I present and defend a new ontology for quantum theories (or ``interpretations'' of quantum theory) called Generative Quantum Theory (GQT). GQT postulates different sets of features, and the combination of these different features can help generate different quantum theories. Furthermore, this ontology makes quantum indeterminacy and determinacy play an important explanatory role in accounting for when quantum systems whose values of their properties are indeterminate become determinate. The process via which determinate values arise varies between the different quantum theories. Moreover, quantum states represent quantum properties and structures that give rise to determinacy, and each quantum theory specifies a structure with certain features. I will focus on the following quantum theories: GRW, the Many-Worlds Interpretation, single-world relationalist theories such as Relational Quantum Mechanics, Bohmian Mechanics, hybrid classical-quantum theories, and Environmental Determinacy-based (EnD) Quantum Theory. I will argue that GQT should be taken seriously because it provides a series of important benefits that current widely discussed ontologies lack, namely, wave function realism and primitive ontology, without some of their costs. For instance, it helps generate quantum theories that are compatible with relativistic causality, such as EnD Quantum Theory. Also, GQT has the benefit of providing new ways to compare and evaluate quantum theories, which may lead to philosophical and scientific progress.
I present and defend a new ontology for quantum theories (or ``interpretations'' of quantum theory) called Generative Quantum Theory (GQT). GQT postulates different sets of features, and the combination of these different features can help generate different quantum theories. Furthermore, this ontology makes quantum indeterminacy and determinacy play an important explanatory role in accounting for when quantum systems whose values of their properties are indeterminate become determinate. The process via which determinate values arise varies between the different quantum theories. Moreover, quantum states represent quantum properties and structures that give rise to determinacy, and each quantum theory specifies a structure with certain features. I will focus on the following quantum theories: GRW, the Many-Worlds Interpretation, single-world relationalist theories such as Relational Quantum Mechanics, Bohmian Mechanics, hybrid classical-quantum theories, and Environmental Determinacy-based (EnD) Quantum Theory. I will argue that GQT should be taken seriously because it provides a series of important benefits that current widely discussed ontologies lack, namely, wave function realism and primitive ontology, without some of their costs. For instance, it helps generate quantum theories that are compatible with relativistic causality, such as EnD Quantum Theory. Also, GQT has the benefit of providing new ways to compare and evaluate quantum theories, which may lead to philosophical and scientific progress.
In this dissertation, I propose two frameworks to address some important scientific and philosophical issues with quantum theory (QT). First, I propose Environmental Determinacy-based Quantum Theory (EnDQT) and argue that contrary to the other well-known quantum theories, it has the great benefit of being a local, non-relational, and non-superdeterministic/non-retrocausal "interpretation" of quantum theory, or quantum theory (QT). EnDQT has the benefit of being conservative, not modifying the fundamental equations of QT, and, in principle, allowing arbitrary systems to be placed in a coherent superposition for an arbitrary amount of time. Also, EnDQT is able to give a local causal explanation of quantum correlations. Via EnDQT, I also argue that i) QT is local in the sense of not being in conflict with relativity but without the need to adopt a relationalist, a superdeterminist, or a retrocausal approach. I also argue that ii) the notorious measurement problem can be addressed without modifying the quantum formalism, adding hidden variables, or adopting relationalism. Second, I propose Generative Quantum Theory (GQT) as a new ontology for quantum theories and show how it can be implemented via GRW, the MWI and single-world relationalist views, Bohmian Mechanics, hybrid classical-quantum theories, and EnDQT. I also distinguish it from the most discussed ontologies for quantum theories, namely, wavefunction realism and primitive ontology, and argue that it has certain benefits that they lack without some of their costs, such as non-locality. Due to the overall benefits of GQT compared with these widely debated ontological frameworks, and given that GQT, contrary to these frameworks, considers the wavefunction more like a predictor and that quantum indeterminacy plays an important explanatory role, I will argue that iii) the wavefunction is more like a predictor for different possibilities rather than a law or a field in a multidimensional space, and that iv) quantum indeterminacy plays a key explanatory role instead of a derivative role in order to understand QT.
