Antonio Vassallo

PhD Student

Epistemology and Philosophy of Science
University of Lausanne
Department of Philosophy
CH-1015 Lausanne

Analytic Philosophy
University of Warsaw
Institute of Philosophy
Krakowskie Przedmieście 3
00-927 Warsaw

antonio.vassallo@unil.ch

11.02.2012 "The Metaphysics of Quantum Gravity"
(Lucerne Graduate Conference 2012, Universität Luzern).

06.04.2011 “Time and Causation in Quantum Gravity”
(Séminaire de recherches actuelles en philosophie des sciences, Université de Lausanne).

30.03.2011 “Spacetime and Matter in Five Dimensions”
(Séminaire de recherches actuelles en philosophie des sciences, Université de Lausanne).

Research interests

• Philosophy of physics (in particular philosophy of space and time, foundational issues in general relativity and quantum gravity)
• Philosophy of science
• Metaphysics
• Epistemology

“Metaphysics of Quantum Gravity” project's abstract

The project’s aim is to investigate some major conceptual issues in spacetime theories with a particular focus on the general theory of relativity and the canonical approach to quantum gravity. It will be given a general sketch of a spacetime theory which accommodates both classical and quantum approaches to gravity. The final scope of the project is to develop a realist position grounded in scientific essentialism which is able to address fundamental metaphysical issues such as, for example, the age old debate between substantivalism and relationism.

Project's current achievements:

1. It has been given a formal definition of spacetime theory general enough to include all physical accounts of gravity, from Newtonian theory to modern approaches to quantum gravity. It has been argued that, if we look at the formalism from a strictly realistic perspective, it is possible to perform a metaphysical analysis of the physical theories which can eventually lead to physically relevant results. Some strong counter-arguments against strict realism have been also considered.
2. It has been performed a detailed and theory-independent analysis of the notions of general covariance, gauge invariance and symmetry, showing how these concepts apply in different theoretical contexts (mainly Newtonian mechanics and general relativity) and how they are deeply related to the notion of background independence. The analysis has been performed mainly from a metaphysical perspective, giving some philosophical arguments in favour of the adoption of general covariance and background independence as (meta)physical desiderata of an effective theory of spacetime.
3. It has been performed an extensive review of the philosophical debate regarding general relativity, mostly focused on the substantivalist vs. relationist dispute on the ontological status of spacetime (hole argument, issues on "Machianity" of general relativity, metaphysical problems in interpreting the metric tensor as a physical field). It has been argued that, for a strict realist, it is possible to avoid the moderate realist counter-arguments by adopting a metaphysical view known as "metric essentialism". By pushing forward this essentialistic ontology, it has been possible to argue in favour of a five-dimensional implementation of general relativity, known as Space-Time-Matter theory, showing that, in the context of this latter theory, many metaphysical flaws of general relativity can be mitigated or fixed.
4. A thorough investigation of the physical and philosophical literature on the Hamiltonian formulation of general relativity and its quantization - which constitutes the first step of the so called canonical approach to quantum gravity - has been carried out, with a particular focus on the notions of foliation of spacetime and gauge freedom. Both notions have, in fact, a huge metaphysical impact on the interpretations of Hamiltonian general relativity and canonical quantum gravity because, if taken at face value, these features seem to push us to accept time-independent physical quantities as the only meaningful observables both in the classical and in the quantum regime. We are then forced to draw a picture of reality where the dynamical evolution of any system and the very notion of time are deprived of physical meaning: all these metaphysical issues are usually grouped under a common designation, i.e. "the problem of time". The research has showed how in fact convincing arguments can be constructed against the timeless interpretation of Hamiltonian general relativity and canonical quantum gravity. The starting point for doing so has been noticing that, contrary to what commonly stated in the standard physical literature, giving a Hamiltonian formulation of general relativity does not presuppose as a vital requirement any foliation of spacetime and, hence, the 3+1 splitting of spacetime which constitutes a basic pre- requisite for setting up the problem of time, can be avoided.
5. The philosophical inquiry into the above issues has led to the development of an original philosophical position dubbed "weak essentialism", which is able to account for a metaphysics of objects lacking primitive identity suitable to meet the philosophical challenges posed by general covariance and, more generally, by gauge freedom in the context of spacetime theories.