Ulrich Kohlenbach's homepage

Ulrich Kohlenbach

Professor of Mathematics
Research Group Logic

Department of Mathematics
Technische Universität Darmstadt
Schlossgartenstrasse 7
D-64289 Darmstadt, Germany
kohlenbach [at] mathematik [dot] tu-darmstadt [dot] de
Tel.: (+49) 06151-16-22862 (Office)
Tel.: (+49) 06151-16-22863 (Secretary)
Fax: (+49) 06151-16-22840

I obtained my PhD (Dr.phil.nat.) in 1990 from the Department of Mathematics of the J.W.Goethe-Universitaet Frankfurt (Germany).
In 1995 I got my Habilitation (`venia legendi') from the Department of Mathematics of the University of Frankfurt.
During the academic year 1996-97 I was a visiting assistant professor in the Department of Mathematics of the University of Michigan, Ann Arbor. In July 1997, I joined BRICS and the Department of Computer Science of Aarhus University (Aarhus, Denmark) where I became tenured associate professor in 2000. Since April 2004 I am full professor of mathematics at Technische Universität Darmstadt.

Research Interests: Logic (in particular proof theory, computability theory and constructive reasoning) with applications to mathematics and computer science, computational content of proofs, proof interpretations and their use in mathematics, functionals of higher type, approximation theory, nonlinear analysis, fixed point theory, ergodic theory, abstract Cauchy problems, convex feasibility problems.

Here is my Curriculum Vitae: CV.pdf.

Current teaching (summer term 2024):

Editorial Work:

Other professional activities:

Wissenschaftliche Gesellschaft an der J.W.Goethe-Universität zu Frankfurt am Main (Member)

PhD Students:



Ulrich Kohlenbach: "Applied Proof Theory: Proof Interpretations and their Use in Mathematics". Springer Monographs in Mathematics, xx+536pp., 2008.



Principal investigator of DFG Project KO 1737/6-1: Proof Mining in Convex Optimization and Related Areas (April 2018-March 2021).

This project has been extended (KO 1737/6-2) until 2024.

Principal investigator of DFG Project KO 1737/5-1: Extraction of effective bounds from proofs based on sequential compactness via logical analysis (Feb 2009-Feb 2013).

This project has been extended (KO 1737/5-2) until November 2016.

Principal investigator of IRTG 1529 `Mathematical Fluid Dynamics' (Tokyo-Darmstadt), 2013-2018.

Member of Deutsch-Russisches Kooperationsprojekt "Berechnungen ueber nichtdiskreten Strukturen: Modelle, Semantik, Komplexität" (DFG 436 RUS 113/850/0-1), 2006-2008.

Member of Deutsch-Südafrikanisches Kooperationsprojekt "From continuity to computability, (DFG/NRF 445 SUA-113/20/0-1), 2007-2009.

Member of APSEM II (IST-2001-38957 Programme of EU.

Principal investigator of project of the Danish Natural Science Research Council (Sagsnr.: 21-02-0474) "Proof Mining: A Logical Approach to Computational Mathematics (2003-2005; stopped in April 2004 due to my move to Germany).

Member of Board of BRICS International PhD School, Dept. of Computer Science, Aarhus University 2000-2004.

Link to the International Research Training Group 1529: Mathematics Fluid Dynamics.


Workshop on Proof Mining 2024, TU Darmstadt, 4-6 September 2024.

Logic Colloquium 2024, U Gothenburg (Sweden), June 24-28, 2024.

Dagstuhl-Seminar 24021, From Proofs to Computation in Geometric Logic and Generalizations, Jan. 7-12, 2024.

Conference on Techniques from Logic in Mathematics, TU Vienna, December 7, 2023.

Oberwolfach Workshop on Mathematical Logic: Proof Theory, Constructive Mathematics, Nov. 12-18, 2023.

5th International Workshop on Cognition: Interdisciplinary Foundations, Models and Applications (CIFMA-2023), Eindhoven University, November 7, 2023.

Working Formal Methods Symposium (FROM 2023), Bucharest, September 21-22, 2023.

4th International Workshop on Cognition: Interdisciplinary Foundations, Models and Applications (CIFMA-2022), Humboldt University, Berlin 27. Sep. 2022.

Applied Proof Theory, U Chieti-Pescara, Italy, August 29-September 2, 2022.

Proof and Computation 2022, May 30- June 2, 2022, Schlehdorf monastery.

Workshop on Nonlinear Functional Analysis and Its Applications in Memory of Professor Ronald E. Bruck, Haifa, Technion, April 4-6, 2022 (online).

New Directions in Computability Theory, CIRM Luminy, March 7-11, 2022.

