Identical quantum particles and weak discernibility

2007

Journal for General Philosophy of Science, 2020

According to classical physics particles are basic building blocks of the world. These classical particles are distinguishable objects, individuated by unique combinations of physical properties. By contrast, in quantum mechanics the received view is that particles of the same kind (“identical particles”) are physically indistinguishable from each other and lack identity. This doctrine rests on the quantum mechanical (anti)symmetrization postulates together with the “factorist” assumption that each single particle is represented in exactly one factor space of the tensor product Hilbert space of a many-particle system. Even though standard in theoretical physics and the philosophy of physics, the assumption of factorism and the ensuing indistinguishability of particles are problematic. Particle indistinguishability is irreconcilable with the everyday meaning of “particle”, and also with how this term is used in the practice of physics. Moreover, it is a consequence of the standard vi...

Synthese, 1986

Philosophy of Science, 2009

We maximally extend the quantum-mechanical results of Muller and Saunders (2008) establishing the ‘weak discernibility’ of an arbitrary number of similar fermions in finite-dimensional Hilbert spaces. This confutes the currently dominant view that (A) the quantum-mechanical description of similar particles conflicts with Leibniz's Principle of the Identity of Indiscernibles (PII); and that (B) the only way to save PII is by adopting some heavy metaphysical notion such as Scotusian haecceitas or Adamsian primitive thisness. We take sides with Muller and Saunders (2008) against this currently dominant view, which has been expounded and defended by many.

2014

The paper discusses how to formally represent properties characterizing individual components of quantum systems containing many particles of the same type. It is argued that this can be done using only fully symmetric projection operators. An appropriate interpretation is proposed and scrutinized, and its consequences related to the notion of quantum entanglement and the issue of discernibility and individuality of quantum particles are ascertained.

Facta Philosophica, 2008

Foundations of Phyiscs, 2000

… British journal for the philosophy of …, 2008

Erkenntnis, 2012

The Major Additions in the Samaritan Pentateuch: Editorial Practices and Layers, 2024

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