Siegfried Carl
Professor of Mathematics
Professor of Mathematics

Postal Address Prof. Dr. Siegfried Carl Martin-Luther-Universität Halle-Wittenberg Institut für Mathematik 06099 Halle, Germany
Research Interests - Nonlinear Analysis - Nonsmooth Variational Problems
(Variational- and Hemivariational Inequalities) - Nonlinear Elliptic and Parabolic Differential Equations and Inclusions - Comparison Principles - Multiple Solutions in Nonlinear Elliptic Problems - Nonlinear Eigenvalue Problems
Siegfried Carl - Professor of Mathematics
Curriculum Vitae
Education
- 1975 Master in Mathematics (Diploma in Mathematics), University of Halle, Germany
- 1984 Ph.D. in Mathematics (Dr.rer.nat.), University of Halle, Germany
- 1990 postdoctoral qualification - Dr.rer.nat.habil. (Habilitation), Department of Mathematics and Computer Science, Institute of Technology (Technische Hochschule), Merseburg, Germany
- 1975-1981 Researcher, Academy of Science Institute of Solid State Physics and Electron Microscopy, Halle, Germany
- 1981-1984 Ph.D.-Research Fellow, Department of Mathematics, University of Halle, Germany
- 1984-1993 Assistant and Senior Assistant, Department of Mathematics and Computer Science, Institute of Technology, Merseburg, Germany
- 1993-1995 Privatdozent, Department of Mathematics and Computer Science, University of Halle, Germany
- since 1995 Professor of Mathematics, Institute of Mathematics, University of Halle, Germany
- 1990 (1 month) Department of Mathematics, University of Oulu, Finland
- 1994 (2 months) Department of Applied Mathematics, Florida Institute of Technology, Melbourne, FL, USA
- 1994, LEOPOLDINA-RESEARCH GRANT AWARD from GERMAN ACADEMY OF SCIENCES LEOPOLDINA (including a Leopoldina Scholarship for a 6-months research stay abroad)
- 1995 (6 months) Department of Mathematics, North Carolina State University, Raleigh, USA
- 1996 (1 month) Department of Mathematics, University of Oulu, Finland
- 1997 (1 month) Department of Mathematics, University of Oulu, Finland
- 1998 (5 weeks) Department of Mathematics, University of Oulu, Finland
- 2000 (1 month) Department of Mathematical Sciences, University of Delaware, USA and Department of Applied Mathematics, Florida Institute of Technology, Melbourne, FL, USA
- 2001-2002 (1 academic year) Visiting Professor at the Department of Applied Mathematics, Florida Institute of Technology, Melbourne, FL, USA
- 2005 (1 month) Visiting Professor at the Department of Mathematics, University of Perpignan, France
- 2008 (1 month) Visiting Professor at the Department of Mathematics, University of Perpignan, France
Siegfried Carl - Professor of Mathematics
Publications
Monographs
- Siegfried Carl and Vy Khoi Le, Multi-Valued Variational Inequalities and Inclusions, Springer Monographs in Mathematics, Springer, New York, 2021.
- Siegfried Carl and Seppo Heikkilä, Fixed Point Theory in Ordered Sets and Applications, Springer, New York, 2011.
- Siegfried Carl, Vy Khoi Le, and Dumitru Motreanu, Nonsmooth Variational Problems and Their Inequalities, Springer Monographs in Mathematics, Springer, New York, 2007.
- S. Carl and S. Heikkilä, Nonlinear Differential Equations In Ordered Spaces, Chapman & Hall/CRC, London, 2000.
- Carl, S., Extremal solutions of quasilinear elliptic variational inequalities in exterior domains, Pure Appl. Funct. Anal., to appear (in: Special Issue on Analysis and PDE in memory of Professor Louis Nirenberg).
- Carl, S., and Le, Vy K., On systems of parabolic variational inequalities with multivalued terms, Monatsh. Math. 194 (2021), no. 2, 227-260.
- Carl, S., N-Laplacian elliptic equations in exterior domains via Kelvin transform, Pure Appl. Funct. Anal. (in: Special Issue on Analysis and PDE dedicated to Professor H. Brezis on the occasion of his 75th birthday) 5 (2020), no. 4, 869-890.
- Carl, S., and Le, Vy K., Extremal solutions of multi-valued variational inequalities in plane exterior domains, J. Differential Equations (2019), https://doi.org/10.1016/j.jde.2019.05.020
- Carl, S., Costa, David G., Fotouhi, M., and Tehrani, H., Invariance of critical points under Kelvin transform and multiple solutions in exterior domains of R^2, Calc. Var. Partial Differential Equations 58 (2019), no. 2, Art. 65, 24 pp.
