UFOCLAN
UFOCLAN (Universal quadratic forms and class numbers) is our number theory research group at Charles University, Faculty of Mathematics and Physics, Department of Algebra.
Team members
Faculty
- Vita Kala (associate professor from 2022)
- Martin Čech (assistant professor from 2025; postdoc 09–12/2024)
PIs
- Siu Hang “Gordon” Man (PI from 01/2025; postdoc 09/2022-12/2024)
- Pavlo Yatsyna (from 01/2024)
Postdocs
- Jérémy Dousselin (from 09/2025)
- Kristýna Kramer (06/2025–12/2025)
- Giuliano Romeo (07/2025–12/2025)
- Akash Singha Roy (from 12/2025)
- Subham Roy (from 08/2024)
- Stelios Sachpazis (from 09/2025)
- Robin Visser (from 10/2024)
- Jongheun Yoon (01/2025–12/2025)
- Błażej Żmija (07/2025–12/2025)
Ph.D. students
- Simona Fryšová (from 2025, advisor P. Yatsyna)
- Om Prakash (from 2023, advisor V. Kala)
- Ritoprovo Roy (from 2025, advisor V. Kala)
We regularly have funding for hiring new postdocs and Ph.D. students. Interested very strong candidates are welcome to email Vita with informal inquiries. In particular, we will have a 2-year postdoc opening for 2026–2028 that will be advertised in December 2025 (on mathjobs and here). We also encourage very strong candidates to apply for this faculty position. We may hire a few very strong Ph.D. students to start in October 2026, see here.
News
Vita won a highly selective Standard grant Sailing to criterion sets for quadratic forms from the Czech Science Foundation that will fund our research for the next three years (the success rate was only 14%).
Vita joined the editorial board of International Journal of Number Theory. Feel free to submit your good papers through the online system!
Vita will give an invited talk at Weihnachtsworkshop on Geometry and Number Theory 2025 in Karlsruhe.
In our latest preprint, Dayoon, Jongheun, Pavlo, and Robin studied n-universal quadratic lattices over number fields, i.e., lattices that represent all integral lattices of rank n. We established strikingly precise results on the asymptotic growth of their ranks, as well as impressive results on the growth of the corresponding criterion sets.
Mikuláš Zindulka defended his Ph.D. thesis Arithmetics of number fields: partitions, norms, and quadratic forms advised by Vita. Now he’s moving to University of Hong Kong for a postdoc.
Funding
Sailing to criterion sets for quadratic forms
GAČR Standard project
PI Vita Kala
from the Czech Science Foundation GAČR, 2026–2028
success rate 14%
Universal quadratic forms and class numbers
GAČR Junior Star project
PI Vita Kala
from the Czech Science Foundation GAČR, 2021–2025
success rate 9%, total budget 1 000 000 USD
Multiple Dirichlet series and analytic number theory
Primus grant
PI Martin Čech
postdocs (partly) supported: Jérémy Dousselin, Stelios Sachpazis, Błażej Żmija
from Charles University, 2025–2028
Automorphic forms for symplectic groups via trace formula
Primus grant
PI Siu Hang “Gordon” Man
postdocs (partly) supported: Giuliano Romeo, Akash Singha Roy, Stelios Sachpazis, Jongheun Yoon, Kristýna Kramer
from Charles University, 2025–2028
Statistical properties of totally real number fields
Primus grant
PI Pavlo Yatsyna
postdocs (partly) supported: Martin Čech, Nicolas Daans, Siu Hang “Gordon” Man, Subham Roy, Robin Visser
from Charles University, 2024–2027
Universal quadratic forms: geometry and analysis
Primus grant
PI Vita Kala
from Charles University, 2020–2022
Quadratic forms and numeration systems over number fields
GAČR Junior grant
PI Vita Kala
from the Czech Science Foundation GAČR, 2017–2019
outcomes of the grant were evaluated by the grant agency as excellent (top 20%)
University research center UNCE
- PI Libor Barto, 2024–2029
Intersections of algebra, geometry, and informatics - PI Jan Krajíček, 2018–2023
Methods of algebra and logic
Our seminars
Number Theory Seminar
Algebra Colloquium
If you want to give a talk in either of these seminars, please let one of the organizers (eg Vita) know!
We have mailing lists for both seminars with weekly talk announcements – if you want to join them, please also let Vita know.
Team publications
See here.
Past team members
Postdocs
- Matteo Bordignon (01/2022–01/2023)
next job: postdoc at KTH Stockholm - Giacomo Cherubini (09/2020–10/2022)
next job: permanent position at Sapienza University of Rome - Nicolas Daans (01/2023–09/2024)
next job: postdocs at KU Leuven and University of Mons - Alessandro Fazzari (09–12/2021)
next job: postdoc at American Institute of Mathematics - Stevan Gajović (03/2023–12/2024)
next job: postdoc at MPIM Bonn - Daniel Gil Muñoz (08/2021–06/2023)
next job: postdoc at University of Barcelona - Tomáš Hejda (01/2017–12/2019)
next job: work for Overleaf - Mentzelos Melistas (01/2023–08/2023)
next job: tenure track lecturer at University of Twente - Dayoon Park (03/2024–09/2025)
next job: postdoc at UNIST, Korea - Eric Nathan Stucky (08/2021–08/2022)
next job: adjunct faculty member at Champlain College - Tomáš Vávra (01/2017–08/2020)
next job: postdoc at University of Waterloo - Ezra Waxman (08/2018–07/2019)
next job: postdoc at Dresden University with Minerva Fellowship - Pavlo Yatsyna (01/2020–07/2022)
next job: postdoc at Aalto University - Błażej Żmija (10/2021–06/2023)
next job: postdoc at Polish Academy of Sciences
Ph.D. students
- Jakub Krásenský (2018–2023)
next job: assistant professor (tenure track) at Czech Technical University in Prague, Faculty of Information Technology, Department of Applied Mathematics - Magdaléna Tinková (2017–2021)
next jobs: assistant professor (tenure track) at Czech Technical University in Prague, Faculty of Information Technology, Department of Applied Mathematics; and postdoc at TU Graz funded by Postdoc grant from Czech Science Foundation Mikuláš Zindulka (2021–2025)
next job: postdoc at University of Hong Kong
