Motivated by the direct discovery of gravitational waves (GWs) from black holes and neutron stars, there is a growing interest in investigating GWs from other sources. Among them, GWs from cosmic strings are particularly fascinating since they naturally appear in a large class of grand unified theories (GUTs). Remarkably, a series of pulsar-timing arrays (PTAs) might have already observed GWs...
We present the latest progress in analyzing the minimal potentially realistic non-supersymmetric $\mathrm{SO}(10)$ GUT model, whose scalar sector consists of representations $45+126+10$. Although the model is expected to give a robust proton decay prediction, any analysis is hampered by tachyonic instabilities present in the tree-level scalar potential. The one-loop corrected effective...
I will briefly discuss two ideas in dark matter model building. They first is that axion dark matter may be connected with neutrino mass generation, baryogenesis and flavour-dependent Higgs Yukawa couplings. The second arises within a continuing search for a good theory of the dark matter mass scale in the asymmetric dark matter paradigm. In particular, I will present some recent results on...
In this talk, we consider the phenomenology of electrically neutral complex vector particles V with a mass below the GeV-scale, but with higher dimensional form factor interactions to the SM photon. The astrophysics, cosmology and direct detection phenomenology will be presented.
We strengthen the cosmological bound on the axion mass, by solving the momentum-dependent Boltzmann equations for axion-pion scatterings and by using a phenomenological production rate derived from pion-pion scattering data, overcoming the breakdown of chiral perturbation theory. Using present cosmological datasets we obtain m_a < 0.24 eV. To further improve the bound and exploit the reach of...
We discuss examples of three Higgs doublet models which can provide good dark matter candidates. The emphasis is on models with S_3 symmetry, with or without spontaneous CP violation. Some aspects of the Weinberg potential will also be discussed.
I discuss the impact of triple-leptoquark interactions on matter stability for two specific proton decay topologies that arise at the tree- and one-loop level if and when they coexist. I furthermore demonstrate that the one-loop level topology is, in such an instance, much more relevant than the tree-level one despite the usual loop-suppression factor. To support that claim I present detailed...
A non-minimal dark sector could explain why WIMP dark matter has evaded detection so far. Based on the extensively studied example of a simplified t-channel dark matter model involving a colored mediator, we demonstrate that the Sommerfeld effect and bound state formation must be considered for an accurate prediction of the relic density and thus also when inferring the experimental...
We critically analyse the future of composite dynamics via the impact of non standard model Higgs on the (non) observed g-2 and W-mass anomalies.
The ultimate dream of unification models consists in combining both gauge and Yukawa couplings into one unified coupling. This is achieved by using a supersymmetric exceptional ${\rm E}_6$ gauge symmetry together with asymptotic unification in compact five-dimensional space-time. The ultraviolet fixed point requires exactly three fermion generations: one in the bulk, and the two light ones...
Subtle, but long-known, field-theoretical aspects require a more refined treatment of gauge theories involving a Brout-Englert-Higgs effect. This refinement can be analytically done using the Fröhlich-Morchio-Strocchi mechanism. In the standard model, this leads to slight, but in principle detectable, quantitative changes in observables. For many theories beyond the standard model, the effects...
I will discuss how dark matter long range interactions with itself or with the baryons leave unique signatures in precision cosmological observables. I will present exquisitely sensitive probes of these interactions in galactic surveys and in 21cm cosmology and discuss the challenges of the theory predictions.
