Fifteenth International Conference on Computability and Complexity in Analysis

August 5-8, 2018, Lake Kochel, Germany
Held in Honour of Klaus Weihrauch's 75th Birthday

Lake Kochel


The conference is concerned with the theory of computability and complexity over real-valued data.

Computability and complexity theory are two central areas of research in mathematical logic and theoretical computer science. Computability theory is the study of the limitations and abilities of computers in principle. Computational complexity theory provides a framework for understanding the cost of solving computational problems, as measured by the requirement for resources such as time and space. The classical approach in these areas is to consider algorithms as operating on finite strings of symbols from a finite alphabet. Such strings may represent various discrete objects such as integers or algebraic expressions, but cannot represent general real or complex numbers, unless they are rounded.

Most mathematical models in physics and engineering, however, are based on the real number concept. Thus, a computability theory and a complexity theory over the real numbers and over more general continuous data structures is needed. Despite remarkable progress in recent years many important fundamental problems have not yet been studied, and presumably numerous unexpected and surprising results are waiting to be detected.

Scientists working in the area of computation on real-valued data come from different fields, such as theoretical computer science, domain theory, logic, constructive mathematics, computer arithmetic, numerical mathematics and all branches of analysis. The conference provides a unique opportunity for people from such diverse areas to meet, present work in progress and exchange ideas and knowledge.

The topics of interest include foundational work on various models and approaches for describing computability and complexity over the real numbers. They also include complexity-theoretic investigations, both foundational and with respect to concrete problems, and new implementations of exact real arithmetic, as well as further developments of already existing software packages. We hope to gain new insights into computability-theoretic aspects of various computational questions from physics and from other fields involving computations over the real numbers.

The conference CCA 2018 is preceded by the conference Computability in Europe (CiE 2018) that takes place in Kiel, in the north of Germany, from July 30 to August 3, 2018.


  • Computable analysis
  • Complexity on real numbers
  • Constructive analysis
  • Domain theory and analysis
  • Effective descriptive set theory
  • Theory of representations
  • Computable numbers, subsets and functions
  • Randomness and computable measure theory
  • Models of computability on real numbers
  • Realizability theory and analysis
  • Reverse analysis
  • Real number algorithms
  • Implementation of exact real number arithmetic

Invited Speakers

Scientific Programme Committee

Organising Committee

Conference Picture

This group picture of CCA 2018 shows some participants:

CCA 2018 Group Picture


You can register for CCA 2018 on the following web page: The registration includes accommodation at the conference centre. There are 41 rooms available that will be assigned on a first-come-first-served basis.

Funding and Sponsoring



Authors are invited to submit 1-2 pages abstracts in PDF format, including references via the following web page: If full versions of papers are already available as technical report or arXiv version, then corresponding links should be added to the reference list. Final versions of abstracts might be distributed to participants in hardcopy and/or in electronic form.


Venue and Accommodation

The conference takes place at the

Georg-von-Vollmar Academy
Schloss Aspenstein
Am Aspensteinbichl 9-11
82431 Kochel am See
Bavaria, Germany

Phone: +49 8851 780
Fax: +49 8851 7823

Kochel am See is beautifully located at Lake Kochel at the edge of the Bavarian Alps, approximately 70 km south of Munich, from where it can easily be reached by train (see below).

Accommodation for most participants of the conference will be available at the Georg-von-Vollmar Academy for a reasonable daily rate. The available rooms will be assigned on a first-come-first-served basis during the registration procedure.


Depending on how you plan to arrive in Kochel, we recommend travelling via the There is a direct reginal train (RB) from Munich main station to Kochel that takes about 1 hour and 10 minutes and starts once an hour. Coming from Munich airport one can change the train for instance at Munich Pasing, but details depend on the schedule. The entire train trip from the airport takes about 2 hours. Please check connections on the railway web page, where you can also book tickets electronically in advance!

Special ticket price: The German railway company offers a limited number of fixed price tickets for trips with the Vollmar academy as destination. The academy can be reached from anywhere in Germany for less than 50 Euro (as long as tickets available):

Please note that this price is not attractive if you travel from Munich (airport), but it might be attractive for those coming from Kiel (CiE 2018).

Important notice: Unfortunately, we learned that the train route from Tutzing to Kochel will be under construction during our conference. Hence, you might find that the railway web page says "train cancelled". What is going to happen is that you will have to leave the train in Tutzing and there will be a substitute bus for each train that continues the trip to Kochel. The bus takes about 20 minutes longer than the train and on the way back it starts about 20 minutes earlier than the train is scheduled. What you need to do is to book the train as if it continues to Kochel and then your ticket will be automatically valid on the substitute bus. There is press release on this matter by German railways (only in German and regarding procedures applied in 2017). Here are more detailed recent information and schedules (in German).

The Georg-von-Vollmar Academy can be reached from the train station Kochel by taxi (approximately 5 minutes, you might have to order it in advance: Phone +49 8851 1315) or by feet (approximately 17 minutes). However, you need to walk slightly up the hill (50 meters).


This schedule might be subject to changes!

CCA Steering Committee

Vasco Brattka, chair (Munich, Germany and Cape Town, South Africa), Peter Hertling (Munich, Germany), Akitoshi Kawamura (Tokyo, Japan), Klaus Weihrauch (Hagen, Germany), Ning Zhong (Cincinnati, USA), Martin Ziegler (Daejeon, Republic of Korea)

Further Information

For further information, please contact