In this talk, I will present the anatomy of production mechanisms for sterile neutrino dark matter, a keV-scale gauge-singlet fermion that mixes with active neutrinos, in the presence of new interactions among active neutrinos. These new interactions allow sterile neutrinos to make up all the DM while safely evading all current experimental bounds. The existence of these new neutrino...
Dirac neutrinos with Dark photon portal for Dark matter
In this talk we present the phenomenology of the Z5 model for two-component dark matter. This model, which can be seen as an extension of the well-known singlet scalar model, features two complex scalar fields--the dark matter particles--that are Standard Model singlets but have different charges under a Z5 symmetry. The interactions allowed by the Z5 give rise to novel processes between the...
Due to their extreme density and low temperature, compact objects such as old neutron stars (NS) are efficient probes to unveil interactions between standard model and dark matter (DM) particles. From elastic scatterings on NS matter, DM can get gravitationally trapped by the star. The in-falling DM unavoidably transfers heat to the NS and can heat up old NS up to 1700 K. Moreover, if DM is...
Ordinary matter is in the form of bound states. The simple example is hydrogen, which is a bound state of one proton and one electron. Another example is the proton itself, which is a bound state of the elementary particles of QCD. In the light of this, it is natural to ask whether dark matter is made of bound states or if it is an elementary particle that can form them.
This talk is devoted...
In this talk we introduce the neutrino mass problem of the Standard Model of particle physics. Then, we analyze how to generate these masses by introducing right-handed Majorana singlets in the type 1 Seesaw mechanism framework. Afterwards, we explain the origin of these masses through the spontaneous symmetry breaking of a global U(1) symmetry, which introduces a new scalar singlet with a...
A Peccei-Quinn~(PQ) symmetry is proposed, in order to generate in the Standard Model~(SM) quark sector a realistic mass matrix ansatz with five texture-zeros. Limiting our analysis to Hermitian mass matrices we show that this requires a minimum of 4 Higgs doublets. This model allows assigning values close to 1 for several Yukawa couplings, giving insight into the origin of the mass scales in...
We propose an extension of the Standard Model (SM) based on the SU(3)C⊗SU(3)L⊗U(1)X (3-3-1) gauge symmetry and scale invariance. Maintaining the main features of the so-called 3-3-1 models, such as the cancellation of gauge anomalies related to the number of chiral fermion generations, this model exhibits a very compact scalar sector. Only two scalar triplets and one singlet are necessary and...
Axions have for some time been considered a plausible candidate for dark matter. They can be produced through misalignment, but it has been argued that when inflation occurs before a Peccei-Quinn transition, appreciable production can result from cosmic strings. This has been the subject of extensive simulations. But there are reasons to be skeptical about the possible role of axion strings....
We consider an UV-protected Natural Inflation scenario involving Chern-Simons-like interactions between the inflaton and some beyond the Standard Model gauge fields. The accelerated expansion of the Universe is supported by a combination of a gravitationally-enhanced friction sensitive to the scale of inflation and quantum friction effects associated with the explosive production of gauge...
If the interaction rates between the visible and the dark sectors were never strong enough, the observed dark matter relic abundance could have been produced in the early Universe by non-thermal processes. This is what occurs in the so-called freeze-in mechanism. In the simplest version of the freeze-in paradigm, after dark matter is produced from the standard model thermal bath, its abundance...
Devices with low energy thresholds are one of the main pillars for the direct detection of dark matter, and tremendous progress has been made in the past few years in probing dark matter with sub-GeV masses. The SENSEI (Sub-Electron Noise Skipper Experimental Instrument) Collaboration has pioneered the silicon-based Skipper-Charge Coupled Device (CCD) technology capable of detecting electron...
In this talk, we will review some phenomenological diffusion models within the gravitational framework of Unimodular Gravity. We will show that, when regarding non-gravitational interactions between cold dark matter and an effective cosmological constant, it is possible to address one of the modern cosmological problems: the discrepancy between the early and late time inferred value of the...
Substructures formed during the accretion of mass in the process of structure and galaxy formation can be used as a test to study the presence and nature of dark matter.
In this particular talk we study the formation of polar ring galaxies via minor mergers of galaxies. We used N-body + hydrodynamics simulations to reproduce the dynamics of the observed system AM 2229-735 that is a minor...
The identity of Dark Matter (DM) is one of the most active topics in particle physics today. Supersymmetric models, theoretical extensions of the Standard Model (SM), provide possible explanations to the particle nature of DM. Considering R-parity conservation in supersymmetric models such as the Minimal Supersymmetric Standard Model (MSSM) provides a natural DM candidate: the lightest...
