U_A(1) Anomaly at high temperature: the scalar-pseudoscalar splitting in QCD
U_A(1) Anomaly in Hot and Dense QCD and the Critical Surface
U_A(1) Breaking Effects on the Light Scalar Meson Spectrum
U_A(1) Problems and Gluon Topology - Anomalous Symmetry in QCD
U_A(1) Symmetry Breaking and eta, eta prime mesons in the Bethe-Salpeter Approach
U_A(1) symmetry breaking, scalar mesons and the nucleon spin problem in an effective chiral field theory
U_e(1)--covariant R_ξ--gauge for the two Higgs doublet model
U_e(1)xU_g(1) Actions in 2+1-Dimensions: Full Vectorial Electric and Magnetic Fields
U_q(N) Gauge Theories
U_{PMNS} = U_ell^dagger U_nu