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
- Kateřina Kalová (from 03/2026)
- Siu Hang “Gordon” Man (PI from 01/2025; postdoc 09/2022-12/2024)
- Pavlo Yatsyna (from 01/2024)
Postdocs
- Jérémy Dousselin (from 09/2025)
- Akash Singha Roy (from 12/2025)
- Subham Roy (from 08/2024)
- Stelios Sachpazis (from 09/2025)
- Robin Visser (from 10/2024)
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.
Conference
Quadratic Lattices in Prague, August 17–21, 2026
News
Vita became an editor of Communications in Mathematics (a diamond open-access journal). Please submit your good articles through the online system!
The Czech Academy of Sciences awarded Vita the degree DSc. (Doctor of Science or Research Professor), for his dissertation on Arithmetic of small elements in totally real fields.
Vita gave an online talk at the One World Numeration Seminar on Using geometric continued fractions for universal quadratic forms (video is available here). Also, at the Rényi Institute, he gave a Colloquium talk on Universal quadratic forms and Northcott property of infinite number fields, and a Number Theory Seminar talk on Consecutive real quadratic and cubic fields with large class number.
Two papers written by our students on universality of generalized quadratic forms were recently accepted by New York J. Math. and Ramanujan J.
Simona Fryšová won a GAUK student grant for her project on Universal and indecomposable lattices over number fields (2026-2028).
Martí Oller Riera won our recent job call and will join our team as a new postdoc from September 2026.
We’re organizing a conference on quadratic forms, lattices, and number fields in Prague on August 17-21, 2026. The registration is now open at the conference website.
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%
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: Kristýna Kramer, Giuliano Romeo, Akash Singha Roy, Stelios Sachpazis, Jongheun Yoon
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
Aperiodic sequences in number theory
Return Grant
PI Kateřina Kalová
from Charles University, 2026–2029
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
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 - Kristýna Kramer (06/2025–12/2025)
- 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 - Giuliano Romeo (07/2025–12/2025)
next job: postdoc at University of Trento - 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 - Jongheun Yoon (01/2025–12/2025)
next job: postdoc at Seoul National University - Błażej Żmija (10/2021–06/2023, and 07/2025–12/2025)
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
