Stockholm university
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Sofia Tirabassi

About me

Starting January 2nd 2019 I am an associate professor at the Department of Mathematics  of Stockholm University. I earned my docentship in May 2021. Since July 1st 2021, I have been also be the pricipal Investigator of the project "Derived Categories in Positive Characteristic" funded by the KAW fundation under the scheme "International Postdoctoral Scholarship". I was the manager of the project "The Arithmetic of Derived Categories" funded by the Research Council of Norway under the scheme "Young Research Talents" for the years 2017-2021.
 
From August 2015 till December 2020, I was an associate professor at the University of Bergen. Before that, from January 1st 2013 to July 31st 2015, I was a Postdoctoral Research Assistant Professor at the Mathematics Department of University of Utah (Salt Lake City (UT), USA). In 2012, I was a Marie Curie Fellow at the Faculty of Mathematics, Informatics and Mechanics, University of Warsaw. This fellowship was awarded by "The ERCIM Alain Bensoussan Fellowship Programme" and was supported by the Marie Curie Co-funding of Regional, National and International Programmes (COFUND) of the European Commission.

In February 2012, I completed my Ph.D. in Mathematics at the Università degli studi Roma TRE with a thesis entitled Syzygies, Pluricanonical Maps and the Birational Geometry of Irregular Varieties, written under the supervision of Prof. G. Pareschi (Università degli studi di Roma "Tor Vergata").

Before entering in the Ph.D. program of the Università degli Studi Roma TRE, I was a student at the University of Bologna where I completed both my B.Sc. in Mathematics (2006) and M.Sc. in Mathematics (2008).
 

 

Research interests: 

My primary field of interest is the study of Algebraic Geometry with cohomological methods. 

I have currently two ongoing projects. On one side, I  study derived categories and derived invariants of algebraic varieties defined over fields of positive characteristic. On the other side,  I am  working on finding an effective birational characterization of semiabelian varieties.

 

Publications and Preprints:

Preprints:
  1. A footnote to a theorem of Kawamata (With M. Mendes Lopers and R. Pardini). To appear on Math. Nach.
  2. Effective characterization of quasi-abelian surfaces (With M. Mendes Lopes and R. Pardini). To appear on Forum Math. Sigma
  3. Counting Twisted Tame Fourier-Mukai Partners of an Ordinary K3 Surface (With T. Srivastava). To appear on MRL.

Published research papers:

  1.  On the Brauer Group of Bielliptic Surfaces (With E. Ferrari, M. Vodrup, and an Appendix with J. Bergström).  Documenta Matematica 2022.
  2. On Ordinary Enriques Surfaces in Positive Characteristic (with R. Laface). Nagoya math Journal 2020.
  3. Theta-regularity and log-canonical threshold (With M. Ø ygarden). Mathematica Scandinavica 2021.
  4. Fourier-Mukai partners of Enriques and bielliptic surfaces in positive characteristic. Mathematical Research Letter 2021.
  5. Derived equivalences of canonical covers of hyperelliptic and Enriques surfaces in positive characteristic (With K. Honigs and L. Lombardi). Math Z 2019
  6. A note on the derived category of Enriques surfaces in characteristic 2. Bollettino dell'Unione Matematica Italiana (2016). DOI:10.1007/s40574-016-0100-2
  7. Deformations of minimal cohomology classes on abelian varieties. (With L. Lombardi). Communications in Contemporary Mathematics DOI:10.1142/S0219199715500662
  8. GV-Schemes and their embeddings in principally polarized abelian varieteis. (With L. Lombardi). Mathematische Nachrichten, DOI: 10.1002/mana.201400238
  9. Characterization of products of theta divisors. (With Z. Jiang and M. Lahoz). Compositio Mathematica150 (2014): 1384-1412. 
  10. Syzygies and Equations of Kummer Varieties. Bulletin of London Mathematical Society (2013) 45 (3):651-665. 
  11. On the Iitaka Fibration of Varieties of Maximal Albanese Dimension. (With Z. Jiang and M. Lahoz) International Mathematics Research Notices, (2012). 
  12. On the Tetracanonical Map of Varieties of General Type and Maximal Albanese Fimension. Collectanea Mathematica, (2011).
  13. Derived Categories of Fano Toric 3-folds via Frobenius Morphism. (With A. Bernardi) Le Matematiche, Volume: LXIV, Issue: II (2010). 

