Computability in Europe CiE 2026: Timeless Machines / Computability Across Eras
Computability in Europe (CiE) is a conference series interfacing informatics and mathematics. For more information on this conference series, look here. The 22nd edition of CiE will take place at Trier University, July 27.-31., 2026. CiE 2026 will be chaired by Henning Fernau and Vasco Brattka (Munich). During the CiE conference, the Annual Meeting of the Association CiE will take place, as well as the Meeting “Women in Computability.” Registration Link
Registration and Financial Support
Registration fees: We distinguish between full registration and student registration.
- Full registration: Until June 30th: 200 €, from July 1st: 300 €.
- Student registration: Until June 30th: 150 €, from July 1st: 200 €.
Fees cover, among other things, local public transport, meals and coffee breaks at the university, access to rooms. These Fees apply to all conferences and workshops taking place in this week alike.
Funding opportunities for student members of the Association for Symbolic Logic (ASL) are available. Applications should be directed to the Association for Symbolic Logic three months prior to the meeting, following these instructions.
We are very happy to announce that within the framework of the Women in Computability program, we are able to offer some grants to cover the conference registration for junior women researchers who want to participate in CiE 2026. Applications for this grant should be sent to Johanna Franklin at johanna.n.franklinhofstraedu on or before 29 May 2026 and include a short cv (at most 2 pages) and contact information for an academic reference. Preference will be given to junior women researchers who are presenting a paper (including informal presentations) at CiE 2026.
CiE 2026 Colocation with Other Conferences
Organizational Aspects
- The conference will take place on Campus 1 at Trier University.
- There are only very few hotels close to the campus, but it is well connected by bus to the city center.
- The university has no special deals with any hotels, but as hotel prices tend not to be low in Trier, it is advisable to make reservations as early as possible.
- It is not that easy to reach Trier by public transport. Therefore, try to arrive on SUN as otherwise you can be sure to miss nearly all talks on MON (for example). The closest international airport is LUX. Public transport within Luxembourg is free, see http://mobiliteit.lu/.
What to put into your calendar (AoE times)
- Abstract deadline: January 29th, 2026, submissions via Easychair.
- Full Paper deadline: February 3rd, 2026. We expect non-anonymous submissions up to 15 pages in LNCS format, including “everything” apart from a possible appendix (read at the discretion of the PC); alternatively, include a link to an ArXiv version.
- The second round of paper submissions had as deadline March 15th, 2026.
- Registration link opened: April 10th, 2026
- Notification: April 27th, 2026; the notifications have been sent out.
- Deadline for final papers: May 4th, 2026
- Deadline for submission of informal presentations (not to appear in the proceedings): May 17th, 2026 (a slight extension); submissions should be also done via Easychair.
- Notification on informal presentations: June 1st, 2026
Invited Speakers
- Olivier Bournez (Paris, France) [Tutorial Speaker]: Ordinary Differential Equations as a Universal Language for Computability and Complexity: From Polynomial Time to the Hyperarithmetical Hierarchy
