Research
MathSciNet
Google Scholar
arXiv
ORCID
Web of Science
Grants and awards
Principal investigator of UFOCLAN: Universal quadratic forms and class numbers grant
- from the Czech Science Foundation GAČR, 2021–2025
- highly selective JUNIOR STAR project (success rate 9%, total budget 1 000 000 USD)
- postdocs: Giacomo Cherubini (01/2021–10/2022), Nicolas Daans (01–11/2023), Alessandro Fazzari (09–12/2021), Stevan Gajović (from 03/2023), Daniel Gil Muñoz (08/2021–06/2023), Siu Hang “Gordon” Man (from 07/2023), Mentzelos Melistas (from 01/2023), Eric Nathan Stucky (08/2021–08/2022), Błażej Żmija (10/2021–06/2023), a few more may be hired later
Principal investigator of Primus grant Universal quadratic forms: geometry and analysis
- from Charles University, 2020–2022
- postdocs: Giacomo Cherubini (09–12/2020), Siu Hang “Gordon” Man (09–12/2022), Tomáš Vávra (05–08/2020), Pavlo Yatsyna (01/2020–07/2022)
Principal investigator of Junior grant Quadratic forms and numeration systems over number fields
- from the Czech Science Foundation GAČR, 2017–2019
- postdocs: Tomáš Hejda, Tomáš Vávra (both 01/2017–12/2019), Ezra Waxman (08/2018–07/2019)
- outcomes of the grant were evaluated by the grant agency as excellent (top 20%)
Neuron Impuls award for the project Semifields in number theory and geometry for 2018–2019
Bolzano Award for 2018 for the work Universal quadratic forms and families of number fields
University Center of Excellence: junior team member, PI Jan Krajíček
Service (selected)
Chair of the Evaluation Panel P202 “Mathematics and Informatics” of Czech Science Foundation GACR (2023–2025; previously vice chair 2021–2023)
Member of the Committee of programs for the support of science at Charles University (evaluating internal grant proposals, from 2023)
Member of the Cooperatio advisory board for mathematics, Charles University (from 2022)
Member of the Academic Senate of the Faculty of Math. and Physics, Charles University (02/2020–01/2023)
Editorial board member of Commentationes Mathematicae Universitatis Carolinae
Editorial board member of Pokroky matematiky, fyziky a astronomie (Advances in mathematics, physics, and astronomy), Czech journal for popularization of math and physics
Articles
Most of my recent papers are on arXiv (although the published versions are typically slightly different). Please email me if you are interested in copies or preprints of my theses and other papers.
Six of my best papers are highlighted in bold.
37. (with M. Zindulka) Partitions into powers of an algebraic number, 8 pp., submitted
36. (with T. Kepka, M. Korbelář) Congruence-simple matrix semirings, 11 pp., submitted
35. (with E. Sgallová, M. Tinková) Arithmetic of cubic number fields: Jacobi-Perron, Pythagoras, and indecomposables, 40 pp. (+21 pp. of appendices), submitted
34. (with P. Yatsyna, B. Żmija) Real quadratic fields with a universal form of given rank have density zero, 18 pp., submitted
33. (with P. Miska) On continued fraction coefficients of square roots of primes, 13 pp., submitted
32. (with L. Šíma) On generators of commutative semifields, 12 pp., submitted
31. (with G. Cherubini, A. Fazzari, A. Granville, P. Yatsyna) Consecutive real quadratic fields with large class numbers, Int. Math. Res. Not. IMRN (to appear), 12 pp. journal, arxiv
30. Universal quadratic forms and indecomposables in number fields: A survey, Commun. Math. 31 (2023), Special issue: Euclidean lattices: theory and applications (to appear), 21 pp.
