Complexities: An Open Access Journal for the Field of Complex Systems

On behalf of the MDPI Editorial Board and Staff, I am pleased to announce the launch of Complexities (ISSN: 3042-6448) [1], a new, peer-reviewed, open-access journal dedicated to exploring and advancing our understanding of complex systems and their applications in a wide range of fields. This inaugural issue marks the beginning of an ambitious journey that will entail delving into the principles, methodologies, and phenomena that define the intricate and interconnected systems that shape our world.

Complex systems are everywhere, embedded in natural and artificial processes—from ecosystems and social networks to economic structures and artificial intelligence. These systems are defined by their interconnectivity, non-linear behaviors, and emergent properties, where the whole often exceeds the sum of its parts. With this in mind, Complexities aims to serve as a global hub for collaboration, bringing together researchers from diverse disciplines to advance fundamental theoretical studies and practical, real-world applications of complexity science.

Our mission is to provide a platform for publishing innovative research in areas such as complex systems theory, network science, non-linear dynamics, adaptive systems, computational complexity, and quantum complexity. By bridging the gap between empirical research, theoretical insights, and practical solutions, Complexities aims to uncover the fundamental principles behind complex phenomena and apply them to address pressing challenges in technology, society, and the environment.

Thanks to the emergence of advanced computational tools and the availability of extensive datasets, researchers now enjoy opportunities like never before to study complexity. From modeling emergent behaviors and simulating multi-agent interactions to discovering hidden patterns in complex networks, the possibilities are endless. At the same time, global issues—such as pandemics and economic disruptions—underscore the urgency of interdisciplinary collaboration and the necessity for innovative approaches.

Complexities seeks to embrace these challenges by welcoming contributions that offer diverse perspectives and methodologies. By showcasing the full scope of complexity science, we aim to inspire new discoveries and applications that benefit society in its entirety. The 21st century is often called the “century of complexity”, a sentiment reflected in recent Nobel Prize awards (2021 and 2024) that have been recognized for work in related fields.

As we embark on this exciting journey, we invite everyone to join us in this challenge. Whether your research focuses on the mathematical foundations of complexity, solving practical problems, or advancing quantum or computational complexity, Complexities is here to provide a platform for sharing your discoveries.

We are deeply committed to fostering an inclusive and collaborative research community and to publishing work that reflects the richness and diversity of complexity science.

Welcome to Complexities—the challenge starts now!