We explore the self-interacting dark matter scenario in a simple dark sector model where the dark matter interacts through a dark photon. Splitting a Dirac fermion dark matter into two levels using a small Majorana mass can evade strong direct detection constraints on the kinetic mixing between the dark and normal photons, thus allowing the dark sector to be more visible at high intensity and/or high energy experiments. It is pointed out that such a mass splitting has a strong impact on the dark matter self-interaction strength. We derive the new parameter space of a pseudo-Dirac self-interacting dark matter. Interestingly, with increasing mass splitting, a weak scale dark matter mass window survives that could be probed by the LHC and future colliders.
Self-interacting dark matter resolves the issue of cuspy profiles that appear in non-interacting cold dark matter simluations; it may additionally resolve the so-called "too big to fail" problem in structure formation. Asymmetric dark matter provides a natural explanation of the comparable densities of baryonic matter and dark matter. In this paper, we discuss unique indirect detection signals produced by a minimal model of self-interacting asymmetric scalar dark matter. Through the formation of dark matter bound states, a dark force mediator particle may be emitted; the decay of this particle…
We present models of resonant self-interacting dark matter in a dark sector with QCD, based on analogies to the meson spectra in Standard Model QCD. For dark mesons made of two light quarks, we present a simple model that realizes resonant self-interaction (analogous to the $ϕ$-K-K system) and thermal freeze-out. We also consider asymmetric dark matter composed of heavy and light dark quarks to realize a resonant self-interaction (analogous to the $Υ(4S)$-B-B system) and discuss the experimental probes of both setups. Finally, we comment on the possible resonant self-interactions already built…
We present an effective non-relativistic theory of self-interacting dark matter. We classify the long range interactions and discuss how they can be generated from quantum field theories. Generic dark sectors can generate singular potentials. We show how to consistently renormalize such potentials and apply this to the calculation of the Sommerfeld enhancement of dark matter interactions. We explore further applications of this enhancement to astrophysical probes of dark matter including the core vs. cusp problem.
The hypothesis of dark matter interacting with the standard model uniquely via the Higgs portal is severely challenged by experiments. However, if dark matter is a fermion, the Higgs-portal interaction implies the presence of mediators, which can change the phenomenology significantly. This article discusses the impact of weakly-interacting mediators on the dark-matter relic abundance, direct detection, and collider searches. At the LHC, a typical signature of Higgs-portal fermion dark matter features soft leptons and missing energy, similarly to gaugino production in models with supersymmetry…
We study the possibility that self-interacting bosonic dark matter forms star-like objects. We study both the case of attractive and repulsive self-interactions, and we focus particularly in the parameter phase space where self-interactions can solve well standing problems of the collisionless dark matter paradigm. We find the mass radius relations for these dark matter bosonic stars, their density profile as well as the maximum mass they can support.
A new understanding of the stability of self-interacting dark matter is pointed out, based on the simplest spontaneously broken Abelian $U(1)$ gauge model with one complex scalar and one Dirac fermion. The key is the imposition of dark charge conjugation symmetry. It allows the possible existence of two stable particles: the Dirac fermion and the vector gauge boson which acts as a light mediator for the former's self-interaction. Since this light mediator does not decay, it avoids the strong cosmological constraints recently obtained for all such models where the light mediator decays into sta…
We investigate a mechanism for the production of self-interacting dark matter based on WIMP-like messenger state decays into dark matter and dark radiation occurring after recombination. Such a transition leads to a mild relaxation of the Hubble tension, and at the same time may resolve the small-scale structure problems of the $Λ$CDM. We illustrate this mechanism in the Higgs portal dark matter model, which we find to be a promising route.
