Dr. Dumitru I. Stamate

Contact information:
University of Bucharest
Faculty of Mathematics and Computer Science
Str. Academiei Nr. 14,
Sector 1, Bucharest 010014, Romania
phone : + 40-21-3143508
fax: + 40-21-3156990
e-mail: dumitru.stamate @ fmi.unibuc.ro
homepage: gta.math.unibuc.ro/~dumi


I am conferentiar universitar (associate professor) in the Department of Mathematics at the Faculty of Mathematics and Computer Science of the University of Bucharest. Since 2021 I am habilitated to advise Ph.D. students and I am a member of the Doctoral School in Mathematics at the University of Bucharest.

I did my undergraduate studies (B.Sc. 2002) in Maths at the University of Iasi, Romania. Later on I got a Masters degree from Iasi, and another one from SNSB-Bucharest (2004). I got my Ph.D. in Maths in 2009 from the University of Bucharest, under the supervision of Prof. Dorin Popescu. During the preparation of the thesis, in 2006-2008, I benefitted from a Fulbright Fellowship at the University of Minnesota, Minneapolis, where I worked with Prof. Vic Reiner. Before joining the University of Bucharest in Oct 2009, I worked as an assistant researcher at IMAR, the "Simion Stoilow" Institute of Mathematics of the Romanian Academy.
Here's a more detailed CV [pdf].

Editorial
I am in the editorial board of Analele stiintifice ale Universitatii "Al. I. Cuza" din Iasi. Matematica (Serie noua)/Annals of the "Alexandru Ioan Cuza" University of Iasi (New Series). Mathematics.


Teaching
My teaching schedule is available online.
If you would like to set up an appointment with me, the best way is to write me an email at dumitru.stamate W@W fmi.unibuc.ro. (after you remove the W's)
MSc and BSc theses coordinated: here.


Publications and research
My research is in commutative algebra, with an interest in problems related to free resolutions, computational algebra and combinatorics.

    Preprints:
  1. The toric ring of one dimensional simplicial complexes (with Antonino Ficarra and Juergen Herzog), preprint 2023, 16 pages, arXiv:2306.05020 [math.AC].
  2. The canonical trace of determinantal rings (with Antonino Ficarra, Juergen Herzog and Vijaylaxmi Trivedi), preprint 2022, 10 pages, arXiv:2212.00393 [math.AC].

    3. Peer-reviewed papers:
  3. The tiny trace ideals of the canonical modules in Cohen-Macaulay rings of dimension one (with Juergen Herzog and Shinya Kumashiro), Journal of Algebra 619 (2023), 626-642. DOI 10.1016/j.jalgebra.2022.12.026. Preprint arXiv:2106.09404 [math.AC].
  4. Stable set rings which are Gorenstein on the punctured spectrum (with Takayuki Hibi), Collectanea Mathematica 74 (2023), 219-224. DOI 10.1007/s13348-021-00343-4. Preprint arXiv:2108.09912 [math.AC].
  5. On the occurrence of complete intersections in shifted families of numerical semigroups, Research in the Mathematical Sciences 9 (2022), Article number: 32 (5 pp). DOI 10.1007/s40687-022-00328-0.
  6. Graded Bourbaki ideals of graded modules (with Juergen Herzog and Shinya Kumashiro), Mathematische Zeitschrift 299 (2021), 1303-1330. DOI 10.1007/s00209-021-02724-8. Preprint arXiv:2002.09596 [math.AC].
  7. Canonical trace ideal and residue for numerical semigroup rings (with Juergen Herzog and Takayuki Hibi), Semigroup Forum 103 (2021), 550-566. DOI 10.1007/s00233-021-10205-x. Preprint arXiv:2008.01428 [math.AC].
  8. Nearly Gorenstein rings arising from finite graphs (with Takayuki Hibi), Electronic Journal of Combinatorics 28 (3) (2021), #P3.28. 11 pages. DOI 10.37236/10356. Preprint arXiv:2103.17042 [math.AC].
  9. Ulrich elements in normal simplicial affine semigroups (with Juergen Herzog and Raheleh Jafari), Pacific Journal of Mathematics, Vol. 309 (2020), No. 2, 353-380. DOI 10.2140/pjm.2020.309.353. Preprint arXiv:1909.06846 [math.AC].
  10. Groebner-nice pairs of ideals (with Mircea Cimpoeas), In: Combinatorial Structures in Algebra and Geometry (D.I. Stamate, T. Szemberg Eds.), Springer Proceedings in Mathematics & Statistics, vol. 331 (2020), 15-29, Springer, Cham. DOI 10.1007/978-3-030-52111-0_2. Preprint arXiv:2101.08710 [math.AC].
  11. The trace of the canonical module (with Juergen Herzog and Takayuki Hibi), Israel Journal of Mathematics, Volume 233, Issue 1 (2019), 133-165. DOI 110.1007/s11856-019-1898-y. Preprint arXiv:1612.02723 [math.AC].
  12. Cohen-Macaulay criteria for projective monomial curves via Groebner bases (with Juergen Herzog), Acta Mathematica Vietnamica, Volume 44, Issue 1 (2019), 51-64. DOI 10.1007/s40306-018-00302-5. Preprint arXiv:1803.08961 [math.AC].
  13. Betti numbers for numerical semigroup rings, In: Multigraded Algebra and Applications (V. Ene, E. Miller, Eds.), Springer Proceedings in Mathematics & Statistics, vol 238 (2018), 133-157, Springer, Cham. DOI 10.1007/978-3-319-90493-1_8. Preprint arXiv:1801.00153 [math.AC].
  14. Anticanonical modules for Segre products (with Viviana Ene and Juergen Herzog), Bull. Math. Soc. Sci. Math. Roumanie, special issue honoring Prof. Dorin Popescu, Tome 60 (108) No. 4, 2017, 373-386. Preprint arXiv:1707.00305 [math.AC].
  15. Quadratic numerical semigroups and the Koszul property (with Juergen Herzog), Kyoto Journal of Mathematics, Volume 57, Number 3 (2017), 585-612. DOI 10.1215/21562261-2017-0007. Preprint arXiv:1510.00935 [math.AC].
  16. On intersections of complete intersection ideals (with Mircea Cimpoeas), Journal of Pure and Applied Algebra vol 220, no. 11 (2016), 3702-3712. DOI 10.1016/j.jpaa.2016.05.008. Preprint.
  17. Asymptotic properties in the shifted family of a numerical semigroup with few generators, Semigroup Forum, Volume 93, Issue 2 (2016) pp 225-246. DOI 10.1007/s00233-015-9724-2. Preprint.
  18. On the Cohen-Macaulay property for quadratic tangent cones, Electronic Journal of Combinatorics, Volume 23, Issue 3 (2016), Paper #P3.20. 22 pages. DOI 10.37236/5793. Preprint arXiv:1512.04893 [math.AC].
  19. On the defining equations of the tangent cone of a numerical semigroup ring (with Juergen Herzog), Journal of Algebra vol 418 (2014), 8-28. DOI 10.1016/j.jalgebra.2014.07.008. Preprint arXiv:1308.4644 [math.AC].
  20. Koszul incidence algebras, affine semigroups, and Stanley-Reisner ideals (with Victor Reiner), Advances in Mathematics 224 (2010), 2312-2345. DOI:10.1016/j.aim.2010.02.005. Preprint arXiv:0904.1683 [math.AC].

