A Non-Probabilistic Model of Relativised Predictability

Abstract

Es werden verallgemeinerte Konzepte von Unberechenbarkeit, insbesondere Komplementarität im Verhältnis zum quantenmechanischen Werteindeterminismus, formalisiert. Besonderen Wert wird dabei auf die Epistemologie gelegt; das heißt die operationellen Mittel und Möglichkeiten eines im System "eingebetteten" intrinsischen Beobachters.

Unpredictability is an important concept throughout physics and plays a central role in quantum information theory. Despite this, little effort has been devoted to studying generalised notions or models of (un)predictability in physics. In this paper, we continue the programme of developing a general, non-probabilistic model of (un)predictability in physics. We present a more refined model that is capable of studying different degrees of ''relativised" unpredictability. This model is based on the ability of an agent, acting via uniform, effective means, to predict correctly and reproducibly the outcome of an experiment using finite information extracted from the environment. We use this model to study the degree of unpredictability certified by different quantum phenomena further, showing that quantum complementarity guarantees a form of relativised unpredictability that is weaker than that guaranteed by Kochen--Specker-type value indefiniteness. We exemplify further the difference between certification by complementarity and value indefiniteness by showing that, unlike value indefiniteness, complementarity is compatible with the production of computable sequences of bits.