (IUSE) grant “SEU Living Learning Community/Active Learning (LLCAL) Project,” five years, $1.6 million, August 2015 to present

Publications & Articles

Publications

  • Knots, Molecules, and the Universe: An Introduction to Topology (with Erica Flapan et al.). American Mathematical Society (AMS), Providence, RI: 386 pages, 2016.
  • The Arithmetic and Geometry of Two-Generator Kleinian Groups. ProQuest/UMI, 2010.

Articles

  • Solving Scramble Squares Puzzles with Repetitions (with Maria Mota). Involve: a Journal of Mathematics, 12(2): 343-349, 2019.
  • Aesthetics in a Mathematics for Liberal Arts Project (with Carol Gee). Journal of Humanistic Mathematics, 7(1): 139-146, 2017.
  • Assessing Online Homework in First-Semester Calculus. PRIMUS: Problems, Resources, and Issues in Mathematics Undergraduate Studies, 26(6): 545-556, 2016.
  • Markov Chains to Compute Expected Game Lengths of “Chutes and Ladders” (with Harris Greenwood). Pi Mu Epsilon Journal, 14(4): 243-250, 2016.
  • Analysis of a Coupled, n-Patch Population Model with Density Dependence (with Richard Rebarber et al.). International Journal of Difference Equations, 10(2): 137-159, 2015.
  • Denominators and Differences of Boundary Slopes for (1,1)-Knots. Boletín de la Sociedad Matemática Mexicana, 21(2): 275-287, 2015.
  • Assessing Online Homework in Mathematics for Liberal Arts (with Carol Gee). Lilly Conference Proceedings on College and University Teaching and Learning, Austin, TX, 5-8, 2014.
  • Conjugate Generators of Knot and Link Groups. Journal of Knot Theory and Its Ramifications, 19(7): 905-916, 2010.
  • Jørgensen Number and Arithmeticity. Conformal Geometry and Dynamics, 13: 160-186, 2009.
  • Haiku in “Math in Seventeen Syllables: A Folder of Mathematical Haiku.” Journal of Humanistic Mathematics, 8(1): 441-472, 2018.
  • Explanation in "UT Math Professor Luis Caffarelli Wins Wolf Prize For Something That Has To Be Explained To Us." Austinist, Jan. 26, 2012.

Presentations

  • Analysis of a Length-Structured Model for Fish. MAA Texas Section Meeting, El Centro College, April 6, 2018.
  • Road to and Careers in Academia. McNair Scholars Program, SEU, Nov. 17, 2017.
  • Active Learning and Academic Support in Calculus I (with Carly Badke). School of Natural Sciences Faculty Learning Community, SEU, Sept. 20, 2017.
  • Assessing a Course Design to Reinforce Active Learning and Academic Support (with Carly Badke). Teaching Symposium: A Conference on College Teaching, SEU, Aug. 24, 2017.
  • General Education Big Tent Event: How to Make Your Course Part of the New Gen Ed (with Dan Glenn et al.). Teaching Symposium: A Conference on College Teaching, SEU, Aug. 24, 2017.
  • Analysis of a Coupled, n-Patch Population Model with Density Dependence. ApREUF: Applied Research Experience for Undergraduate Faculty AMS Special Session, Joint Mathematics Meetings, Atlanta, Jan. 6, 2017.
  • Chutes, Ladders, and Markov Chains. RE(UF)search on Graphs and Matrices AMS Special Session, Joint Mathematics Meetings, Atlanta, GA, Jan. 5, 2017.
  • Research Support Networks. Joint Mathematics Meetings, Atlanta, GA, Jan. 4, 2017.
  • Mid-semester Student Feedback and Learning through Active Questioning. Teaching Symposium: A Conference on College Teaching, SEU, Aug. 25, 2016.
  • Living-Learning Community/Active Learning (LLCAL) NSF Project (with Richard Kopec et al.). Teaching Symposium: A Conference on College Teaching, SEU, Aug. 25, 2016.
  • Analysis of a Coupled, n-Patch Population Model with Density Dependence. Mathematical Association of America (MAA) Texas Section Meeting, Stephen F. Austin State University, April 1, 2016.
  • Faculty Positions at Undergraduate Institutions. College of Natural Sciences Grad Student and Postdoc Professional Development Seminar, UT-Austin, June 11, 2015.
  • Chutes, Ladders, and Markov Chains. MAA Texas Section Meeting, San Antonio, TX, April 10, 2015.
  • Perspectives & Suggestions on General Education Assessment (with David Blair et al.). Teaching Symposium: A Conference on College Teaching, St. Edward's University, Aug. 21, 2014.
  • Assessing Online Homework in Calculus and Mathematics for Liberal Arts. MAA Texas Section Meeting, Texas A&M International University, April 4, 2014.
  • Assessing Online Homework in Calculus and Mathematics for Liberal Arts (with Carol Gee). Lilly Conference on College and University Teaching and Learning, Austin, TX, Jan. 3, 2014.
  • Careers in Academia. Graduate Professional Development Week, The University of Texas at Austin, Sept. 10, 2013.
  • Online Homework in the General Education Mathematics Courses (with Carol Gee et al.). Teaching Symposium: A Conference on College Teaching, St. Edward's University, Aug. 22, 2013.
  • Inquiry-Based Learning Projects in an Applied Statistics Course. 16th Annual Legacy of R. L. Moore Conference, Austin, TX, June 13, 2013.
  • Quantitative Literacy and World Societies. World History Association of Texas Conference: Global Identities in the Digital Age and Phi Alpha Theta Honor Society Central/West Texas Regional Conference, SEU, March 2, 2013.
  • Measuring Rope: How Open Should Open-Ended Projects Be? Teaching Showcase: A Conference on College Teaching, SEU, Aug. 25, 2011.
  • General Education in the Global Century: The SEU Project Team (with Richard Kopec et al.). Teaching Showcase: A Conference on College Teaching, SEU, Aug. 25, 2011.