 

 


 

Research projects

Unknown properties of abstract geometric objects

This is a project in algebraic geometry, the branch of mathematics which is concerned with the study of geometric objects that can be described through polynomial equations. These are called (algebraic) varieties.

Research

Publications

A selection from Stockholm University publication database

  • Theta-regularity and log-canonical threshold

    2020. Morten Øygarden, Sofia Tirabassi. Mathematica Scandinavica 126 (1), 73-81

    Article

    We show that an inequality, proven by Küronya-Pintye, which governs the behavior of the log-canonical threshold of an ideal over Pn and that of its Castelnuovo-Mumford regularity, can be applied to the setting of principally polarized abelian varieties by substituting the Castelnuovo-Mumford regularity with Θ-regularity of Pareschi-Popa.

    Read more about Theta-regularity and log-canonical threshold

  • Derived equivalences of canonical covers of hyperelliptic and Enriques surfaces in positive characteristic

    2020. Katrina Honigs, Luigi Lombardi, Sofia Tirabassi. Mathematische Zeitschrift 295, 727-749

    Article

    We prove that any Fourier–Mukai partner of an abelian surface over an algebraically closed field of positive characteristic is isomorphic to a moduli space of Gieseker-stable sheaves. We apply this fact to show that the set of Fourier–Mukai partners of a canonical cover of a hyperelliptic or Enriques surface over an algebraically closed field of characteristic greater than three is trivial. These results extend earlier results of Bridgeland–Maciocia and Sosna to positive characteristic.

    Read more about Derived equivalences of canonical covers of hyperelliptic and Enriques surfaces in positive characteristic

  • ON ORDINARY ENRIQUES SURFACES IN POSITIVE CHARACTERISTIC

    2020. Roberto Laface, Sofia Tirabassi. Nagoya mathematical journal

    Article

    We give a notion of ordinary Enriques surfaces and their canonical lifts in any positive characteristic, and we prove Torelli-type results for this class of Enriques surfaces.

    Read more about ON ORDINARY ENRIQUES SURFACES IN POSITIVE CHARACTERISTIC

  • Fourier-Mukai partners of Enriques and bielliptic surfaces in positive characteristic

    2021. Katrina Honigs, Max Lieblich, Sofia Tirabassi. Mathematical Research Letters 28 (1), 65-91

    Article

    We prove that a twisted Enriques (respectively, untwisted bielliptic) surface over an algebraically closed field of positive characteristic at least 3 (respectively, at least 5) has no non-trivial Fourier-Mukai partners.

    Read more about Fourier-Mukai partners of Enriques and bielliptic surfaces in positive characteristic

  • GV-subschemes and their embeddings in principally polarizedabelian varieties

    2015. Luigi Lombardi, Sofia Tirabassi. Mathematische Nachrichten 288 (11-12), 1405-1412

    Article

    We prove that any embedding of a GV -subscheme in a principally polarized abelian variety does not factorthrough any nontrivial isogeny. As an application, we present a new proof of a theorem of Clemens–Griffithsidentifying the intermediate Jacobian of a smooth cubic threefold to the Albanese variety of its Fano surface oflines.

    Read more about GV-subschemes and their embeddings in principally polarizedabelian varieties

  • On the Brauer group of bielliptic surfaces (with an appendix by Jonas Bergström and Sofia Tirabassi)

    2022. Eugenia Ferrari (et al.). Documenta Mathematica 27, 383-425

    Article

    We provide explicit generators of the torsion of the second cohomology of bielliptic surfaces, and we use this to study the pullback map between the Brauer group of a bielliptic surface and that of its canonical cover.

    Read more about On the Brauer group of bielliptic surfaces (with an appendix by Jonas Bergström and Sofia Tirabassi)

Show all publications by Sofia Tirabassi at Stockholm University

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