The Symmetry Principle

Detlef Dürr, Stefan Teufel

Otávio Bueno

In this paper, I argue that symmetry principles in physics (in particular, in quantum mechanics) have a methodological character, rather than an ontological or an epistemological one. First, I provide a framework to address three related issues regarding the notion of symmetry: (i) how the notion can be characterized; (ii) one way of discussing the nature of symmetry principles, and (iii) a tentative account of some types of symmetry in physics. To illustrate how the framework functions, I then consider the case of the early formulation of quantum mechanics, examining the different roles played by symmetry in this context. Finally, I raise difficulties for ontological and purely epistemological interpretations of symmetry principles, and offer a methodological alternative.

Gerald Feinberg

José Luis Rolleri

Curiés principle expresses an invariant connectiobn between symmetry of causes and symmetry of effects in deterministic systems. Here a probabilistic version of such principle is proposed and proved for indeterministic systems. In contrast with Curie´s principle, our probabilistic version involves the invariance of the probabilities that laws assign to physically possible final states of random processes under symmetry transformations, although with exceptions when a phenomenon breaks the symmetry in question.

George H. Weinberg, Diane L. Rowe

Felix Tennie, Vlatko Vedral, Christian Schilling

Pauli's exclusion principle has a strong impact on the properties of most fermionic quantum systems. Remarkably, the fermionic exchange symmetry implies further constraints on the one-particle picture. By exploiting those generalized Pauli constraints, we derive a measure which quantifies the influence of the exchange symmetry beyond Pauli's exclusion principle. It is based on a geometric hierarchy induced by the exclusion principle constraints. We provide a proof of principle by applying our measure to a simple model. In that way, we conclusively confirm the physical relevance of the generalized Pauli constraints and show that the fermionic exchange symmetry can have an influence on the one-particle picture beyond Pauli's exclusion principle. Our findings provide a perspective on fermionic multipartite correlation since our measure allows one to distinguish between static and dynamic correlations.