Further Detail of Time and Temporal Relationalism in Quantum Theory

Sean Gryb, Karim P. Y. Thébault

Áron Szücs

The paper proposes the theory of temporal extension for fundamental particles as a key to intuitively interpret and understand quantum symmetries and related quantum and relativistic phenomena. While space-time as a principal world view is accepted and utilized in fundamental theories, certain traditional concepts of time have not been challenged before. Such a conception is the view that physical objects can only have a point like feature on the time line. When introducing a more space like quality of time, which allows the temporal extension for physical objects and particles, a fundamentally new world view arises. In this view quantum symmetries and certain relativistic phenomena become more intuitive to describe and deal with and realism gets a new definition. As a result the temporal length theory also offers to eliminate the tension between the nonlocality of quantum physics and the locality of relativistic phenomena. The paper provides a detailed description of the theory.

Henry Mehlberg, Robert S. Cohen

Nuel Belnap, Thomas Müller, Tomasz Placek

This monograph presents the first detailed exposition of the formal theory of Branching Space-Times. The theory presented here by Nuel D. Belnap, Thomas Muller, and Tomasz Placek describes how real possibilities can play out in our spatio-temporal world. In our world, some things that are really possible in Cleveland are not really possible in San Francisco; other things were really possible in 1988 but are not really possible in 2021. The authors develop a rigorous, relativity-friendly theory of indeterminism as a local and modal concept, demonstrating that our world contains events with alternative possible outcomes. The book is divided into two parts. The first contains the exposition of the theory, including detailed proofs. The second contains three applications of Branching Space-Times in metaphysics and philosophy of science, focusing on the use of Branching Space-Times to represent pertinent forms of indeterminism in each area. Some specific applications include a formal analysis of modal correlations and of causation and a rigorous theory of objective single-case probabilities, intended to represent degrees of possibility. The authors link their theory to current physics, investigating how local and modal indeterminism relates to issues in the foundations of physics, particularly in quantum non-locality and spatio-temporal relativity. They also relate the theory to philosophy of time, showing how it may be used to explicate the dynamic concept of the past, present, and future based on local indeterminism. The Branching Space-Times theory has been in development over the past 25 years. This volume provides a much needed first systematic and comprehensive book-length exposition of both the theory and its applications.

Charis Anastopoulos, B. L. Hu, Ntina Savvidou

Abstract We present our program for the development of quantum informational concepts in relativistic systems in terms of the unequal-time correlation functions of quantum fields. We employ two formalisms that provide the basis for further developments. (i) The Quantum Temporal Probabilities (QTP) Method for quantum field measurements and (ii) the Closed-Time-Path (CTP) formalism for causal time evolutions. We present the main ideas of QTP and we show how it relates to the CTP formalism, allowing us to express concepts of measurement theory in terms of path-integrals. We also present many links of our program to non-equilibrium quantum field theories. Details can be found in a recent paper by the authors [1].

Henry Mehlberg