An extra dark radiation component can be present in the universe in the form of sterile neutrinos, axions or other very light degrees of freedom which may interact with the dark matter sector. We derive here the cosmological constraints on the dark radiation abundance, on its effective velocity and on its viscosity parameter from current data in dark radiation-dark matter coupled models. The cosmological bounds on the number of extra dark radiation species do not change significantly when considering interacting schemes. We also find that the constraints on the dark radiation effective velocit…
We consider thermal production mechanisms of self-interacting dark matter in models with gauged $Z_3$ symmetry. A complex scalar dark matter is stabilized by the $Z_3$, that is the remnant of a local dark $U(1)_d$. Light dark matter with large self-interaction can be produced from thermal freeze-out in the presence of SM-annihilation, SIMP and/or forbidden channels. We show that dark photon and/or dark Higgs should be relatively light for unitarity and then assist the thermal freeze-out. We identify the constraints on the parameter space of dark matter self-interaction and mass in cases that o…
In this work, we discuss the relation between the strength of the self-interaction of dark matter particles and the predicted properties of the inner density distributions of dark matter haloes. We present the results of $N$-body simulations for 28 haloes performed with the same initial conditions for cold dark matter and for self-interacting dark matter, for a range of cross-sections. We provide a simple phenomenological description of these results and compare with the semi-analytical model typically used in the literature. Using these results, we then predict how the inner dark matter surfa…
We show that models of strongly interacting (SIMP) dark matter built to reproduce the DAMA signal actually cannot account for its time dependence. We discuss the constraints on this type of models coming from direct detection experiments and study the propagation of thermalised dark matter particles in the ground for the allowed values of the parameters. We consider a simple 1D diffusion and a more detailed 3D diffusion. In both cases the predicted signal has either the wrong phase of the annual modulation or a much larger amplitude of the diurnal modulation.
Dark matter self-interactions have important implications for the distributions of dark matter in the Universe, from dwarf galaxies to galaxy clusters. We present benchmark models that illustrate characteristic features of dark matter that is self-interacting through a new light mediator. These models have self-interactions large enough to change dark matter densities in the centers of galaxies in accord with observations, while remaining compatible with large-scale structure data and all astrophysical observations such as halo shapes and the Bullet Cluster. These observations favor a mediator…
We study the correlation between a monochromatic signal from annihilating dark matter and its self-interacting cross section. We apply our argument to a complex scalar dark sector, where the pseudo-scalar plays the role of a warm dark matter candidate while the scalar mediates its interaction with the Standard Model. We combine the recent observation of the cluster Abell 3827 for self-interacting dark matter and the constraints on the annihilation cross section for monochromatic X-ray lines. We also confront our model to a set of recent experimental analyses and find that such an extension can…
Self-interacting dark matter has been proposed as a solution to small scale problems in cosmological structure formation, and hints of dark matter self scattering have been observed in mergers of galaxy clusters. One of the simplest models for self-interacting dark matter is a particle that is charged under dark electromagnetism, a new gauge interaction analogous to the usual electromagnetic force, but operating on the dark matter particle instead of the visible particles. In this case, the collisional behaviour of dark matter is primarily due to the formation of collisionless shocks, that sho…
We study the interacting dark energy model with time varying dark energy equation of state. We examine the stability in the perturbation formalism and the degeneracy among the coupling between dark sectors, the time-dependent dark energy equation of state and dark matter abundance in the cosmic microwave background radiation. Further we discuss the possible ways to break such degeneracy by doing global fitting using the latest observational data and we get a tight constraint on the interaction between dark sectors.
We review the current status of model building for light dark matter in theories of QCD-like gauge groups in the hidden sector. The focus is upon the dark mesons with the $SU(3)_V$ flavor symmetry in scenarios of Strongly Interacting Massive Particles. We show the production mechanism and the kinetic equilibrium condition for dark mesons and discuss a unitarization of dark chiral perturbation theory with vector mesons in the scheme of hidden gauge symmetry.
We present a model of partially interacting dark matter (PIDM) within the framework of supersymmetry with gauge mediated symmetry breaking. Dark sector atoms are produced through Affleck-Dine baryogenesis in the dark sector while avoiding the production of Q-ball relics. We discuss the astrophysical constraints relevant for this model and the possibility of dark galactic disk formation. In addition, jet emission from rotating black holes is discussed in the context of this class of models.
We consider an interacting field theory model that describes the dark energy - dark matter interaction. Only for a specific interaction term, this interacting field theory description has an equivalent interacting fluid description. For inverse power law potentials and linear interaction function, we show that the interacting dark sector model with field-fluid mapping is consistent with \textit{four cosmological data sets} -- Hubble parameter measurements (Hz), Baryonic Acoustic Oscillation data (BAO), Supernova Type Ia data (SN), and High redshift HII galaxy measurements (HIIG). More specific…
In this paper, we investigate the observational constraints on the scenario of vacuum energy interacting with cold dark matter. We consider eight typical interaction forms in such an interacting vacuum energy scenario. The observational data used in this work to constrain these models include the JLA sample of type Ia supernovae observation, the Planck 2015 distance priors data of cosmic microwave background anisotropies observation, the baryon acoustic oscillations data, and the Hubble constant direct measurement. We find that the current observational data almost equally favor these interact…
A cosmological model of dark energy interacting with dark matter and another general component of the universe is investigated. We found general constraints on these models imposing an accelerated expansion. The same is also studied in the case for holographic dark energy.