- Carl, S., Costa, David G., and Tehrani, H., Extremal solutions of logistic-type equations in exterior domain in R^2, Nonlinear Anal. 176 (2018), 272-287.
- Carl, S., Tietz, Ch., Quasilinear elliptic equations with measures and multi-valued lower order terms, Discrete Contin. Dyn. Syst. Ser. S 11 (2018), no. 2, 193-212.
- Carl, S., Decay estimates for Wolff potentials in R^N and gradient-dependent quasilinear elliptic equations, J. Differential Equations 265 (2018), no. 8, 3685-3708.
- Carl, S., and Motreanu, D., Extremal solutions for quasilinear parabolic systems in trapping regions, Pure and Applied Functional Analysis 3 (2018), no. 1, 57-74.
- Carl, S., Costa, David G., and Tehrani, H., D^{1,2}(R^N) versus C(R^N) local minimizer on manifolds and multiple solutions for zero-mass equations in R^N, Advances in Calculus of Variations 11 (2018), no. 3, 257-272.
- Carl, S., Extremal solutions of p-Laplacian problems in D^{1,p}(R^N) via Wolff potential estimates, J. Differential Equations 263 (2017), 3370-3395.
- Carl, S., and Motreanu, D., Extremal solutions for nonvariational quasilinear elliptic systems via expanding trapping regions, Monatsh Math 182 (2017), no. 4, 801-821.
- Carl, S., Costa, David G., and Tehrani, H., D^{1,2}(R^N) versus C(R^N) local minimizer and a Hopf-type maximum principle, J. Differential Equations 261 (2016), 2006-2025.
- Carl, S., Costa, David G., and Tehrani, H., Extremal and sign-changing solutions of supercritical logistic-type equations in R^N, Calc. Var. Partial Differential Equations 54 (2015), no. 4, 4143-4164.
- Carl, S., Barrier solutions of elliptic variational inequalities, Nonlinear Anal. Real World Appl. 26 (2015), 75-92.
- Carl, S., and Motreanu, D., Multiple solutions for elliptic systems via trapping regions and related nonsmooth potentials, Appl. Anal. 94 (2015), no. 8, 1594-1613.
- Carl, S., and D'Ambrosio, L., Foreword [Nonlinear partial differential equations, in honor of Enzo Mitidieri on his 60th birthday], Nonlinear Anal. 121 (2015), 1-2.
- Carl, S., and Vy K. Le, Elliptic inequalities with multi-valued operators: existence, comparison and related variational-hemivariational type inequalities, Nonlinear Anal. 121 (2015), 130-152.
- Carl, S., and Le, V. K., Multi-Valued Parabolic Variational Inequalities and Related Variational-Hemivariational Inequalities, Advanced Nonlinear Studies 14 (2014), 603-631.
- Carl, S., and Le, V. K., Quasilinear Parabolic Variational Inequalities with Multi-Valued Lower Order Terms, Z. Angew. Math. Phys. 65 (2014), 845-864
- Carl, S., Existence and Extremal Solutions of Parabolic Variational-Hemivariational Inequalities, Monatsh. Math. 172 (2013), 29-54.
- Candito, P., Carl, S., and Livrea, R., Variational versus pseudomonotone operator approach in parameter-dependent nonlinear elliptic problems, Dynam. Systems Appl. 22 (2013), 397-410.
- Carl, S., Signorini type variational inequality with state-dependent discontinuous multivalued boundary operators, Nonlinear Anal. 92 (2013), 138-152.
- Carl, S., Elliptic variational inequalities with discontinuous multi-valued lower order terms, Adv. Nonlinear Stud. 13 (2013), 55-78.
Siegfried Carl - Professor of Mathematics
Editorial Work
Editorial Board Member of the following international mathematical journals:
- Associate Editor: Journal of Inequalities and Applications (January 2003 - December 2011)
- Associate Editor: Nonlinear Analysis (2004 - 2009)
- Associate Editor: Nonlinear Analysis: Real World Applications (January 2009 - March 2012)
- Associate Editor: Applicable Analysis (since 2001)
- Editor-in-Chief: Nonlinear Analysis (2009 - 2019)
- Honorary Editor: Nonlinear Analysis (since 2019)
Siegfried Carl - Professor of Mathematics
Teaching
The following list provides a selection of courses taught in recent years:
- Basic courses in Analysis:
- Real Analysis in one and higher dimensions
- Ordinary Differential Equations
- Function Theory of One Complex Variable
- Measure Theory
- Introduction to Linear Functional Analysis
- Nonlinear Analysis:
- Monotone and Pseudomonotone Operators
- Variational Inequalities
- Variational Methods
- Partial Differential Equations
- Functional Analysis and its Applications to Partial Differential Equations
- Differential Inequalities: Maximum and Comparison Principles
Siegfried Carl - Professor of Mathematics
Projects
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