Complexity characterises the behaviour of a system or model whose components interact in multiple ways and follow local rules, meaning there is no reasonable higher instruction to define the various possible interactions.
Computational complexity theory focuses on classifying computational problems according to their inherent difficulty, and relating these classes to each other. A computational problem is a task solved by a computer. A computation problem is solvable by mechanical application of mathematical steps, such as an algorithm.
A complex system is a system composed of many components which may interact with each other. Examples of complex systems are Earth's global climate, organisms, the human brain, infrastructure such as power grid, transportation or communication systems, social and economic organizations, an ecosystem, a living cell, and ultimately the entire universe.
Stephen Arthur Cook, is an American-Canadian computer scientist and mathematician who has made major contributions to the fields of complexity theory and proof complexity. He is a university professor at the University of Toronto, Department of Computer Science and Department of Mathematics.
Robert Marshall Axelrod is an American political scientist. He is Professor of Political Science and Public Policy at the University of Michigan where he has been since 1974. He is best known for his interdisciplinary work on the evolution of cooperation, which has been cited in numerous articles. His current research interests include complexity theory, international security, and cyber security. Axelrod is a member of the Council on Foreign Relations. Axelrod is also a Senior Fellow at ARTIS International.
Andrew Chi-Chih Yao is a Chinese computer scientist and computational theorist. He is currently a Professor and the Dean of Institute for Interdisciplinary Information Sciences (IIIS) at Tsinghua University. Yao used the minimax theorem to prove what is now known as Yao's Principle.
Combinatorial game theory has several ways of measuring game complexity. This article describes five of them: state-space complexity, game tree size, decision complexity, game-tree complexity, and computational complexity.
Nihon University, abbreviated as Nichidai (日大), is a private research university in Japan. Yamada Akiyoshi, the Minister of Justice, founded Nihon Law School, currently the Department of Law, in October 1889.
Tokyo Institute of Technology is a national research university located in Greater Tokyo Area, Japan. Tokyo Tech is the largest institution for higher education in Japan dedicated to science and technology, and is generally considered to be one of the most prestigious universities in Japan.
Quantum information science is an area of study based on the idea that information science depends on quantum effects in physics. It includes theoretical issues in computational models as well as more experimental topics in quantum physics including what can and cannot be done with quantum information. The term quantum information theory is sometimes used, but it fails to encompass experimental research in the area and can be confused with a subfield of quantum information science that studies the processing of quantum information.
Nitin Saxena is an Indian scientist in mathematics and theoretical computer science. His research focuses on computational complexity.
Christos Harilaos Papadimitriou is a Greek theoretical computer scientist, and professor of Computer Science at Columbia University.
Tokyo University of Science, formerly "Science University of Tokyo" or TUS, informally Rikadai (理科大) or simply Ridai (理大) is a private research university located in Shinjuku, Tokyo, Japan.
Complexity theory and organizations, also called complexity strategy or complex adaptive organizations, is the use of the study of complexity systems in the field of strategic management and organizational studies.
Avi Wigderson is an Israeli mathematician and computer scientist. He is professor of mathematics at the Institute for Advanced Study in Princeton. His research interests include complexity theory, parallel algorithms, graph theory, cryptography, distributed computing, and neural networks.
Seinosuke Toda is a computer scientist working at the Nihon University in Tokyo. Toda earned his Ph.D. from the Tokyo Institute of Technology in 1992, under the supervision of Kojiro Kobayashi. He was a recipient of the 1998 Gödel Prize for proving Toda's theorem in computational complexity theory, which states that every problem in the polynomial hierarchy has a polynomial-time Turing reduction to a counting problem.
Scott Joel Aaronson is an American theoretical computer scientist and David J. Bruton Jr. Centennial Professor of Computer Science at the University of Texas at Austin. His primary areas of research are quantum computing and computational complexity theory.
Paul Michael Béla Vitányi is a Dutch computer scientist, Professor of Computer Science at the University of Amsterdam and researcher at the Dutch Centrum Wiskunde & Informatica.
Meiji Maru (明治丸) is a Japanese sailing ship that serves as a museum ship in Tokyo. It is displayed at the Etchujima Campus of the Tokyo University of Marine Science and Technology.