There is no unique way to describe the dark energy-dark matter interaction, as we have little information about the nature and dynamics of the dark sector. Hence, in many of the phenomenological dark matter fluid interaction models in the literature, the interaction strength $Q_ν$ in the dark sector is introduced by hand. Demanding that the interaction strength $Q_ν$ in the dark sector must have a field theory description, we obtain a unique form of interaction strength. We show the equivalence between the fields and fluids for the $f(R,χ)$ model where $f$ is an arbitrary, smooth function of $…
We discuss how to formulate a quantum field theory of dark energy interacting with dark matter. We show that the proposals based on the assumption that dark matter is made up of heavy particles with masses which are very sensitive to the value of dark energy are strongly constrained. Quintessence-generated long range forces and radiative stability of the quintessence potential require that such dark matter and dark energy are completely decoupled. However, if dark energy and a fraction of dark matter are very light axions, they can have significant mixings which are radiatively stable and perf…
The short distance behavior of dark matter (DM) at galaxy scales exhibits several features not explained by the typical cold dark matter (CDM) with velocity-independent cross-section. We discuss a particle physics model with a hidden sector interacting feebly with the visible sector where a dark fermion self-interacts via a dark force with a light dark photon as the mediator. We study coupled Boltzmann equations involving two temperatures, one for each sector. We fit the velocity-dependent DM cross-section to the data from scales of dwarf galaxies to clusters consistent with relic density cons…
We investigate the possibility that dark matter could be made from CP-even and CP- odd Higgs bosons in the SU(3)_C X SU(3)_L X U(1)_N (3-3-1) model with right-handed neutrinos. This self-interacting dark matters are stable without imposing of new symmetry and should be weak-interacting.
In models where dark matter and dark energy interact non-minimally, the total amount of matter in a fixed comoving volume may vary from the time of recombination to the present time due to energy transfer between the two components. This implies that, in interacting dark energy models, the fractional matter density estimated using the cosmic microwave background assuming no interaction between dark matter and dark energy will in general be shifted with respect to its true value. This may result in an incorrect determination of the equation of state of dark energy if the interaction between dar…
We consider a model in which dark matter consists of a large self-interacting component (SIDM particles) and a small component with strong interactions with baryons (SIMPs). We show that the DAMA annual modulation signal can be caused by SIDM particles interacting with SIMPs trapped in iodine nuclei in the DAMA/NaI detector.
Massive states (of order 10 Gev and more) of hadron string (with scale 1 Gev) can have very small coupling constants with usual baryons of the Universe. Corresponding mean times for them are found to be order and even more than the age of the Universe. They are proposed as possible candidates for weak interacting massive particles (WIMP) of Dark Matter.
We present a model of vector dark matter that interacts through a low-mass vector mediator based on the Higgsing of an SU(2) dark sector. The dark matter is charged under a U(1) gauge symmetry. Even though this symmetry is broken, the residual global symmetries of the theory prevent dark matter decay. We present the behavior of the model subject to the assumption that the dark matter abundance is due to thermal freeze out, including self-interaction targets for small scale structure anomalies and the possibility of interacting with the Standard Model through the vector mediator.
Dark matter, one of the important portion of the universe, could affect the visible matter in neutron stars. An important physical feature of dark matter is due to the spin of dark matter particles. Here, applying the piecewise polytropic equation of state for the neutron star matter and the equation of state of spin polarized self-interacting dark matter, we investigate the structure of neutron stars which are influenced by the spin polarized self-interacting dark matter. The behavior of the neutron star matter and dark matter portions for the stars with different values of the interaction be…
Recently has been showed that models which consider self-interacting particles as dark matter candidates can be able to account all the discrepancies between N-body simulations and astronomical observations of the galactic structure. In the present work we show that the 3-3-1-electroweak model can provide a realistic candidate to this kind of dark matter. This dark matter particle is not arbitrarily imposed and no new symmetry is need for to stabilize it.
