Research Projects

Under Review

A paper on the metaphysics of divergence and overlap in the Many Worlds Interpretation of quantum mechanics.

In Progress

Everettian Quantum Gravity (with David Glick)

A project on the prospects for Everettian quantum gravity. 

The Problem of Unlucky Branches 

The MWI entails the existence of low-weight “maverick worlds” or “unlucky branches”: Everettian branches in which the Born rule’s statistical predictions are violated. The existence of such branches is particularly troubling in that some of our best empirical evidence of the quantum mechanics—and by extension, the MWI—comes from experimental confirmation of the Born rule. I begin by demonstrating the tension between these two facts.

On the one hand, if we allow empirical data characteristic of low-weight branches to count as evidence for the MWI, the MWI runs the risk of being problematically insusceptible to ordinary confirmation and disconfirmation by experiment. On the other, if empirical data characteristic of low-weight branches must be taken as evidence against the MWI, then the MWI entails the existence of many observers who are epistemologically condemned through no fault of their methods or principles of empirical inquiry. Such observers are rationally compelled to reject the theory that truthfully describes the universe they inhabit. I then argue that contrary to what many Everettians claim, this consequence is not straightforwardly analogous to situations that arise in non-Everettian theories, and hence, that unlucky branches pose a uniquely troubling epistemological consequence for the MWI.

The Metaphysics and Semantics of Overlap

I defend the overlap view from several arguments posed in the literature. I first consider an argument from Tappenden (2008) that the overlap view cannot secure indexical reference in the present tense. I then examine arguments from Wilson (2011, 2013) that the overlap view cannot account for the truth-values of some future-oriented statements. The third concern I consider is that the overlap theorist cannot give a coherent explanation of subjective uncertainty in an Everettian multiverse. I show that these problems posed for the Everettian overlap view are not unique to EQM: self-locating uncertainty, the semantics of future-directed indexical sentences, and the theory of indexical reference present the same puzzles whether multiplicity arises from Everettian branching or analogous non-quantum cases of fission explored in the metaphysics and personal identity literature. So insofar as we have adequate solutions to these puzzles in non-Everettian contexts, those solutions should extend to EQM.

Given the plausibility that fission cases occur in non-Everettian contexts—e.g., through Parfittian teleporters, lab-grown duplicate humans (e.g., in the film Mickey 17) or mind-uploading (see Chalmers (2014))—it is pertinent to have metaphysics of identity, a semantics, and an account of subjective uncertainty that can accommodate overlapping agents irrespective of issues involving EQM. 

Survival, Identity, and Fusion in Pluribus

This article explores the the metaphysics of persistence, survival, and personal identity in Pluribus (2025). In the show, mass infection via an extraterrestrial virus unifies the overwhelming majority of humanity into a “hive mind”. This is best understood as a case of fusion: an instance in which two or more objects become one. Fusion can be contrasted with fission, in which one object comes to be many. Much of the literature on personal identity and persistence has focused on fission, for example, as in Parfit (1984)’s teletransporter cases. Further, it is commonly argued that paradigmatic fission cases are consistent with agents' survival. In exdurantist (stage-theoretic) terms, the pre-fission temporal parts simply have a plurality of post-fission successors, each of which may have claim to personhood. On the other hand, perdurantists (worm-theorists) typically characterize fission in terms of overlapping temporally extended persons, where two objects overlap just in case they share temporal or spatial parts. Intuitively, these responses should equally be applicable to cases of fusion. Central to the plot of Pluribus, however, is Carol Sturka’s belief—one likely held by many viewers—that the persons infected with the virus have been killed. In other words, Carol holds that fusion does not constitute survival for the pre-fusion entities. If Carol is right, then either (i) cases of fission should similarly not constitute survival, or (ii) there is a surprising asymmetry between fission and fusion in the context of survival and personal identity.

Fine-Tuning and the Plenitudinous Multiverse

A paper on the multiverse response to fine-tuning.