Quantum Chromodynamics (QCD) exhibits dynamical chiral symmetry breaking and confinement. Both features are related with global symmetries of the QCD Lagrangian. While the chiral symmetry is exact in the limit of massless quarks the Z(3) center symmetry, which governs confinement, is exact in the opposite limit, i.e., for infinitely heavy quarks. The susceptibilities of the corresponding order ...

We give a version of Noether theorem adapted to the framework of μ-symmetries; this extends to such case recent work by Muriel, Romero and Olver in the framework of λ-symmetries, and connects μ-symmetries of a Lagrangian to a suitably modified conservation law. In some cases this “μconservation law” actually reduces to a standard one; we also note a relation between μ-symmetries and conditional...

We discuss some of the topological features of a non-interacting two (1 + 1)-dimensional Abelian gauge theory in the framework of superfield formulation. This theory is described by a BRST invariant Lagrangian density in the Feynman gauge. We express the local and continuous symmetries, Lagrangian density, topological invariants and symmetric energy momentum tensor of the theory in the language...

Lagrangian symmetries and concomitant generalized Bianchi identities associated with the relabeling of fluid elements are found for hydrodynamics and magnetohydrodynamics (MHD). In hydrodynamics, relabeling results in Ertel's theorem of conservation of potential vorticity, while in MHD it yields the conservation of cross helicity. The symmetries of the reduction from Lagrangian (material) to Eu...