The dark matter density distribution in small-scale astrophysical objects may indicate that dark matter is self-interacting, while observations from clusters of galaxies suggest that the corresponding cross section depends on the velocity. Using a model-independent approach, we show that resonant self-interacting dark matter (RSIDM) can naturally explain such a behavior. In contrast to what is often assumed, this does not require a light mediator. We present explicit realizations of this mechanism and discuss the corresponding astrophysical constraints.
We investigate the global dynamics of the universe within the framework of the Interacting Dark Matter (IDM) scenario. Considering that the dark matter obeys the collisional Boltzmann equation, we can obtain analytical solutions of the global density evolution, which can accommodate an accelerated expansion, equivalent to either the {\em quintessence} or the standard $Λ$ models. This is possible if there is a disequilibrium between the DM particle creation and annihilation processes with the former process dominating, which creates an effective source term with negative pressure. Comparing the…
Self-interacting dark matter has been suggested in order to overcome the difficulties of the Cold Dark Matter model on galactic scales. We argue that a scalar gauge singlet coupled to the Higgs boson, which could lead to an invisibly decaying Higgs, is an interesting candidate for this self-interacting dark matter particle. We also present estimates on the abundance of these particles today as well as consequences to non-Newtonian forces.
We consider a simple renormalizable model providing a UV completion for dark matter whose interactions with the Standard Model are primarily via the gluons. The model consists of scalar dark matter interacting with scalar colored mediator particles. A novel feature is the fact that (in contrast to more typical models containing dark matter whose interactions are mediated via colored scalars) the colored scalars typically decay into multi-quark final states, with no associated missing energy. We construct this class of models and examine associated phenomena related to dark matter annihilation,…
We reinterpret the results of the direct searches for dark matter in terms of milli-interacting dark particles. The model reproduces the positive results from DAMA/LIBRA and CoGeNT and is consistent with the absence of signal in the XENON100, CDMS-II/Ge and LUX detectors. Dark atoms, interacting with standard atoms through a kinetic mixing between photons and dark photons and a mass mixing of σ mesons with dark scalars, diffuse elastically in terrestrial matter where they deposit all their energy. Reaching underground detectors through gravity at thermal energies, they form bound states with n…
Dark energy might directly interact with cold dark matter. However, in such a scenario, an early-time large-scale instability occurs occasionally, which may be due to the incorrect treatment for the pressure perturbation of dark energy as a nonadiabatic fluid. To avoid this nonphysical instability, we establish a new framework to correctly calculate the cosmological perturbations in the interacting dark energy models. Inspired by the well-known parametrized post-Friedmann approach, the condition of the dark energy pressure perturbation is replaced with the relationship between the momentum den…
A thick dark matter disk is predicted in cold dark matter simulations as the outcome of the interaction between accreted satellites and the stellar disk in Milky Way sized halos. We study the effects of a self-interacting thick dark disk on the energetic neutrino flux from the Sun. We find that for particle masses between 100 GeV and 1 TeV and dark matter annihilation to heavy leptons either the self-interaction may not be strong enough to solve the small scale structure motivation or a dark disk cannot be present in the Milky Way.
We present a unifying treatment of dark energy and modified gravity that allows distinct conformal-disformal couplings of matter species to the gravitational sector. In this very general approach, we derive the conditions to avoid ghost and gradient instabilities. We compute the equations of motion for background quantities and linear perturbations. We illustrate our formalism with two simple scenarios, where either cold dark matter or a relativistic fluid is nonminimally coupled. This extends previous studies of coupled dark energy to a much broader spectrum of gravitational theories.
We consider a light dark matter candidate which is produced by the freeze-out mechanism with $3\rightarrow2$ annihilations, the so called Strongly Interacting Massive Particles (SIMPs). SIMPs are identified as dark pions in dark chiral perturbation theory (ChPT) where both light mass and strong coupling needed for SIMPs can be realized by strong dynamics. In QCD-like theories with $SU(3)_L \times SU(3)_R /SU(3)_V$ flavor symmetry, including dark vector mesons in the hidden local symmetry scheme, we illustrate that dark vector mesons unitarize the dark ChPT efficiently, thus determine the corre…
Interactions within the cosmic medium modify its equation of state. We discuss implications of interacting dark energy models both for the spatially homogenous background and for the perturbation dynamics.