- Georg Zetzsche (Kaiserslautern, Germany) [Tutorial Speaker]: General Decidability Results on Unboundedness Problems
- Albert Atserias (Barcelona, Spain): Circuit Complexity Theory in Models of Bounded Arithmetic
- Johanna Franklin (Hempstead, NY, USA): Highness for Scott Rank
- Mathieu Hoyrup (Nancy, France): Presentations of Topological Spaces
- Luca San Mauro (Bari, Italy): Left and Right Effective Symmetries on Baire and Cantor Space
- Francesca Zaffora Blando (Pittsburgh, USA): Algorithmic Randomness and Weak Merging of Opinions
Accepted Contributed Papers
| Giulio Fellin, Sara Negri and Peter Schuster | Nuclear shifts for conservation |
| Arno Pauly | Mergeable represented spaces |
| Nathanael Ackerman, Cameron Freer and Mostafa Mirabi | Computable Cofinal Fraïssé Limits |
| Matthew de Brecht | A note on computable etale spaces |
| Florin Manea, Tina Ringleb, Stefan Siemer and Maximilian Winkler | Efficiently Finding All Shortest Absent Subsequences in a String |
| Mikhail Andreev and Alexander Shen | Bishop’s (up)crossing inequality and lower semicomputable random reals revisited |
| Sam Sanders and Dag Normann | On the computational properties of ambivalent sets and functions |
| Mario Grobler, Nils Morawietz and Silas Cato Sacher | Towards Settling the Complexity of the Lettericity Problem |
| Neil Lutz, Spencer Park Martin and Rain White | Lines in Every Direction with No ee-Random Points |
| Philip Janicki | Tadaki Numbers and Speedability |
| Subin Pulari | On Normality and Equidistribution for Separator Enumerators |
| Anton Lipin and Mikhail Volkov | Adversarial Synchronization and Reset Length |
| Makoto Fujiwara | On the Sigma-hierarchy of the logical principles over intuitionistic predicate logic |
| Ludwig Staiger. | A Polynomial-Time Algorithm for the Automatic Baire Property |
| Lorenzo Carlucci and Oriola Gjetaj | Free Sets, thin sets and Rainbows for barriers |
| John M. Hitchcock, Adewale Sekoni and Hadi Shafei | Counting Random Oracles for the Polynomial-Time Hierarchy and Quantum Complexity Classes |
| Merlin Carl | Complexity of Effective Reductions with Ordinal Turing Machines |
| Julianne Cruz, Sho Glashausser, Xiaoyuan Li and Neil Lutz | Adaptive Multi-Head Finite-State Gamblers |
| Aras Bacho, Svetlana Selivanova and Martin Ziegler | What is a POLYNOMIAL-TIME Computable Square-Integrable Function? |
| Katalin Anna Lázár, Florin Manea, Stefan Siemer and Timo Specht | Self-assembly of Strings and Languages Revisited: Efficient Membership Algorithms |
| Nikolay Bazhenov, Manat Mustafa and Stanislav Yun | On computability of ideal lattices |
| Riccardo Borsetto, Giulio Fellin, Tarmo Uustalu and Cheng-Syuan Wan | Glivenko’s theorem underneath structure |
| Eike Neumann and Margret Tembo | Termination of Real Linear Loops |
| Gero Ellmies and Till Fluschnik | Placing Green Bridges Optimally for Robust Habitat Reconnection |
| Peter Hertling and Leonard Schulte-Michels | Closure Properties of Left NP Real Numbers and NP Real Functions |
| Antonio Nakid Cordero and Isabella Scott | Comparing the Effective Content of Subshifts |
| Lorenzo Carlucci and Giordano Celli | Weihrauch reducibility between Ramsey-type theorems and well-ordering principles at the level of Σ^0_2-induction |
| Patrick Uftring | The more Gödels, the better |
| Sam Sanders | On the Reverse Mathematics of Darboux's supremum principle |
| Reino Niskanen, Igor Potapov and James Topley | Safety and Reachability in k-Control Games on Integer Vector Addition Systems with States |
Special Sessions of CiE 2026
Click on the Special Session titles to learn more ...
