Dr. Stefan Ovidiu Tohaneanu


Department of Mathematics
University of Idaho
875 Perimeter Drive MS 1103, Moscow, ID 83844-1103
Phone: (208) 885-6234
tohaneanu@uidaho.edu

Employment

2019-present: Associate Professor, University of Idaho
2013-2019: Assistant Professor, University of Idaho
2010-2013: Postdoctoral Fellow and Assistant Professor, The University of Western Ontario (Advisor Dr. Graham Denham)
2007-2010: Visiting Assistant Professor, University of Cincinnati
2002-2007: Graduate Teaching Assistant, Texas A&M University

Education
Ph.D., Mathematics, Texas A&M University, 2007 (Advisor Dr. Hal Schenck)
M.S., Mathematics (Analysis), University of Bucharest, 2001
M.S., Mathematics (Algebra), University of Bucharest, 1999
B.S., Mathematics, University of Bucharest, 1997

MATH CLUB

USEFUL LINKS FOR MATH MAJOR UNDERGRADUATE STUDENTS

Teaching

Students, please check blackboard for detailed information.

Spring 2024: MATH 556: Groups and Fields II, and MATH 310: Ordinary Differential Equations

Fall 2023: MATH 555: Groups and Fields I, and MATH 415: Cryptography

Spring 2023: MATH 275: Calculus III, and MATH 330: Linear Algebra

Spring 2022: MATH 556: Groups and Fields II, and MATH 330: Linear Algebra

Fall 2021: MATH 555: Groups and Fields I, and MATH 415: Cryptography

Spring 2021: MATH 462: Abstract Algebra II, and MATH 330: Linear Algebra

Fall 2020: MATH 461: Abstract Algebra I, and MATH 430: Advanced Linear Algebra

Spring 2020: MATH 376: Discrete Math II, and MATH 330: Linear Algebra

Fall 2019: MATH 176: Discrete Math I, and MATH 415: Cryptography

Spring 2019: MATH 275: Calculus III, and course coordinator for MATH 175: Calculus II

Fall 2018: MATH 176: Discrete Math I, and MATH 415: Cryptography

Spring 2018: MATH 420: Complex Variables, and MATH 176: Discrete Math I

Fall 2017: MATH 461: Abstract Algebra I, and MATH 415: Cryptography

Spring 2017: MATH 558: Intro to Algebraic Geometry, and MATH 176: Discrete Math I

Fall 2016: MATH 557: Ring Theory, and MATH 330: Linear Algebra

Summer 2016 – II: MATH 310: Ordinary Differential Equations

Spring 2016: MATH 330: Linear Algebra, and MATH 556: Groups and Fields II

Fall 2015: MATH 170: Calculus I (entire in-campus course), and MATH 555: Groups and Fields I

Summer 2015: MATH 310 (both sections): Ordinary Differential Equations

Spring 2015: MATH 310: Ordinary Differential Equations

Fall 2014: MATH 176: Discrete Math I, and MATH 275: Calculus III

Spring 2014: MATH 376: Discrete Math II

Fall 2013: MATH 330: Linear Algebra

Semesters I have been teaching MATH 176 (EO): Discrete Math I – Engineering Outreach: Spring 2023, Fall 2021, Fall 2020, Summer 2020, Spring 2020, Fall 2019, Spring 2019, Fall 2018, Summer 2018.

Research
My research interests are in Commutative Algebra with applications to Combinatorics, Discrete Geometry, Algebraic Geometry, Coding Theory or Spline Approximation. Please click this link for a detailed CV. Stuff about me and my research can be also found on Google Scholar and Research Gate.

My book titled “Commutative Algebra Methods for Coding Theory” has been accepted for publication by De Gruyter.

This is the list of my publications. Most of the articles are hyperlinked to their arXiv old versions (hence may contain errors and the exposition is outdated). For the published updated latest versions of the articles, please check the journals’ websites.

  1. The minimum distance and special fibers

Submitted; a version is available at arXiv: 2311.03688.

  1. The Geometry of the Minimum Distance (with J. Pawlina)

Submitted; a version is available at arXiv: 2310.00102.

  1. On the Jacobian ideal of an almost generic hyperplane arrangement (with R. Burity and A. Simis)

Proc. Amer. Math. Soc. 150 (2022), 4259-4276.

  1. Logarithmic derivations associated to line arrangements (with R. Burity)

J. Algebra 581 (2021), 327-352.

  1. Homological properties of ideals generated by fold products of linear forms (with R. Burity and Yu Xie)

Michigan Math. J. (2023), advanced publication, DOI: 10.1307/mmj/20216173.

  1. On Geramita-Harbourne-Migliore conjecture (with Yu Xie)

Trans. Amer. Math. Soc. 374 (2021), 4059-4073.

