Fifth International Conference on Computability and Complexity in Analysis

Held in Honor of Klaus Weihrauch's 65th Birthday
August 21-24, 2008, Hagen, Germany

Foto: FernUniversität Hagen


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.

Invited Speakers

Scientific Program Committee

Organizing Committee


The conference poster is available here:

CCA 2008 Poster


The provisional programme of the conference is available here:

CCA 2008 Program

Group Picture

Some participants of CCA 2008


For information on registration and fees, please go to the following page:

CCA 2008 Registration.
It is planned to have a registration desk at the Arcadeon

Venue & Accommodation & Travelling

The venue for CCA 2008 talks is the meeting center Arcadeon, Lennestraße 91, 58093 Hagen. Suggestions for accommodation can be found here:

Information on travelling is available here:



Authors are invited to submit a PDF version of an extended abstract (typically 10-12 pages) on the following web page:

These extended abstracts have to be prepared with ENTCS style files.


Accepted papers will be published as CCA 2008 proceedings in Electronic Notes in Theoretical Computer Science (ENTCS). In addition, a printed version (as a technical report) will be available at the conference.

It is planned to publish a special issue of some journal dedicated to CCA 2008 after the conference.


Submission deadline: May 26, 2008
Notification of authors: June 23, 2008
Final version: July 21, 2008

CCA Steering Committee

Vasco Brattka (Cape Town, South Africa), Peter Hertling (Neubiberg, Germany), Ker-I Ko (Stony Brook, USA), Klaus Weihrauch, chair (Hagen, Germany), Ning Zhong (Cincinnati, USA)

Further Information

For further information, please contact