Unless flavour symmetries are assumed, particle masses and mixings are generally undetermined in gauge theories. Understanding mass and mixing constitutes one of the biggest challenges in elementary particle physics. Current observations do not determine all elements of the effective neutrino mass matrix Mν completely and this will be a great challenge even for future experiments. Therefore the...

Newtonian mechanics posited mass as a primary quality of matter, incapable of further elucidation. We now see Newtonian mass as an emergent property. That mass-concept is tremendously useful in the approximate description of baryon-dominated matter at low energy – that is, the standard “matter” of everyday life, and of most of science and engineering – but it originates in a highly contingent a...

We derive compact analytical formulae of the Bonneau-Martin type for the reaction e + e − → ¯ f f γ with cuts on minimal energy and acollinearity of the fermions, where the photons may be emitted both from the initial or final states. Soft-photon exponentiation is also taken into account. One of the cleanest scattering processes at elementary particle accelerators is fermion-pair production in ...

We derive compact analytical formulae of the Bonneau-Martin type for the reaction e + e − → ¯ f f γ with cuts on minimal energy and acollinearity of the fermions, where the photons may be emitted both from the initial or final states. Soft-photon exponentiation is also taken into account. One of the cleanest scattering processes at elementary particle accelerators is fermion-pair production in ...

In standard Poincare and anti de Sitter SO(2,3) invariant theories, the existence of antiparticles is explained by using the fact that covariant equations have solutions with negative energies. In these theories a particle and its antiparticle are described by independent positive energy irreducible representations (IRs) of the symmetry group. Such an approach cannot be applied in de Sitter SO(...

We consider the interaction of gravity, as expressed by Einstein’s Equations of General Relativity, to other force fields. We describe some recent results, discussing both the mathematics, and the physical interpretations. These results concern both elementary particles, as well as cosmological models. (This paper describes joint work variously done with with F. Finster, N. Kamran, B. Temple, a...

These proceedings summarize lectures that were delivered as part of the 2002 and 2003 Theoretical Advanced Study Institutes in elementary particle physics (TASI) at the University of Colorado at Boulder. They are intended to provide a pedagogical introduction to cosmology aimed at advanced graduate students in particle physics and string theory.

These proceedings summarize lectures that were delivered as part of the 2002 and 2003 Theoretical Advanced Study Institutes in elementary particle physics (TASI) at the University of Colorado at Boulder. They are intended to provide a pedagogical introduction to cosmology aimed at advanced graduate students in particle physics and string theory.

The QCD sector of the system SANC is presented. QCD theoretical predictions for several processes of high energy interactions of fundamental particles at the one-loop precision level for up to some 3and 4-particle processes are implemented.

In theoretical physics, paradoxes are good. That’s paradoxical, since a paradox appears to be a contradiction, and contradictions imply serious error. But Nature cannot realize contradictions. When our physical theories lead to paradox we must find a way out. Paradoxes focus our attention, and we think harder. When David Gross and I began the work that led to this Nobel Prize [1, 2, 3, 4], in 1...