complexity theory

American  

noun

1. the study of complex and chaotic systems and how order, pattern, and structure can arise from them.

2. the theory that processes having a large number of seemingly independent agents can spontaneously order themselves into a coherent system.

---

complexity theory British  

noun

1. maths the study of complex systems, including subjects such as chaos theory and genetic algorithms

2. computing a field in theoretical computer science dealing with the resources required during computation to solve a given problem

---

complexity theory Scientific  

/ kəm-plĕk′sĭ-tē /

1. See computational complexity

2. Any of various branches of mathematics, physics, computer science, and other fields, concerned with the emergence of order and structure in complex and apparently chaotic systems.

3. See also chaos

---

Example Sentences

This advance was possible because the researchers identified links between the equations used in dipole models and those found in complexity theory.

From Science Daily • Jan. 5, 2026

If it checks out, it solves a number of related problems in pure mathematics, quantum mechanics and a branch of computer science known as complexity theory in one fell swoop.

From Nature • Jan. 15, 2020

At the heart of the paper is a proof of a theorem in complexity theory, which is concerned with efficiency of algorithms.

From Nature • Jan. 15, 2020

The influence of complexity theory, consequently, has been hard to quantify, because its impacts are spread among other fields, rather than in its own cordoned-off territory.

From Slate • Jan. 19, 2016

His library on the second floor of his house in Virginia is lined with rows upon rows of works on complexity theory and military strategy.

From "Blink" by Malcolm Gladwell