29. (with P. Yatsyna) On Kitaoka’s conjecture and lifting problem for universal quadratic forms, Bull. London Math. Soc. 55 (2023), 854–864. journal
28. Number fields without universal quadratic forms of small rank exist in most degrees, Math. Proc. Cambridge Philos. Soc. 174 (2023), 225–231. journal
27. (with M. Tinková) Universal quadratic forms, small norms and traces in families of number fields, Int. Math. Res. Not. IMRN (2023), 7541–7577. arxiv (not fully updated, use journal link)
26. (with T. Hejda) Ternary quadratic forms representing a given arithmetic progression, J. Number Theory 234 (2022), 140–152. journal
25. (with P. Yatsyna) Lifting problem for universal quadratic forms, Adv. Math. 377 (2021), 107497, 24 pp. journal
24. (with P. Yatsyna) Sums of squares in S-integers, New York J. Math. 26 (2020), 1145–1154. journal
23. (with T. Hejda) Additive structure of totally positive quadratic integers, Manuscripta Math. 163 (2020), 263–278. journal
22. (with J. Svoboda) Universal quadratic forms over multiquadratic fields, Ramanujan J. 48 (2019), 151–157. journal
21. (with T. Vávra) Periodic representations in algebraic bases, Monatsh. Math. 188 (2019), 109–119. journal
20. (with M. Korbelář) Idempotence of finitely generated commutative semifields, Forum Math. 30 (2018), 1461–1474. journal
19. (with A. Dahl) Distribution of class numbers in continued fraction families of real quadratic fields, Proc. Edinb. Math. Soc. 61 (2018), 1193–1212. journal
18. (with V. Blomer) On the rank of universal quadratic forms over real quadratic fields, Doc. Math. 23 (2018), 15–34. journal
17. (with P. Glivický) Fermat’s Last Theorem and Catalan Conjecture in weak exponential arithmetics, Math. Log. Quart. 63 (2017), 162–174. journal
16. Semifields and a theorem of Abhyankar, Comment. Math. Univ. Carolin. 58 (2017), 267–273. journal
15. Lattice-ordered abelian groups finitely generated as semirings, J. Commut. Algebra 9 (2017), 387–412. journal
14. Norms of indecomposable integers in real quadratic fields, J. Number Theory 166 (2016), 193–207. journal; additional info
13. Universal quadratic forms and elements of small norm in real quadratic fields, Bull. Aust. Math. Soc. 94 (2016), 7–14. journal
12. (with V. Blomer) Number fields without universal n-ary quadratic forms, Math. Proc. Cambridge Philos. Soc. 159 (2015), 239–252. journal
11. (with J. Berg, A. Castillo, R. Grizzard, R. Moy, C. Wang) Congruences for Ramanujan’s f and omega functions via generalized Borcherds products, Ramanujan J. 35 (2014), 327–338. journal
10. (with J. Ježek, T. Kepka) Finitely generated algebraic structures with various divisibility conditions, Forum Math. 24 (2012), 379–397
9. (with M. Korbelar) Congruence simple subsemirings of Q^+, Semigroup Forum 81 (2010), 286–296
8. (with A. Drapal, C. Hamalainen) Latin bitrades, dissections of equilateral triangles and abelian groups, J. Comb. Des. 18 (2010), 1–24
7. (with T. Kepka, P. Nemec) Norms on semirings I, Acta Univ. Carolin. Math. Phys. 51 (2010), 29–48
6. (with T. Kepka) Commutative parasemifields finitely generated as semirings, Acta Univ. Carolin. Math. Phys. 51 (2010), 49–56
5. (with T. Kepka, M. Korbelar) Notes on commutative parasemifields, Comment. Math. Univ. Carolin. 50 (2009), 521–533
4. (with A. D. Keedwell) Addendum to “The existence of Buchsteiner and conjugacy-closed quasigroups”, Europ. J. Combin. 30 (2009), 1386
3. (with T. Kepka, M. Korbelar, J. D. Phillips) Various subsemirings of the field Q of the rational numbers, Acta Univ. Carolin. Math. Phys. 50 (2009), 29–59
2. (with T. Kepka) A note on finitely generated ideal-simple commutative semirings, Comment. Math. Univ. Carolin. 49 (2008), 1–9
1. (with V. Flaska, A. Jancarik, T. Kepka) Trees in commutative nil-semigroups of index two, Acta Univ. Carolin Math. Phys. 48 (2007), 81–101
Presentations
Typically I give blackboard talks, so here are just a few of my beamer presentations.
Warning: The slides contain intentional simplification and (certainly some!) unintentional errors. Use with caution!
Universal quadratic forms over number fields — from International Conference on Class Groups of Number Fields and Related Topics 2021. video
Universal quadratic forms over number fields — a (semi)-popular talk from Number theory seminar, Prague, 2021. video
Lifting problem for universal quadratic forms — from XXXIst Journées Arithmétiques, 2019
Classifications of finitely generated semifields and lattice-ordered groups — from 56th SSAOS, 2018
Universal quadratic forms over number fields — from XXXth Journées Arithmétiques, 2017
Additively indecomposable integers in number fields — from ALaNT 4, 2016
Theses
Universal quadratic forms over number fields, 2020, habilitation thesis (don’t read – the survey paper gives a better overview of my recent research).
Density of Self-Dual Automorphic Representations of GL_n(A_Q), 2014, PhD thesis, Purdue University, advisor F. Shahidi
Algebraic Substructures in C^m, 2013, PhD thesis, Charles University, advisor T. Kepka
Simple semirings, 2009, Master’s thesis (Mgr.), advisor T. Kepka
Simple semirings, 2007, undergraduate thesis (Bc.), advisor T. Kepka
Prvociselne vzorce (Prime-generating functions), 2004, high school graduation thesis, supervisor R. Kucera
Popular
2018 Abel Prize awarded for Langlands program (in Czech), Pokroky matematiky, fyziky a astronomie, 63 (2018), 78–90
Dividing a treasure (in Czech), Rozhledy matematicko-fyzikální 92 (2017), 35–36