In a fermionic quantum vacuum, the parameters kÎ¼ of a CPT-violating Chernâ€“Simons-like action term induced by CPT-violating parameters bÎ¼ of the fermionic sector depend on the universality class ofâ€¦ (More)

The merging of the running couplings constants of the weak, strong, and electromagnetic fields does not require the unification of these gauge fields at high energy. It can, in fact, be the propertyâ€¦ (More)

We present a self-consistent ansatz for a new sphaleron in the electroweak standard model. The resulting field equations are solved numerically. This sphaleron sets the height of the energy barrierâ€¦ (More)

We consider chiral gauge theories defined over a fixed four-dimensional space-time manifold with a Cartesian product structure for at least one compact spatial dimension, e.g. the product ofâ€¦ (More)

We present a three-parameter neutrino-oscillation model for three flavors of massless neutrinos with Fermi-point splitting and tri-maximal mixing angles. One of these parameters is the Tâ€“violatingâ€¦ (More)

We consider the process of photon decay in quantum electrodynamics with a CPTviolating Chernâ€“Simons-like term added to the action. For a simplified model with only the quadratic Maxwell andâ€¦ (More)

Our Universe is perhaps a domain separated by physical phase boundaries from other domain-Universes with different vacuum energy density (cosmological constant) and matter content. The coexistence ofâ€¦ (More)

Institut fÃ¼r Theoretische Physik, UniversitÃ¤t Karlsruhe (TH), 76128 Karlsruhe, Germany Abstract The CPT anomaly of certain chiral gauge theories has been established previously for flat multiplyâ€¦ (More)

Our goal is to discover possible new 4-dimensional euclidean solutions (instantons) in fundamental SU(2) Yang-Mills-Higgs theory, with a constraint added to prevent collapse of the scale. We showâ€¦ (More)

We discuss the quantum phase transition which separates a vacuum state with fully-gapped fermion spectrum from a vacuum state with topologically-protected Fermi points (gap nodes). In the context ofâ€¦ (More)