Title: A minimal SM/LCDM cosmology

Abstract:
Recent observations point to a surprisingly economical description of the universe on both very small and very large scales. Stimulated by these findings, Boyle and I have proposed a new, potentially more complete theoretical framework than currently popular paradigms. Our search has so far led to 1) the simplest-yet explanation for the cosmic dark matter, soon to be tested by galaxy surveys, 2) a thermodynamic explanation for the large scale geometry of the cosmos, not requiring inflation, based on a new calculation of the gravitational entropy for cosmological spacetimes, 3) a new account of the big bang singularity as a “mirror” enforcing CPT symmetry, linked to analyticity and asymptotic Weyl symmetry at the bang, 4) a new mechanism involving dimension zero scalar fields for cancelling the divergent vacuum energy and the trace anomalies in the Standard Model (SM) without introducing any new particles. This mechanism explains why there are 3 generations of elementary particles, each with a RH neutrino. One of them is stable and comprises the dark matter. Remarkably, the same mechanism predicts primordial density perturbations, parameterised in terms of SM gauge couplings, which are in quantitative agreement with the observations. I’ll report on recent calculations providing evidence that dimension zero fields form a unitary 4d quantum field theory of a new type, exhibiting asymptotic freedom and Weyl symmetry but where the only physical state is the vacuum. They seem to be just what we need to couple the standard model to gravity consistently.

Speaker: Neil Turok - Higgs Centre for Theoretical Physics, The University of Edinburgh, UK

Date and Time: April 3rd, 2024 - 12pm GMT