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All Outputs (6)

On liftings of modular forms and Weil representations (2023)
Journal Article
STROMBERG, F. (2024). On liftings of modular forms and Weil representations. Forum Mathematicum, 36(1), 33-52. https://doi.org/10.1515/forum-2022-0353

We give an explicit construction of lifting maps from integral and half-integral modular forms to vector-valued modular forms for Weil representations associated with arbitrary isotropic subgroups and finite quadratic modules of even and odd signatur... Read More about On liftings of modular forms and Weil representations.

Derivatives of L-series of weakly holomorphic cusp forms (2022)
Journal Article
Diamantis, N., & Stromberg, F. (2022). Derivatives of L-series of weakly holomorphic cusp forms. Research in the Mathematical Sciences, 9(4), Article 64. https://doi.org/10.1007/s40687-022-00363-x

Based on the theory of L-series associated with weakly holomorphic modular forms in Diamantis et al. (L-series of harmonic Maass forms and a summation formula for harmonic lifts. arXiv:2107.12366), we derive explicit formulas for central values of de... Read More about Derivatives of L-series of weakly holomorphic cusp forms.

hilbertmodgroup: Reduction algorithms and framework forHilbert Modular Groups (2022)
Journal Article
Strömberg, F. (2022). hilbertmodgroup: Reduction algorithms and framework forHilbert Modular Groups. Journal of Open Source Software, 7(72), Article 3996. https://doi.org/10.21105/joss.03996

This package implements basic classes and a new reduction algorithm for Hilbert modular groups. The main improvement over previous algorithms is that this implementation works in theory for all Hilbert modular groups and in practice for a much wider... Read More about hilbertmodgroup: Reduction algorithms and framework forHilbert Modular Groups.

A reduction algorithm for Hilbert modular groups (2022)
Journal Article
Strömberg, F. (2022). A reduction algorithm for Hilbert modular groups. Journal of Number Theory, 241, 581-602. https://doi.org/10.1016/j.jnt.2022.02.011

The aim of this paper is to present an explicit reduction algorithm for Hilbert modular groups over arbitrary totally real number fields. An implementation of the algorithm is available to download from [20]. The exposition is self-contained and suff... Read More about A reduction algorithm for Hilbert modular groups.

Noncongruence subgroups and Maass waveforms (2018)
Journal Article
Strömberg, F. (2019). Noncongruence subgroups and Maass waveforms. Journal of Number Theory, 199, 436-493. https://doi.org/10.1016/j.jnt.2018.11.020

The main topic of the paper is spectral theory for noncongruence subgroups of the modular group. We have studied a selection of the main conjectures in the area: the Roelcke–Selberg and Phillips–Sarnak conjectures and Selberg's conjecture on exceptio... Read More about Noncongruence subgroups and Maass waveforms.

A correspondence of modular forms and applications to values of L-series (2015)
Journal Article
Diamantis, N., Neururer, M., & Strömberg, F. (in press). A correspondence of modular forms and applications to values of L-series. Research in Number Theory, 1(27), https://doi.org/10.1007/s40993-015-0029-z

An interpretation of the Rogers–Zudilin approach to the Boyd conjectures is established. This is based on a correspondence of modular forms which is of independent interest. We use the reinterpretation for two applications to values of L-series and v... Read More about A correspondence of modular forms and applications to values of L-series.