arXiv subjects

Baptiste Le Bihan

Publications and source records attributed to Baptiste Le Bihan.

4 recordsLinked to original sources

arXiv2026

String Theory for Metaphysicians

String theory is a minefield for philosophers in terms of conceptual difficulty and mathematical technicality. Presentations aimed at philosophers generally focus on providing precise and technical mathematical descriptions of toy models and inter-theoretical toy derivations to give an idea of what is at play in the field. This presentation takes the opposite approach, filtering out most mathematical considerations to provide an overview of the field, eyes on the ontology. The aim is to provide a compass for metaphysicians to find their way around string theory and the philosophy of string theory. The development of metaphysical arguments based on string theory against the fundamentality of spacetime is deferred to the next chapter.

physics.hist-ph↗

arXiv2025

Holistic Versus Fragmented Multiverses: Empirical Access via Causal and Grounding Signatures

Can multiverse hypotheses ever receive empirical support? Critics argue that multiverse scenarios posit unobservable entities, face severe underdetermination, or fall outside the bounds of science. This chapter challenges that view by offering a naturalistic metaphysical counterpoint to Bayesian approaches, distinguishing fragmented from holistic multiverses. Scientific proposals are almost always holistic: they embed universes within a unifying physical or metaphysical structure that can, in principle, leave empirical signatures inside the universes. I develop a typology of such signatures and show how it applies to leading scenarios from quantum theory, cosmology, and string theory. This framework clarifies why objections such as the `this universe' objection and a newly articulated generalization, the epistemic isolation objection, fail against scientifically motivated multiverses. The upshot is a qualified defence: while fragmented multiverses remain empirically inaccessible, certain holistic multiverses could, in principle, be supported by the same epistemic standards used elsewhere in physics.

physics.hist-ph↗

arXiv2020

What does the world look like according to superdeterminism?

The violation of Bell inequalities seems to establish an important fact about the world: that it is non-local. However, this result relies on the assumption of the statistical independence of the measurement settings with respect to potential past events that might have determined them. Superdeterminism refers to the view that a local, and determinist, account of Bell inequalities violations is possible, by rejecting this assumption of statistical independence. We examine and clarify various problems with superdeterminism, looking in particular at its consequences on the nature of scientific laws and scientific reasoning. We argue that the view requires a neo-Humean account of at least some laws, and creates a significant problem for the use of statistical independence in other parts of physics and science more generally.

physics.hist-ph↗

arXiv2020

String Theory, Loop Quantum Gravity and Eternalism

Eternalism, the view that what we regard locally as being located in the past, the present and the future equally exists, is the best ontological account of temporal existence in line with special and general relativity. However, special and general relativity are not fundamental theories and several research programs aim at finding a more fundamental theory of quantum gravity weaving together all we know from relativistic physics and quantum physics. Interestingly, some of these approaches assert that time is not fundamental. If time is not fundamental, what does it entail for eternalism and the standard debate over existence in time? First, I will argue that the non-fundamentality of time to be found in string theory entails standard eternalism. Second, I will argue that the non-fundamentality of time to be found in loop quantum gravity entails atemporal eternalism, namely a novel position in the spirit of standard eternalism.

physics.hist-ph↗