I propose a novel interpretation of quantum theory, which I will call Environmental Determinacy-based (EnDQT). In contrast to the well-known interpretations of quantum theory, EnDQT has the benefit of not adding non-local, superdeterministic, or retrocausal hidden variables. Also, it is not in tension with relativistic causality by providing a local causal explanation of quantum correlations. Furthermore, measurement outcomes don't vary according to, for example, systems or worlds. It is a conservative QT in the sense that, unlike theories such as spontaneous collapse theories, no modifications of the fundamental equations of quantum theory are required to establish when determinate values arise. Moreover, in principle, arbitrary systems can be in a coherent superposition for an arbitrary amount of time. According to EnDQT, at a certain stage of the evolution of the universe, some systems acquire the capacity to have and give rise to other systems having determinate values through an indeterministic process. Furthermore, this capacity propagates via local interactions between systems. When systems are isolated from others that have this capacity, they can, in principle, evolve unitarily indefinitely. EnDQT may provide payoffs to other areas of physics and their foundations, such as cosmology, via the features of the systems that start the chains of interactions.
The received view in foundations and philosophy of physics holds that if we reject supplementing quantum theory (QT) with certain hidden variables and consider that unitary QT is correct and universal, we should adopt a relationalist interpretation of QT. Relationalist interpretations relativize measurement outcomes to, for example, worlds, systems, agents, or reference frames. It includes the Many-Worlds Interpretation, Relational Quantum Mechanics, and QBism. These interpretations have potential costs connected with their relationalism that make them unattractive. Thus, if there exists a non-relational non-hidden variable universal intepretations of QT, it should be taken seriously. I will present an interpretation of this kind called Environmental Determinacy-based or EnD Quantum Theory (EnDQT), which goes beyond relationalism and the received view. EnDQT circumvents relationalism by constructing an account of indeterminate and determinate values and underlying quantum properties that is not relational while maintaining unitary non-hidden variable universal QT. In situations where a relationalist assumes that measurement outcomes are relativized, such as in the extended Wigner's friend scenarios, according to EnDQT there aren't determinate outcomes but systems with non-relational indeterminate values. In this approach, determinate values arose at some point in time through certain systems and persist due to them via certain interactions represented by certain networks. When there is isolation from the rest of the systems that belong to these networks, such as inside the friend's lab in the extended Wigner's friend scenarios, indeterminate values non-relationally arise inside. I will discuss other independent good reasons for adopting EnDQT, including providing a local causal explanation of Bell correlations and novel empirical posits represented by these networks.
Abstract Of the many ways of getting at the core of the weirdnesses in quantum mechanics, there’s one which traces back to Schrödinger’s seminal 1935 paper, and has to do with the apparent fuzzy nature of the reality described by the formalism through the wavefunction ψ ψ . This issue, which I will be calling the Determinacy Problem, is distinct from the standard measurement problem of quantum mechanics, despite Schrödinger himself ends up conflating the two. I will argue that the Determinacy Problem is an exquisitely philosophical problem, for as it is standard when facing any phenomenon which appears to have indeterminate or fuzzy characteristics, the solutions available are to either blame the deficiencies of our language, or our lack of knowledge, or to blame the world itself. These three attitudes can already be found in the literature on quantum mechanics, either explicitly or implicitly, and they appear to motivate three very distinct research programs: high-dimensional realism, primitive ontology, and quantum indeterminacy.
Abstract Many features of quantum mechanics (QM) suggest that, at the microscopic level, objects sometimes fail to determinately instantiate their properties. In recent years, many have argued that this phenomenon indicates the existence of an ontological kind of indeterminacy, often called metaphysical indeterminacy , which is supposed to affect the ontology of QM. As insisted by Glick ('Against Quantum Indeterminacy, 2017, Thought), however, once we look at the major realist approaches to QM we learn that the indeterminacy disappears from the description of the world at its most fundamental level. This absence might be taken as a good reason for adopting some form of eliminativism towards quantum mechanical indeterminacy. The aim of this paper is to distinguish three ways of defending eliminativism, and to argue that none of them eventually succeeds. The upshot is that QM does in fact suggest the existence of metaphysical indeterminacy, although only as an emergent phenomenon.
The dissertation is a defense of the following conditional claim: if there are objective collapses of the wavefunction, then the future is genuinely open. Although this is no radically new idea, the strategy I shall use to defend it is a new one. It proceeds in two main steps. First, building upon the recent literature on metaphysical indeterminacy in quantum mechanics, I argue for the view that systems in superposition have be interpreted as objectively indeterminate state of affairs. Second, I propose an alternative way to think of openness, according to which the future is open as of t, if and only if there is an indeterminate state of affair S at t, and S becomes determinate at t? (with t? later than t). To argue for the second step, I will give an analysis of the objective collapses of the wavefunction as the becoming determinate of previously indeterminate systems. Furthermore, in developing my arguments, I will also make some remarks concerning the ontology of objective collapse interpretations of quantum mechanics, the issue of whether metaphysical indeterminacy can be at some derivate level of reality, and the possibility of the openness of the future being an emergent phenomenon.