  1. On some ideals with linear free resolution

Unpublished; a version is available at arXiv: 1906.02422.

  1. On the containment problem for fat points ideals and Harbourne’s conjecture (with Yu Xie)

Proc. Amer. Math. Soc. 148 (2020), 2411-2419.

  1. Generalized minimum distance functions and algebraic invariants of Geramita ideals (with S. Cooper, A. Seceleanu, M. Vaz Pinto and R. Villarreal)

Advances in Applied Math. 112 (2020), 101940.

  1. On ideals generated by a-fold products of linear forms

J. Commutative Algebra 13 (2021), 549-570.

  1. Equivalent matrices up to permutations (with Jesus Vargas)

Unpublished; a version is available at arXiv: 1805.08343.

  1. Free arrangements with low exponents

Extended abstract published in Oberwolfach Reports 5 (2021) 59-61.

  1. A blowup algebra for hyperplane arrangements (with M. Garrousian and A. Simis)

Algebra & Number Theory 12 (2018), 1401-1429.

  1. Subspace arrangements as generalized star configurations

Mathematische Nachrichten 290 (2017), 3029-3037.

  1. Generalized star configurations and the Tutte polynomial (with B. Anzis and M. Garrousian)

J. Algebraic Combinatorics 42 (2017), 165-187.

  1. On the geometry of real or complex supersolvable line arrangements (with B. Anzis)

J. Combinatorial Theory, Series A 140 (2016), 76-96.

  1. On a conjecture of Vasconcelos via Sylvester forms (with R. Burity and A. Simis)

J. Symbolic Computation 77 (2016), 39-62.

  1. Projective duality of arrangements with quadratic logarithmic vector fields

Discrete Mathematics 339 (2016), 54-61.

  1. Star Configurations are Set-Theoretic Complete Intersection

Archiv der Mathematik 105 (2015), 343-349.

  1. Minimum distance of linear codes and the \alpha-invariant (with M. Garrousian)

Advances in Applied Math. 71 (2015), 190-207.

  1. Error-correction of linear codes via colon ideals (with B. Anzis)

J. Algebra (C.S.) 443 (2015), 479-493.

  1. The ubiquity of Sylvester forms in almost complete intersections (with A. Simis)

Collectanea Math. 66 (2015), 1-31.

  1. Finding inverse systems from coordinates

J. Algebra 400 (2014), 72-77.

  1. Modular decomposition of the Orlik-Terao algebra of a hyperplane arrangement (with G. Denham and M. Garrousian)
    Annals of Combinatorics 18 (2014), 289-312.
  2. Homology of homogeneous divisors (with A. Simis)
    Israel J. Math. 200 (2014), 449-487.
  3. A commutative algebraic approach to the fitting problem
    Proc. Amer. Math. Soc. 142 (2014), 659-666.
  4. A computational criterion for the supersolvability of line arrangements
    Ars Combinatoria  117 (2014), 217-223.
  5. From Splines Approximation to Roth's Equation and Schur Functors (with J. Minac)
    Manuscripta Math. 142(1) (2013), 101-126.
  6. On freeness of divisors on P^2
    Communications in Algebra 41(8) (2013), 2916-2932.
  7. Growth of the ideal generated by a quadratic multivariate function over GF(3) (with T. Hodges, J. Ding, V. Kruglov, D. Schmidt)
    J. Algebra Appl. 12 (2013), 1250219-1 to 23.
  8. Bounding invariants of fat points using a Coding Theory construction (with A. Van Tuyl)
    J. Pure Appl. Algebra 217(2013), 269-279.
  9. The minimum distance of sets of points and the minimum socle degree
    J. Pure Appl. Algebra 215(2011), 2645-2651.
  10. On the De Boer-Pellikaan method for computing minimum distance
    J. Symbolic Computation 45(2010), 965-974.
  11. Lower bounds on minimal distance of evaluation codes
    Appl. Algebra Eng. Commun. Comput. 20(5-6)(2009), 351-360.
  12. The Orlik-Terao algebra and 2-formality (with H. Schenck)
    Math. Res. Lett. 16(1)(2009), 171-182.
  13. Freeness of Conic-Line Arrangements in P^2 (with H. Schenck)
    Commentarii Mathematici Helvetici 84 (2009) 235-258.
  14. Mutant Grobner basis algorithm (with J. Ding, D. Cabarcas, D. Schmidt and J. Buchmann)
    Proceedings of the 1st international conference on Symbolic Computation and Cryptography, Beijing, LMIB, pp. 16-22 (2008).
  15. Topological criteria for k-formal arrangements
    Beitrage zur Algebra und Geometrie 48(1)(2007), 27-34.
  16. Smooth planar r-splines of degree 2r
    J. Approx. Theory 132(2005), 72-76.