Sixth International Conference on Computability and Complexity in Analysis

August 18-22, 2009, Ljubljana, Slovenia



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

Tutorial Speaker

Scientific Programme Committee

Organizing Committee

Faculty of Mathematics and Physics
University of Ljubljana and
Institute of Mathematics, Physics and Mechanics.


The conference poster is available here:

CCA 2009 Poster

Venue, Accommodation, Traveling & Registration

Further information on local arrangements and registration are 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 should be prepared using the LNCS stylefile of Springer Verlag; see


A technical report including the accepted papers will be distributed at the conference. An electronic proceedings volume will appear in the DROPS series of Schloss Dagstuhl. It is planned to publish a special issue of some journal dedicated to CCA 2009 after the conference.


New submission deadline: May 18, 2009
Notification of authors: June 15, 2009
Final version: July 13, 2009

CCA Steering Committee

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

Further Information

For further information, please contact