This morning we had a lecture by Elisabette Pallante on particle physics phenomenology. It was great to see what the current open problems are, and the challenges to understand: naturalness, hierarchy, Higgs vacuum stability and meta-stability bounds. A lively discussion followed, getting us back late for the seminars of Fedele Lizzi and Christoph Stephan. This was further delayed by a fight with the beamer, thanks to Apple 🙂

In any case, Lizzi showed us the possibility to generate the σ-field from a so-called Grand algebra, which contained an intriguing mixing of spinorial degrees of freedom with the finite noncommutative space. As opposed to dropping the first-order condition as described here, their approach (detailed here) demands however dropping the bounded-commutator condition. Next, Stephan showed us an alternative road to noncommutative model-building, proposing a model that contains in addition to the Standard Model a scalar field (of much lower mass) and additional fermions.

Again, the discussion in the afternoon study groups were very inspiring, ranging from a Lorentzian distance formula in the one group to the cosmological relevance of the σ-field in the other, and much more. Tomorrow, there will be a final plenary discussion to see where we stand after a week of lively NCG and PP interaction.