Dagstuhl Seminar on Geometric Logic, Constructivisation, and Automated Theorem Proving. Schloss Dagstuhl, November 21-26, 2021.

New Frontiers in Proofs and Computations. Institute for Advanced Study in Mathematics, Hangzhou, China, September 12-17, 2021. Held online.

Celebrating 90 Years of Gödel's Incompleteless Theorems. Carl Friedrich von Weizsäcker-Zentrum, Tübingen, July 5-9, 2021.

Logical Perspectives 2021, Moscow, June 7-11, 2021. Held online.

Oberwolfach Workshop on Computability Theory. Mathematical Research Institute Oberwolfach, April 25- May 1, 2021.

Oberwolfach Workshop on Mathematical Logic: Proof Theory, Constructive Mathematics. Mathematical Research Institute Oberwolfach, November 8-14, 2020.

International Conference on Nonlinear Operators, Differential Equations and Applications (ICNODEA 2020), Cluj-Napoca, Romania, September 7-11, 2020. Cancelled.

IECMSA-2020, Skopje, North Macedonia, August 25-28, 2020. Held online.

Anne Troelstra Memorial Event 2020, Amsterdam, March 6, 2020.

ASL Logic Colloquium, August 11-16, 2019, Prague.

Proof, Computation, Complexity. Institut Mittag-Leffler, July 15-19, 2019, Djursholm.

13th International Conference on Fixed Point Theory and Applications (ICFPTA2019), Xinxiang City, China, July 9-13, 2019.

Measuring the Complexity of Computational Content: From Combinatorial Problems to Analysis. Dagstuhl Seminar, Sep. 2-7, 2018.

Kreisel's Interests. On the Foundations of Logic and Mathematics. A conference in honour of Georg Kreisel. Salzburg, Aug. 13-14, 2018.

Conference on Mathematical Logic. Niteroi, Brazil, Aug 10-11, 2018.

International Congress of Mathematicians 2018 (ICM 2018), Rio, August 1-9, 2018.

HIM Trimester Program: Types, Sets and Constructions, HIM Bonn, May 2- Aug 24, 2018.

AAA96 - 96. Arbeitstagung Allgemeine Algebra. TU Darmstadt. June 1-3, 2018.

ASL 2018 North American Annual Meeting. May 16-19, 2018, Macomb (IL), USA.

Computational Approaches to the Foundations of Mathematics. LMU Munich, April 11-13, 2018.

Oberwolfach Workshop on Computability. Mathematical Research Institute Oberwolfach, Jan. 7-13, 2018.

Oberwolfach Workshop on Mathematical Logic: Proof Theory, Constructive Mathematics. Mathematical Research Institute Oberwolfach, November 5-11, 2017.

Autumn school "Proof and Computation", Sep. 23-26, 2017, Herrsching, Germany.

Minisymposium Applied Proof Theory and the Computational Content of Mathematics (as part of the 19th ÖMG Congress and Annual DMV Meeting). Salzburg, September 14, 2017.

12th International Conference on Fixed Point Theory and its Applications. July, 24-28, 2017, Newcastle, New South Wales, Australia.

Computability Theory. Dagstuhl Seminar, February 19-24, 2017.

Algorithmic Randomness Interacts with Analysis and Ergodic Theory. December 4-9, 2016, CMO, Oaxaca, Mexico.

Hilbert Bernays Summer School on Logic and Computation, U Göttingen, July 25-29, 2016.

Intuitionism, Computation, and Proof: Selected themes from the research of G. Kreisel, IHPST Paris, June 10-11, 2016.

CL&C'16 Fifth International Workshop on Classical Logic and Computation. June 23, 2016, Porto, Portugal

PhDs in Logic 2016, Darmstadt, May 9-11.

New Challenges in Reverse Mathematics, January 3-16, 2016, Singapore.

12th International Seminar on Optimization and Related Areas. October 5-9, 2015, Lima, Peru.

Measuring the Complexity of Computational Content: Weihrauch Reducibility and Reverse Analysis. Dagstuhl Seminar, September 20.-25, 2015.

11th International Conference on Fixed Point Theory and Applications, July 20-24, 2015, Galatasaray University, Istanbul, Turkey.

EPSILON 2015: Hilbert's epsilon and tau in Logic, Informatics and Linguistics, University of Montpellier, June 10-12, 2015.

Utrecht Workshop on Proof Theory, April 16-18, 2015.

Oberwolfach Workshop on Mathematical Logic: Proof Theory, Constructive Mathematics. Mathematical Research Institute Oberwolfach, November 16-22, 2014.

WoLLIC 2014, Valpariaso, Chile, Sep. 1-4.

Eleventh International Conference on Computability and Complexity in Analysis, TU Darmstadt, Germany, July 21-24, 2014.