    21. Edited volume:
  21. Combinatorial Structures in Algebra and Geometry, NSA 26, Constanta, Romania, August 26-September 1, 2018, edited with Tomasz Szemberg, Springer Proceedings in Mathematics & Statistics, Vol. 331, 2020, Springer, Cham. viii+182 pp. ISBN 978-3-030-52110-3 (hardcover), 978-3-030-52111-0 (e-book). DOI 10.1007/978-3-030-52111-0.

    22. Theses:
  22. Computational algebra and combinatorics in commutative algebra, Ph.D. thesis, 2009, University of Bucharest, Romania.
    23. (Available upon request)
  23. Chordal graphs, Alexander duality and Cohen-Macaulayness, M.Sc. dissertation, Scoala Normala Superioara Bucuresti, Romania.
  24. Cohen-Macaulay rings and modules (in Romanian), M.Sc. dissertation, University "Al. I. Cuza" of Iasi, Romania.

    25. Software:
  25. (with David Eisenbud, Daniel Erman, Gregory G. Smith) TensorComplexes, a Macaulay2 package for constructing free complexes via multilinear algebra.

    26. Reports:
  26. (with Djordje Baralic, Marianne Merz, Paolo Sentinelli), A Gamma-equivariant setting for matroids, report at Discrete Morse Theory and Commutative Algebra, Institut Mittag Leffler, Sweden, July 2012, 5pp.
  27. (with Brett Barwick, Jennifer Biermann, David Cook II, W. Frank Moore, Claudiu Raicu) Boij-Soderberg Theory in the nonstandard graded case, report at MRC Snowbird, June 2010, 5 pp.

Some notes

Commutative Algebra Seminar
I attend the weekly Commutative Algebra Seminar which is run jointly by IMAR and FMI. It meets usually during the academic year on Tuesdays, 12-14, room 120, at the University building. Feel free to stop by!
The archive of the talks is found here.

Summer Schools
There was a Special Session: Homological Methods in Commutative Algebra on 4 July 2023, co-organized with Dorin Popescu, on the occasion of the 10th Congress of Romanian Mathematicians at the University of Pitesti.
There was a One Day Workshop on Commutative Algebra and Related Fields on 1 September 2020, hosted online on Webex by Ovidius University of Constanta. Co-organized by Viviana Ene and myself.

An important event that our group organizes yearly is the National School on Algebra.
The 28th edition took place 24-28 June 2023 at the University of Bucharest, with the topic Interactions between Algebra and Geometry in Bucharest, co-organized with Viviana Ene, Cristodor Ionescu and Marius Vladoiu.
In 2020 it was supposed to take place 8-12 June 2020, in Bucharest, with the topic Homological trends in Commutative Algebra and Algebraic Geometry. It will be rescheduled when life gets back to normal.
The 27th edition took place 20-24 May 2019, in Bucharest, with the topic Graded modules over polynomial rings with applications to free divisors.
The 26th edition took place 27-31 August 2018, in Constanta, with the title Combinatorial structures in algebra and geometry.
The 25th edition took place 4-8 September 2017, in Bucharest, with the title The regularity of the invariant National School on Algebra, a generic edition.

The 2016 meeting was organized under the patronship of the European Mathematical Society and with support from the Foundation Compositio Mathematica : EMS Summer School on Multigraded Algebra and Applications in Moieciu de Sus, Romania, 17-24 August 2016. Here are the slides for some of the talks in Moieciu.

Links