Search arXivSearch

arXiv · 2309.06595

Points of convergence -- music meets mathematics

Abstract

"Phase-locking" is a fundamental phenomenon in which coupled or periodically forced oscillators synchronise. The Arnold family of circle maps, which describes a forced oscillator, is the simplest mathematical model of phase-locking and has been studied intensively since its introduction in the 1960s. The family exhibits regions of parameter space where phase-locking phenomena can be observed. A long-standing question asked whether "hyperbolic" parameters~-- those whose behaviour is dominated by periodic attractors, and which are therefore stable under perturbation~-- are dense within the family. A positive answer was given in 2015 by van Strien and the author, which implies that, no matter how chaotic a map within the family may behave, there are always systems with stable behaviour nearby. This research was a focal point of a pioneering collaboration with composer Emily Howard, commencing with Howard's residency in Liverpool's mathematics department in 2015. The collaboration generated impacts on creativity, culture and society, including several musical works by Howard, and lasting influence on artistic practice through a first-of-its-kind centre for science and music. We describe the research and the collaboration, and reflect on the factors that contributed to the latter's success.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Lasse Rempe. 2023-09-12. Points of convergence -- music meets mathematics. https://doi.org/10.1007/978-3-031-48683-8_33

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Toric Differential Inclusions and a Proof of the Global Attractor Conjecture

The global attractor conjecture says that toric dynamical systems have a globally attracting point (up to linear conservation relations), or equivalently, complex balanced systems have a globally attracting point within each stoichiometric compatibility class. A proof of this conjecture implies that a large class of nonlinear dynamical systems on the positive orthant have very simple and stable dynamics. The conjecture originates from the 1972 breakthrough work by Fritz Horn and Roy Jackson, and was formulated in its current form by Horn in 1974. Toric dynamical systems can be embedded into toric differential inclusions. We show that each bounded positive solution of a toric differential inclusion is contained in an invariant region that prevents it from approaching the boundary of the positive orthant. We use this result to prove the global attractor conjecture. In particular, it follows that all detailed balanced mass action systems and all deficiency zero weakly reversible systems have the global attractor property.

math.DS

Pinched Arnol'd tongues for Families of circle maps

We prove that generically for a family of circle maps \begin{equation*} f_{b, ω} (x) = x + ω+ b\, ϕ(x) \end{equation*} with $ϕ$ a piecewise linear forcing with $k>2$ breakpoints there is no pinching in any of its Arnol'd tongues. This is in contrast to a theorem of Campbell, Galeeva, Tresser, and Uherka who showed that with two break points there are always multiple pinchpoints in its rational tongues. We also prove that the absence of pinching is generic for Lipschitz and $C^r$ ($r>0$) forcing. The family $f_{b, ω}$ is used as a simple model for a periodically forced oscillator. The rational tongue $T_{p/q}$ represents parameter values where the system is mode-locked into a $p/q$-periodic response. The pinching of the tongues to a point represents parameter values where the system's periodic response is unstable to all perturbations in the frequency parameter $ω$. The theorems in this paper show that typically this type of instability does not occur in the families under consideration.

math.DS

Mostly nonuniformly sectional expanding systems

We introduce the notion of \emph{mostly nonuniform sectional expanding} (MNUSE) for singular flows which encompasses the notions of sectional hyperbolicity, asymptotically sectional and multisingular hyperbolicity. We construct examples of a vector field of class $C^r, r \ge 1$, whose flow exhibits a nonuniformly sectional hyperbolic set satisfying MNUSE, which is neither sectional hyperbolic nor asymptotically sectional hyperbolic. We obtain sufficient conditions for the existence of physical/SRB measures for asymptotically sectionally hyperbolic attracting sets with any finite codimension, extending the codimension two case. We provide examples of such attractors, either with non-sectional hyperbolic equilibria, or with sectional hyperbolic equilibria of mixed type, i.e., with a Lorenz-like singularity together with a Rovella-like singularity in a transitive set. These are higher-dimensional versions of contracting Lorenz-like attractors (also known as Rovella-like attractors) to which we apply our criteria to obtain a physical/SRB measure with full ergodic basin. We also adapt the previous examples to obtain higher codimensional (i.e. with central direction of dimension greater than $2$) nonuniformly sectional expanding attractors.

math.DS