We discuss the constraints and phenomenology of the Z2×Z2 three Higgs
doublet model (3HDM) with two inert scalars, originating two dark matter
(DM) particles. We elucidate the competing vacua and we submit the model
to all theoretical, collider and astrophysical constraints. We find
unexplored regions of parameter space and investigate their experimental
signatures. The whole mass range...
Dark Hydrogen Atoms as Baryonic Dark Matter
From the most detailed map of the cosmic microwave background at the end of the recombination
epoch, the Plank Collaboration deduced the existence of the baryonic dark matter (DM) in the ratio
1:5 to the non-baryonic DM. So, the baryonic DM does exist. The explanation of a puzzling
observation by Bowman et al (2018) of the redshifted 21 cm...
The Lorentz gauge theory of gravity with a spontaneous symmetry breaking field,
sometimes dubbed ”khronon”, provides a successful description of the ΛCDM model in
which the dark matter candidate arises as a geometric effect. A chiral formulation of this
theory has been found to be an extension of General Relativity, and this theory is being
studied in phenomenological contexts of black...
The properties of dark matter affect its distribution in the universe. In particular, the mass of dark matter defines a characteristic free streaming length under which structure formation is suppressed. While this length is negligible for standard cold dark matter, it can be of the order of galactic sizes for warm dark matter with mass ~ 1keV, and thus have observational effects. Current...
In this project we will analyse a theory with non-minimal matter–curvature coupling,
considering non–metricity properties with a Weyl connection. This model has the
advantage of an extra force term which can mimic dark matter and dark energy, and
simultaneously follow Weyl’s idea of unifying gravity and electromagnetism. Indeed,
we can show astrophysical results like Schwarzschild and...
I will report on some recent results on simple extensions of the Standard Model with scalar Dark matter candidates.
— We present a new perturbative method to find the solutions of systems of equations in the neighbourhood
of known solutions. Given a known solution to a system of equations, the proposed method allows one to find both the
dimension of the solution space around it and to construct a power series for the set of solutions in its neighbourhood –
and it does provide as many such answers as...
The SM for particle physics is surprisingly successful. It is based on symmetry principles of various types. I will first recapitulate basic assumptions and key aspects of the SM, emphasizing differences between global vs. local gauge symmetries. Then I will apply similar assumptions and aspects to the DM model buildings.
I will discuss a few exemplary DM models and demonstrate...
We shall review the cosmic generalisation of the virial theorem, known as the Layzer-Irvine equation, also independently derived by Dmitriev and Zeldovich. This equation has been studied in the literature for both dark matter and dark matter-dark energy interaction models, as well as in the context of alternative theories of gravity. We shall discuss some results of the previous scenarios and...
We present the C++ program RelExt for Standard Model (SM) extensions that feature a Dark Matter (DM) candidate. The tool allows to efficiently scan the parameter spaces of these models to find parameter combinations that lead to relic density values which are compatible with the measured value within the uncertainty specified by the user. The code computes the relic density for freeze-out...
Precanonical quantum gravity posits a quantum geometry of spacetime characterized by a fluctuating spin connection foam (SCF). This framework naturally yields a characteristic acceleration scale, $a_*=8\pi G \hbar \varkappa$, which is related to the cosmological constant, $\Lambda \sim (8\pi G \hbar \varkappa)^2$ Here, $\varkappa \sim (\Delta m)^3$ represents a parameter inherent to the...
Recently, a Modified Gravity Theory named Einstein-scalar-Gauss-Bonnet (EsGB) gravity, a string-inspired theory that admits a coupling between an extra scalar field and the Gauss-Bonnet invariant, has been gaining some attention due to its rich phenomenology. Motivated by its theoretical advancements, we explored the cosmology of the theory in a model-independent manner by using the dynamical...
Strongly interacting massive particles π have been advocated as prominent dark matter candidates when they regulate their relic abundance through odd-numbered 3π→2π annihilation. We show that successful freeze-out may also be achieved through even-numbered interactions XX→ππ once bound states X among the particles of the low-energy spectrum exist. In addition, X-formation hosts the potential...
We extend the black hole holography to the case of an asymptotically anti-de Sitter (AdS) rotating charged black holes in f (T) = T + αT2 gravity, where α is a constant. We find that the scalar wave radial equation at the near-horizon region implies the existence of the 2D conformal symmetries. We show that choosing proper central charges for the dual CFT, we produce exactly the macroscopic...
When building dark matter (DM) models, one often imposes conserved discrete symmetries to stabilize DM candidates. The simplest choice is Z2 but models with larger stabilizing groups have also been explored. Can a conserved non-abelian group lead to a viable DM model? Here, we address this question within the three-Higgs-doublet model based on the group Σ(36), in which DM stabilization by a...
Many dark matter models become unviable when embedded into the framework of asymptotically safe quantum gravity. In this work, we investigate dark matter arising as bound states of fundamental fermions in the strongly-coupled regime of a gauge theory. Modeling the self-interactions of dark baryons via the effective-range approach, we perform a multi-scale analysis in which we combine...