IRTG 1529 Kickoff Meeting, Waseda University, Tokyo, Japan, June 17-18, 2014.

IRTG 1529 Research Seminar "Proof Mining and Nonlinear Analysis", TU Darmstadt, Feb. 26-28, 2014.

IRTG 1529 Winter Seminar and Klausurtagung `Fluids and Snow', Chalet Giersch, La Clusaz, France, Jan. 27-31, 2014.

Royal Society International Scientific Seminar on Computational Interpretations of Mathematical Theorems. Nov. 25-26, 2013, Kavli Royal Society International Centre, Chicheley Hall, Buckinghamshire, UK.

Universality and Homogeneity. Hausdorff Trimester Program September 2 - December 20, 2013, Bonn.

Humboldt-Kolleg "Proof", Bern, Sep. 9-13, 2013.

Honory doctorate for Prof. Dr. Harvey M. Friedman and affiliated workshop, U Gent, Sep. 4-5, 2013.

WoLLIC 2013, TU Darmstadt, August 20-23

Proof Theory in Lisbon, July 19, 2013.

Workshop CSPM Computer Science, Philosophy, Mathematics, Institut de Mathematiques de Toulouse, April 26, 2013.

Types 2013, Toulouse, April 23-26, 2013.

3rd Workshop on Proof Theory and Rewriting. Kanazawa (Japan), March 4-8, 2013.


International Workshop on Fixed Point Theory and Applications, October 11-13, 2012, Istanbul, Turkey.

Third MALOA Training Workshop, University of Oxford, Mathematical Institute, Aug.26 - Sep.1, 2012.

10th International Conference of Fixed Point Theory and its Applications, July 9-15, 2012, Cluj-Napoca, Romania.

15th Latin American Symposium on Mathematical Logic Bogotá, Colombia, June 4-8, 2012.

Workshop on Proof Theory and Computability Theory, Tokyo, Feb. 20-23, 2012.

Oberwolfach Workshop on Computability Theory.Mathematical Research Institute Oberwolfach, February 5-11, 2012.

Oberwolfach Workshop on Mathematical Logic: Proof Theory, Constructive Mathematics. Mathematical Research Institute Oberwolfach, November 6-12, 2011.

Ramsey Theory in Logic, Combinatorics and Complexity. Bertinoro (Italy), May 22-27, 2011.

New Trends in Logic. Conference honoring the Winners of the Kurt Gödel Research Prize Fellowships 2008 and 2011. Austrian Academy of Sciences, Vienna, April 28-29, 2011.

AMS-ASL Special Session on Logic and Analysis. New Orleans, January 6-9, 2011.

Collegium Logicum: Proofs and Structures, Paris, November 8-10, 2010.

Colloquium Logicum 2010 of the DVMLG. WWU Münster, September 22-24, Germany, 2010.

CL&C'10, Third International Workshop on Classical Logic and Computation. Brno, Czech Republic, August 21-22, 2010.

Colloquium PhD's in Logic II. Tilburg University, February 18-19, 2010, The Netherlands.

Reverse Mathematics: Foundations and Applications, University of Chicago, November 6-8, 2009.

Workshop on Ergodic Theory, Queen Mary, University of London London UK, October 30, 2009.

Symposium for Mogens Nielsen's 60th birthday: an Aarhus celebration, Aarhus University, Denmark, October 3-4, 2009.

Maltsev Meeting, Novosibirsk, 24-28 August 2009.

Logic and Mathematics Conference, University of York, 3-7 August 2009.

ASL Logic Colloquium 2009, Sofia, Bulgaria, July 31- August 5, 2009.

Leeds Symposium on Proof Theory and Constructivism, Leeds, UK, July 3-16, 2009.

Computability, Reverse Mathematics and Combinatorics, December 7-12, Banff (Canada), 2008.

Colloquium Logicum 2008, TU Darmstadt, September 10-12. 2008

British Logic Colloquium 2008, September 4-6, 2008, University of Nottingham.

Summer School and Conference Mathematics, Algorithms and Proofs (MAP), August 11-29, 2008, Abdus Salam International Centre for Theoretical Physics, Trieste.

WoLLIC'2008 15th Workshop on Logic, Language, Information and Computation July 1st to 4th, 2008, Edinburgh, Scotland.

Centenary Paul Wolfskehl (with Andrew Wiles), TU Darmstadt, June 30, 2008.

Mathematical Logic: Proof Theory, Constructive Mathematics. Obwerwolfach, April 6-12, 2008

L'Heritage Scientifique de Jacques Herbrand. Herbrand Centenary, February 15, 2008, ENS, Paris.

Workshop "Deduction in Semantics", Stuttgart, 10.-12.10.2007.

