Related papers: Copositive criteria for a two-component dark matte…
We study two types of models involving a scalar dark matter multiplet of global $O(N)$ symmetry. These models are distinguished by the absence (Type I) or presence (Type II) of a scalar mediator with $Z_{2}$ symmetry. We derive the allowed…
Dark matter (comprising a quarter of the Universe) is usually assumed to be due to one and only one weakly interacting particle which is neutral and absolutely stable. We consider the possibility that there are several coexisting…
Perturbative gauge coupling unification in realistic superstring models suggests the existence of additional heavy down-type quarks, beyond the minimal supersymmetric standard model. The mass scale of the heavy down-type quarks is…
We discuss radiative seesaw models, in which an exact $Z_2\times Z_2'$ symmetry is imposed. Due to the exact $Z_2\times Z_2'$ symmetry, neutrino masses are generated at a two-loop level and at least two extra stable electrically neutral…
We propose a two component dark matter set-up by extending the Standard Model with a singlet and a hypercharge-less triplet scalars, each of them being odd under different $Z_2$ symmetries. We observe that the inter-conversion between the…
We consider the minimal scalar singlet dark matter stabilised by a $Z_3$ symmetry. Due to the cubic term in the scalar potential, semi-annihilations, besides annihilations, contribute to the dark matter relic density. Unlike in the $Z_2$…
We consider a model in which dark matter is stable as it is charged under a Z2 symmetry that is residual after an A4 flavour symmetry is broken. We consider the possibility to generate the quark masses by charging the quarks appropriately…
We investigate, for the first time, a scenario where the dark matter consists of three complex scalar fields that are stabilized by a single $Z_7$ symmetry. As an extension of the well-known scalar Higgs-portal, this $Z_7$ model is also…
A complete assessment of any dark matter model requires confronting its low-energy phenomenology with its high-scale theoretical viability. We undertake such a dual analysis for a class of two-component scalar dark matter models stabilized…
When CMB data are used to derive cosmological parameters, their very choice does matter: some parameter values can be biased if the parameter space does not cover the "true" model. This is a problem, because of the difficulty to parametrize…
We use observational data on the large scale structure (LSS) of the Universe measured over a wide range of scales from sub-galactic up to horizon scale and on the cosmic microwave background anisotropies to determine cosmological parameters…
We investigate the constraints and phenomenology of a three Higgs doublet model (3HDM) with a $\Z2\times\Z2$ symmetry, featuring two inert scalar doublets that give rise to a two-component dark matter (DM) scenario. We analyze the model's…
We present a new model for two-component scalar dark matter (DM), consisting of two complex scalar fields. In this model, both the DM components are stable due to the remaining $Z_4$ gauge symmetry, which is the remnant of the $U(1)^\prime$…
In many models, stability of dark matter particles is protected by a conserved Z_2 quantum number. However dark matter can be stabilized by other discrete symmetry groups, and examples of such models with custom-tailored field content have…
We study the cosmology of bimetric theory with a composite matter coupling. We find two possible branches of background evolution. We investigate the question of stability of cosmological perturbations. For the tensor and vector…
We consider a two-component dark matter model with $Z_2 \times Z_4$ symmetry, where a singlet scalar $S$ and a Majorana fermion $\chi$ are introduced as dark matter candidates. We also introduce another singlet scalar $S_0$ with a non-zero…
We update the constraints on the minimal model of dark matter, where a stable real scalar field is added to the standard model Lagrangian with a renormalizable coupling to the Higgs field. Once we fix the dark matter abundance, there are…
Models with an extended scalar electroweak sector can have vanishing vacuum expectation values in a basis where an underlying symmetry is imposed. Such extensions are very well motivated. If a symmetry prevents couplings between fermions…
We compute the constraints on a ``standard'' 10 parameter cold dark matter (CDM) model from the most recent CMB and data and other observations, exploring 30 million discrete models and two continuous parameters. Our parameters are the…
We study the experimental constraints on a model of a two-component dark matter, consisting of the QCD axion, and a scalar particle, both contributing to the dark matter relic abundance of the Universe. The global Peccei-Quinn symmetry of…