Groups and Computability (Laura Ciobanu & André Nies, MON / TUE)
Invited Speakers:
- Arman Darbinyan: tba
- Turbo Ho: Word Problems and the Structure of Computably Enumerable Equivalence Relations
- Emmanuel Rauzy: Residual Properties of Groups in the Continuous Weihrauch Lattice
- Alex Thumm: Solving Equations in Groups
At the Borderline of Universality (Erzsébet Csuhaj-Varjú & Serghei Verlan, MON / TUE)
Invited Speakers:
- Artiom Alhazov: Busy Beaver Problem for Small Deterministic Register Machines
- Matthew Cook: tba
- Gemma De les Coves: Universality and Unreachability in Physics, Mathematics, Computer Science and Slightly Beyond
- Victor Mitrana: Multisets in Reaction Systems
Natural Computation and Bioinformatics (Karel Brinda & Giuditta Franco, MON / TUE)
Invited Speakers:
- Vincenzo Bonnici: tba
- Ragnar Groot Koerkamp: High Throughput Bioinformatics: Pairwise Alignment from Theory to Practice
- David Orellana Martín: Computing with Spikes and Membranes: Computability and Complexity in Spiking Neural P Systems
- Joanna Sułkowska: Novel Knotted Solenoid Fold with Order-Shifted Coil Arrangement
Quantum Computing and Information (Mika Hirvensalo, MON / TUE)
Invited Speakers:
- Jaroslaw Miszczak: Quantum Random Numbers and Where to Find Them
- Abuzer Yakaryilmaz: QIP ⊆ AM(2QCFA)
Learning Theory Meets Computability Theory (Cameron Freer & Sandra Zilles, THU / FRI)
Invited Speakers:
- Dana Fisman: Learning Omega-Regular Languages: A Tour of Learning Results and Canonical Representations
- Kevin Kelly: Topological Foundations for Inductive Learnability
- Alexander Kozachinskiy: Efficient Dimensions for Efficient Learning and Generation
- Ruth Urner: CPAC: A Brief Tale about a New Paradigm of Learnability
HaPoC (History and Philosophy of Computing): New French Philosophy of Computing (Hajo Greif, THU / FRI)
Invited Speakers:
- Thierry Coquand (will deliver an interview with Paula Quinon)
- Paula Quinon: The New French School of Philosophy of Computing
- Thomas Seiller: Mathematical Informatics: Algorithms
- Loïc Colson: An Introduction to Functional Systems
Program Committee of CiE 2026
- Verónica Becher, Universidad de Buenos Aires, Argentina
- Paola Bonizzoni,Università di Milano-Bicocca, Italy
- Vasco Brattka (PC co-chair), Universität der Bundeswehr Munich, Germany
- Rod Downey, Victoria University of Wellington, New Zealand
- Damir D. Dzhafarov, University of Connecticut, USA
- Henning Fernau (PC co-chair), Trier University, Germany
- Gilda Ferreira, Universidade Aberta, Portugal
- Lorenzo Galeotti (SC chair), University of Amsterdam, The Netherlands
- Daniel Graça, University of Algarve, Portugal
- Gabriel Istrate, University of Bucharest, Romania
- Jarkko Kari, University of Turku, Finland
- Lila Kari, University of Waterloo, Canada
- Akitoshi Kawamura,Kyoto University, Japan
- Takayuki Kihara, Nagoya University, Japan
- Alberto Marcone, Università di Udine, Italy
- Elvira Mayordomo, Universidad de Zaragoza, Spain
- Wolfgang Merkle, Universität Heidelberg, Germany
- Cécilia Pradic, Swansea University, UK
- Giuseppe Primero, University of Milan, Italy
- Paul Shafer, University of Leeds, UK
- Tomasz Steifer, Polish Academy of Sciences
- Frank Stephan, National University of Singapore
- Manlio Valenti, Swansea University, UK
- Serghei Verlan, University Paris Est Créteil, LACL, France
- Andreas Weiermann, Ghent University, Belgium
- Tomoyuki Yamakami, Fukui University, Japan
List of Topics of CiE 2026 (non-exclusive)
- Algorithmic Information Theory
- Algorithmic Learning Theory
- Algorithmic Measure Theory
- Algorithmic Randomness
- Analog Computation Models
- Automata Theory
- Biocomputing
- Category Theory
- Complexity Theory
- Complex Systems
- Computability
- Computable Analysis
- Computational Biology
- Decidability
- Descriptive Set Theory
- Formal Languages
- History of Computing
- Mathematical Logic
- Natural Computing
- Philosophy of Computation
- Proof Theory
- Quantum Computation
- Recursion Theory
- Reverse Mathematics
Responsible for the contents of this page: Henning Fernau.