The dynamics of higher-order novelties

Gabriele Di Bona, Alessandro Bellina, Giordano De Marzo, Angelo Petralia, Iacopo Iacopini, Vito Latora

The Heaps’ law, which characterizes the growth of novelties, has triggered new mathematical descriptions, based on urn models or on random walks, of the way we explore the world. However, an often-overlooked aspect is that novelties can also arise as new combinations of existing elements. Here we propose to study novelties as n≥1 consecutive elements appearing for the first time in a sequence, and we introduce the nth-order Heaps’ exponents to measure the pace of discovery of novelties of any order. Through extensive analyses of real-world sequences, we find that processes displaying the same pace of discovery of single items can instead differ at higher orders. We then propose to model the exploration dynamics as an edge-reinforced random walk with triggering on a network of relations between items which elvolves over time. The model reproduces the observed properties of higher-order novelties, and reveals how the space of possibilities expands over time along with the exploration process.

Read the full article at: arxiv.org

The Complexity Global School for Emerging Political Economies

Wanted

Brave thinkers willing to explore new ideas about economics, policy, and governance. Early-career scholars and change-makers from civil society and private industry are equally encouraged to apply. 

Who
The December 2023 Complexity Global School (CGS) is a collaboration between the Indian Insitute of Technology Bombay (IITB) in India, the Santa Fe Institute (SFI) in the USA, and the University of the Witwatersrand (Wits) in South Africa. The Complexity Global program is supported by the Emergent Political Economies grant, awarded to SFI in 2022.  

Why
The world is changing. The political and economic paradigms that dominated global affairs in the 20th Century were largely based on linear thinking, and often originated from within disciplinary and cultural silos. The challenges now facing humanity require new ideas. A global perspective is needed; the Indian Institute of Technology Bombay and University of the Witwatersrand are among the top universities in Asia and Africa respectively. A non-linear, or complex, perspective is also needed; for almost 40 years, the Santa Fe Institute has coordinated a network of complexity scholars from top universities around the world. 

More at: www.santafe.edu

Stochastic Thermodynamics of Multiple Co-Evolving Systems—Beyond Multipartite Processes

Farita Tasnim and David H. Wolpert

Entropy 2023, 25(7), 1078

Many dynamical systems consist of multiple, co-evolving subsystems (i.e., they have multiple degrees of freedom). Often, the dynamics of one or more of these subsystems will not directly depend on the state of some other subsystems, resulting in a network of dependencies governing the dynamics. How does this dependency network affect the full system’s thermodynamics? Prior studies on the stochastic thermodynamics of multipartite processes have addressed this question by assuming that, in addition to the constraints of the dependency network, only one subsystem is allowed to change state at a time. However, in many real systems, such as chemical reaction networks or electronic circuits, multiple subsystems can—or must—change state together. Here, we investigate the thermodynamics of such composite processes, in which multiple subsystems are allowed to change state simultaneously. We first present new, strictly positive lower bounds on entropy production in composite processes. We then present thermodynamic uncertainty relations for information flows in composite processes. We end with strengthened speed limits for composite processes.

Read the full article at: www.mdpi.com

In a Flight of Starlings, by Giorgio Parisi

The world is shaped by complexity. In this enlightening book, Nobel Prize winner Giorgio Parisi guides us through his unorthodox yet exhilarating work to show us how. It all starts with investigating the principles of physics by observing the sophisticated flight patterns of starlings. Studying the movements of these birds, he has realized, proves an illuminating way into understanding complex systems of all kinds – collections of everything from atoms to planets to other animals like ourselves.

Along the way, Parisi reflects on the lessons he’s taken from a life in pursuit of scientific truth: the importance of serendipity to the discovery of new ideas, the surprising kinship between physics and other fields of study and the value of science to a thriving society. In so doing, he removes the practice of science from the confines of the laboratory and into the real world. Complexity is all around us – from climate to finance to biology, it offers a unique way of finding order in chaos.

Part elegant scientific treatise, part thrilling intellectual journey, In a Flight of Starlings is an invitation to find wonder in the world around us.

More at: www.penguin.co.uk