Joint Workshop DOMAINS VIII and Computability over Continuous Data Types, Novosibirsk , September 11-15, 2007, Russia.

ASL Logic Colloquium 2007, Worclaw. July 14-19, 2007.

Trimester on methods of proof theory in mathematics. Max Planck Institute for Mathematics, Bonn, March-June 2007.

Joint Mathematics Meeting, AMS-ASL Special Session on Logical Methods in Computational Mathematics, January 5-7, 2007, New Orleans, USA.

2006-2007 ASL Winter Meeting. January 7-8, New Orleans, USA.

Computer Science Logic 2006 (CSL 2006), 25-29 September, 2006, Szeged, Hungary.

Minisymposium on "The use of proof theory in mathematics" within the DMV 2006 Meeting, Bonn 17.-23.09.06.

WoLLIC'2006, 13th Workshop on Logic, Language, Information and Computation July 18-21, 2006, Stanford, California, USA.

Horizons of Truth: Logics, Foundations of Mathematics, and the Quest for Understanding the Nature of Knowledge. Gödel Centenary 2006. An International Symposium Celebrating the 100th Birthday of Kurt Gödel, Vienna, 27.-29. April 2006.

MAP 2006, Castro Urdiales (Spain), 9.1.2006-13.1.2006.

CSL'05, Oxford, UK, 22-25 August 2005.

7th International Conference on Fixed Point Theory and Applications. Guanajuato (Mexico), July 17-23, 2005.

Tagung: Logik und Wissen, Darmstadt 24.-26. Juni 2005

Computability in Europe 2005: New Computational Paradigms ILLC (Amsterdam), June 8-12, 2005

Logic Meeting at UCLA to inaugurate the UCLA Logic Center, February 3-6, 2005.

Computability in Analysis. Kyushu University, Fukuoka, Nov. 22-26, 2004.

COLLOQUIUM LOGICUM 2004, Biannual Meeting of the German Society for Mathematical Logic (DVMLG), September 17 - 19, 2004, Heidelberg (Germany).

Jahrestagung der Deutschen Mathematiker- Vereinigung, Heidelberg, Sept. 12-17, 2004

Sixth International Workshop on Computability and Complexity in Analysis, Wittenberg, Germany, August 16-20, 2004
2003 ASL Annual Meeting University of Illinois at Chicago, Chicago, Illinois June 1-4, 2003
18th IEEE Conference on Computational Complexity, BRICS, University of Aarhus, Denmark, July 7-10, 2003
International Conference of Fixed Point Theory and Applications, Valencia (Spain), July 13-19, 2003
12th. International Congress of Logic Methodology and Philosophy of Science, Oviedo (Spain), August 7-13, 2003 Symposium on `Unusual Effectiveness of Logic in Computer Science', Oviedo 2003 (as part of LMPS)
Fall school of the Logic seminar of the Mathematical Institute of the Academy of Sciences of the Czech Republic, Pec p. Snezkou, Sept. 14-20, 2003.
Workshop on Proof Theory and Algorithms, Edinburgh, March 23-29, 2003
2002 Computability on the Continuuum Seminar, Kyoto, December 14-16, 2002
CSL'02: Annual Conference of the European Association for Computer Science Logic, Edinburgh, September 22-25, 2002
FLoC'02: The 2002 Federated Logic Conference, Copenhagen, Denmark, July 20 -- August 1, 2002
As part of FLoC'02: Seventeenth Annual IEEE Symposium on LOGIC IN COMPUTER SCIENCE (LICS 2002), July 22-25, 2002 Copenhagen.
Bounded Systems and Computational Complexity, Lisbon, June 28-29, 2002.
Meeting of the American Mathematical Society, Columbus (Ohio), September 21-23, 2001
EEF Summer School on Logical Methods, Aarhus, Denmark, June 25-July 6, 2001
International Conference MATHEMATICAL LOGIC, ALGEBRA AND SET THEORY (dedicated to the 100 anniversary of P.S. Novikov), Moscow, August 27-31, 2001
Fourth Workshop on Computability and Complexity in Analysis, September 17-19, 2000, Swansea, Wales
Series of lectures on Constructive Mathematics by D.S. Bridges, Roskilde and Aarhus, Aug 30- Sep 1
Summer School on "Philosophy of Mathematics", University of Roskilde, June 19-32, 2000, Roskilde
Memorial Colloquium for Professor Kurt Schuette and Workshop `Proof and Computation' (November 5-6, 1999)
First St. Petersburg Days of Logic and Computability (May 26-29, 1999)
Reflections: A Symposium Honoring Solomon Feferman on his 70th Birthday (December 11-13, 1998, Stanford University)
BRICS THEME '98: Proofs and Complexity
BRICS Workshop: Proof Theory and Complexity (August 3-7, 1998)