%0 Journal Article 
%A Aldaya Valverde, Víctor
%A Calixto Molina, Manuel
%T Central extensions and quantum physics
%D 2008
%U http://hdl.handle.net/10317/528
%U arXiv:hep-th/9903141v2
%X The unitary implementation of a symmetry group G of a classical system in the
corresponding quantum theory entails unavoidable deformations ˜G of G, namely,
central extensions by the typical phase invariance group U(1). The appearance
of central charges in the corresponding Lie-algebra quantum commutators, as
a consequence of non-trivial responses of the phase of the wave function under
symmetry transformations, lead to a quantum generation of extra degrees of
freedom with regard to the classical counterpart. In particular, symmetries of
the Hall effect, Yang-Mills and conformally invariant classical field theories are
affected when passing to the quantum realm.
%K Matemática Aplicada
%K Teoría de campos cuánticos
%K Teorías Yang-Mills
%K Teoría cuántica
%K Simetría de grupo G
%~ GOEDOC, SUB GOETTINGEN