# Of Naturalness and Complexity

## TL;DR

This paper explores the concept of naturalness in complex systems, illustrating how extreme numerical values and cancellations are inherent features, with examples from physics like turbulence and quantum systems.

## Contribution

It proposes that large and small numbers, as well as deep cancellations, are natural in complex systems, linking this idea to problems in physics and the concept of naturalness.

## Key findings

- Large numbers are common in turbulence and quantum systems
- Deep cancellations are natural in complex systems
- Connections to naturalness in high-energy physics are suggested

## Abstract

It is argued that the occurrence of disproportionately ("un-natural") large (or small) numbers, as well as deep cancellations, are comparatively natural traits of the way Nature is geared to operate in most complex systems. The idea is illustrated by means of two outstanding and over-resilient problems in theoretical physics: fluid turbulence and the computation of ground-states of quantum many-body fermion systems. Potential connections with the issue of Naturalness, or lack thereof, in high-energy physics are sketched out.