CATSUIT CLIMBING AT THE SOURCE OF IRREVERSIBILITY

Irreversibility, i.e. the lack of invariance of the statistical properties of a system or time series under the operation of time reversal, has attracted the interest of the physics community since the beginning of the scientific study of dynamical systems. This concept has supported the study of many real-world systems, from financial to biological ones. The standard approach has always involved the assessment of the irreversibility of a system, or the quantification of its irreversibility level; on the contrary, no attention has been devoted to the problem of its manipulation. In other words, one may ask the question: given a time-reversible time series, is it possible to modify its values in order to make it irreversible? And, if so, what is the minimum perturbation that enables such change? In this project we will explore the hypothesis that prima facie similar time series may require different perturbation amplitudes to reach irreversibility, or in other words, that they may have different distances to irreversibility; and that such macroscopic property may unveil interesting details about the microscopic dynamics. This distance is here defined as the minimal (in terms of amplitude) perturbation required to achieve a given level of irreversibility; alternative, in a dual representation, as the maximum achievable irreversibility, given a perturbation of fixed amplitude. Such new dynamical concept will be tested against synthetic and biological time series; and an open-source software library for its calculation will be made public.