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Balazs Gyenis

Publications and source records attributed to Balazs Gyenis.

4 recordsLinked to original sources

Trajectory of Probabilities, Probability on Trajectories, and the Stochastic-Quantum Correspondence

The probabilistic description of the time evolution of a physical system can take two conceptually distinct forms: a trajectory of probabilities, which specifies how probabilities evolve over time, and a probability on trajectories, which assigns probabilities to possible histories. A lack of a clear distinction between these two probabilistic descriptions has given rise to a number of conceptual difficulties, particularly in recent analyses of stochastic-quantum correspondence. This paper provides a systematic account of their relationship. We define probability dynamics and stochastic process families together with a precise notion of implementation that connects the two descriptions. We show that implementations are generically non-unique, that every probability dynamics admits a Markovian implementation, and characterize when non-Markovian implementations are possible. We expose fallacies in common arguments for the linearity of probability dynamics based on the law of total probability and clarify the proper interpretation of ``transition matrices'' by distinguishing dynamics-level maps from the conditional probability matrices of implementing processes. We further introduce decomposability as the appropriate general notion of stepwise evolution for (possibly nonlinear) probability dynamics, relate it to divisibility in the linear case -- showing that the two can come apart -- and disentangle both notions from Markovianity and time-homogeneity. Finally, we connect these results to what we call statistical dynamics, in which linearity is indeed physically motivated, and contrast the framework with quantum mechanics.

quant-ph

The Causal Second Law

I argue that if a special science satisfies certain key assumptions that are familiar from physicalist accounts of the special sciences and from physics, then its causal regularities have an associated notion of entropy, and that this causal entropy cannot decrease from a robust cause to its effect. Due to its analogy with the second laws of thermodynamics and statistical physics, I call the latter conclusion the causal second law. In this paper, I clarify the key assumptions, prove the causal second law, give sufficient conditions for causal entropy increase, relate the causal second law to statistical mechanics and thermodynamics, and argue that the reversibility objection does not threaten it. In addition, I claim that the causal second law is compatible with a non-metaphysical understanding of supervenience and the open systems view, argue that it does not imply a causal time arrow, reflect on relaxing the robustness condition, question whether it is necessary to invoke thermodynamics to show that special sciences' time arrows exist, and discuss a transition-relative-frequency-based, special-science-internal characterization of causal regularities.

physics.hist-ph

Empirical structure physicalism and realism, Hempel's dilemma, and an optimistic meta-induction

Motivated by a generalization of Hempel's dilemma, I introduce a novel notion of empirical structure, as well as theory supervenience as a new reductive relationship between theories. One theory supervenes on another theory if the empirical structure of the latter theory refines the empirical structure of the former theory. I then argue that (1) empirical structure physicalism, the thesis that the current special sciences supervene both on current and on future physics, avoids both horns of Hempel's dilemma; (2) in particular, mental theories remain empirically dispensable in the future; (3) empirical structure realism, the thesis that earlier theories of physics supervene on later theories of physics, is supported by an optimistic meta-induction; (4) this optimistic meta-induction can coexist with the well-known pessimistic meta-induction; (5) empirical structure physicalism is appropriately labeled as a type of physicalism; and (6) empirical structure physicalism is compatible with multiple realization. To illustrate the plausibility of empirical structure physicalism, I also briefly address the so-called knowledge argument.

physics.hist-ph

Physical, Empirical, and Conditional Inductive Possibility

I argue that John Norton's notions of empirical, hypothetical, and counterfactual possibility can be successfully used to analyze counterintuitive examples of physical possibility and align better with modal intuitions of practicing physicists. First, I clarify the relationship between Norton's possibility notions and the received view of logical and physical possibility. In particular, I argue that Norton's empirical, hypothetical, and counterfactual possibility cannot coincide with the received view of physical possibility; instead, the received view of physical possibility is a special case of Norton's logical possibility. I illustrate my claims using examples from Classical Mechanics, General Relativity, and Quantum Mechanics. I then arrive at my conclusions by subsuming Norton's empirical, hypothetical, and counterfactual possibilities under a single concept of conditional inductive possibility and by analyzing the types and degrees of strengths that can be associated with it.

physics.hist-ph