Jarmo Jääskeläinen

Ph.D., yliopistonlehtori / University Lecturer

Address

• Department of Economics and Management, Koetilantie 5, P.O. Box 28, 00014 University of Helsinki, Finland

Room

• 313 (Viikki Campus, Koetilantie 5)

Email

• jarmo.jaaskelainen@helsinki.fi

Other Sites

• Helsinki.fi, Research portal

Interests

• I am an expert on partial differential equations and the calculus of variations. I am interested in using the optimal control theory, dynamical optimisation methods and other mathematical tools in environmental and resource economics. I teach mathematics for economists.

Papers & Preprints

• 9. Restoring the Commons: Optimizing the Restoration of Natural Assets (with Pauli Lappi), Economic Theory (2025) to appear, postprint (pdf)
• 8. Homeomorphic Sobolev extensions of parametrizations of Jordan curves (with Ondrěj Bouchala, Pekka Koskela, Haiqing Xu and Xilin Zhou), Journal of Functional Analysis (2025) 288 (4), doi:10.1016/j.jfa.2024.110721, preprint in arXiv:2408.00506
• 7. Improved Hölder regularity for strongly elliptic PDEs (with Kari Astala, Albert Clop, Daniel Faraco and Aleksis Koski), Journal de Mathématiques Pures et Appliquées (2020) 140: 230–258, doi:10.1016/j.matpur.2020.06.005, preprint in arXiv:1906.10906
• 6. The Radó-Kneser-Choquet theorem for p-harmonic mappings between Riemannian surfaces (with Tomasz Adamowicz and Aleksis Koski), Revista Matemática Iberoamericana, (2020) 36 (6): 1779–1834, doi:10.4171/rmi/1183, postprint in JYX, preprint in arXiv:1806.03020
• 5. Nonlinear Beltrami operators, Schauder estimates and bounds for the Jacobian (with Kari Astala, Albert Clop, Daniel Faraco and Aleksis Koski), Annales de l'Institut Henri Poincaré (C) Analyse Non Linéaire (2017) 34 (6): 1543–1559, doi:10.1016/j.anihpc.2016.10.008, preprint in arXiv:1511.08370
• 4. Manifolds of quasiconformal mappings and the nonlinear Beltrami equation (with Kari Astala, Albert Clop and Daniel Faraco), Journal d'Analyse Mathematique (2019) 139 (1): 207–238, doi:10.1007/s11854-019-0059-x, postprint in JYX, preprint in arXiv:1412.4046
• 3. Uniqueness of Normalized Homeomorphic Solutions to Nonlinear Beltrami Equations (with Kari Astala, Albert Clop, Daniel Faraco and László Székelyhidi Jr.), International Mathematics Research Notices IMRN (2012) 2012 (18): 4101–4119, doi:10.1093/imrn/rnr178, preprint in arXiv:1012.2827
• 2. On reduced Beltrami equations and linear families of quasiregular mappings, Journal für die reine und angewandte Mathematik (Crelles Journal) (2013) 682: 49–64, doi:10.1515/crelle-2012-0041, preprint in arXiv:1009.2614
• 1. Homeomorphic solutions to reduced Beltrami equations (with Kari Astala), Annales Academiæ Scientiarum Fennicæ Mathematica (2009) 34: 607–613, preprint in arXiv:0812.2322

Dissertation

• On Linear and Nonlinear Beltrami Systems, Ph.D. dissertation, University of Helsinki, collecting papers 1.–3.    [handout slides of Lectio praecursoria]

Own Projects

• I have been funded by Academy of Finland (nowadays Research Council of Finland) projects no. 276233 and 318636: Nonlinear Elliptic Equations, Quasiharmonic Fields, and the Range of the Differential at the University of Helsinki 01.09.2014–31.08.2017 and at the University of Jyväskylä 01.09.2017–28.02.2018.

Prizes

• Vuoden opetusteko 2024

Teaching

• RATKOMO, University of Helsinki, 2022-2025
• Talousmatematiikka, University of Helsinki, Spring 2025
• Matematiikka 1, 2 ja 3, University of Helsinki, Autumn 2024

Talks & Presentations