About this Research Topic
After the birth of Quantum Physics, the problem of relations with the classical world took the form of a search for a "classical limit". Today the question is even more complex and involves the same "ontology" of quantum reality and its manifestations.
As we test the Standard Model (SM) and inquire about its “under” and “beyond” features, on the threshold of Quantum Gravity (QG), the foundational problems of Quantum Mechanics (QM) become more and more urgent and less and less dependent on philosophical matters.
We aim to understand what the origin and the role of quantum behavior is as well as defining the applicability criteria. Is QM really the “bottom of the world”? We use it traditionally correctly at the atomic scale, but are these practices reliable for QG? We propose to re-examine the Bohr-Einstein debate in a new perspective.
The key concept is the introduction of “emergence”, a long-studied concept in Complex Systems Physics, which suggests a new way to deal the relation between the classical and quantum domains.
There is a wide range of theoretical ideas which are relevant here: from God's computer by G. t'Hooft that solves the quantum dice with local cellular automata at finite information on the Plank scale to the God's Bubble Bath approaches hypothesizing entropic dynamics. There are also researchers who distinguish correlations from casual signals, so deepening the peculiar meaning of the quantum case (God's Keystream Generator). The Einstein space-time itself is questioned using “superfluid” emergent models, ideally linked to the Sacharov's work, up to the event notion. The Reality could not be explicitly manifest anywhere and the classical reality could be suspended on a cloud of quantum possibilities. This version of extreme emergence with a fine algebraic charm finds its roots in the last works by D. Bohm.
The Quantum → Classical approaches, implying local emergence from the non-local, and the reverse ones, Classical → Quantum, where non-local and entangled behaviors are coarse grain effects of essentially local processes, need to reconsider closely the concept of information. Is Quantum Information really captured by Turing's grid, as quantum computing theoreticians maintain? Or is it necessary to recover in formalism the ideas of Bohm and Hiley on active information? How does all this link to the idea of a radical discretization of time space at Planck Scale? How does the smoothness of general relativity space time emerge? As it is known, Quantum Information and non-local correlations can be described by time reversal models. Then, even the concept of time, on which usual dynamical approaches are based upon, is subject to new conceptual changes as well as the concepts in cosmology and particle physics.
The purpose of this Research Topic is to stimulate a reflection on these fundamental aspects and their correlations. Possible themes include, but are not limited to:
• Quantum/Classical limit
• QM Interpretations
• QM as emergence
• Arrow of time in Classical and Quantum Physics
• Approaches in Quantum concept of Time: Discrete and continuous Information in Fundamental Physics
• Quantum Cosmology
Keywords: Emergence of time, Quantum Information, Classical-Quantum Transitions Theories, QM Interpretations, Time in QM
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