Interacting dark energy and the holographic principle offer a possible way of addressing the cosmic coincidence problem as well as accounting for the size of the dark energy component. The equilibrium points of the Friedmann equations which govern the evolution behavior of dark energy, matter, and curvature components can determine the qualitative behavior of the cosmological models. These possible equilibria and their behavior are examined in a general framework, and some illustrative examples are presented.
We examine the phenomenology of a simplified model of fermionic dark matter coupled to a light scalar mediator carrying lepton number 2. We find that the mediator can be very light and still consistent with laboratory and cosmological bounds. This model satisfies the thermal relic condition for natural values of dimensionless coupling constants and admits a mediator in the $10 - 100 ~\text{MeV}$ mass range favored by small scale structure observations. As such, this model provides an excellent candidate for self-interacting dark matter.
In this paper I discuss some of the phenomenologies of models of the dark energy interacting with the ordinary matter. After a very brief review about the current constraint on the equation of the state of the dark energy from the SN and a new scenario of dark energy {\it the Quintom}, I present models of Quintessential Baryo(Lepto)genesis, Quintessino dark matter and mass varying neutrinos in details.
Cosmological models with cold dark matter composed of weakly interacting particles predict overly dense cores in the centers of galaxies and clusters and an overly large number of halos within the Local Group compared to actual observations. We propose that the conflict can be resolved if the cold dark matter particles are self-interacting with a large scattering cross-section but negligible annihilation or dissipation. In this scenario, astronomical observations may enable us to study dark matter properties that are inaccessible in the laboratory
We suggest that a weak isotriplet composite scalar possessing an unbroken U(1) global symmetry naturally arises in technicolor models leading to an interesting type of dark matter candidate: the iTIMP. We propose explicit models of the iTIMP, study earth based constraints and suggest possible collider signals.
This work studies the self-interacting dark matter (SIDM) scenario in the general NMSSM and beyond, where the dark matter is a Majorana fermion and the force mediator is a scalar boson. An improved analytical expression for the dark matter (DM) self-interacting cross section which takes into account the Born level effects is proposed. Due to the large couplings and light mediator in SIDM scenario, the DM/mediator will go through multiple branchings if they are produced with high energy. Based on the Monte Carlo simulation of the showers in the DM sector, we obtain the multiplicities and the sp…
A new dark energy model, named "agegraphic dark energy", has been proposed recently, based on the so-called Károlyházy uncertainty relation, which arises from quantum mechanics together with general relativity. In this note, we extend the original agegraphic dark energy model by including the interaction between agegraphic dark energy and pressureless (dark) matter. In the interacting agegraphic dark energy model, there are many interesting features different from the original agegraphic dark energy model and holographic dark energy model. The similarity and difference between agegraphic dark …
Several observational constraints are imposed on the interacting holographic model of Dark Energy and Dark Matter. First we use the age parameter today, as given by the WMAP results. Subsequently, we explained the reason why it is possible, as recently observed, for an old quasar to be observed in early stages of the universe. We discuss this question in terms of the evolution of the age parameter as well as in terms of the structure formation. Finally, we give a detailed discussion of the constraints implied by the observed CMB low $\ell$ suppression. As a result, the interacting holographic …
In this work we show that the supersymmetric economical SU(3)_C X SU(3)_L X U(1)_X (3-3-1) gauge model has a realistic candidate for self-interacting dark matter. In the model under consideration, the right-handed sneutrino is in bottom of the triplet, which is a singlet of the Standard Model SU(2)_L group. In addition, the right-handed sneutrino is the lightest slepton. By these properties, the right-handed sneutrino is weakly interacting with the Standard Model and stable without introduction of extra symmetry. From the Spergel-Steinhardt condition, the typical mass limit $\leq 10 $ MeV is d…
The light mediator scenario of self-interacting dark matter is strongly constrained in many ways. After summarizing the various constraints, we discuss minimal options and models which allow to nevertheless satisfy all these constraints. One straightforward possibility arises if the dark matter and light mediator particles have a temperature sizably smaller than the SM particles. Another simple possibility arises if dark matter doesn't annihilate dominantly into a pair of light mediators but into heavier particles. Both possibilities are discussed with scalar as well as vector boson light medi…
Hannestad and Scherrer analysed self-interacting Warm and Hot Dark Matter and found power spectra in disagreement with previous papers. We argue that they include self-interactions in a weak-coupling approximation, as for photons after recombination. The ``tightly coupled'' approximation used for pre-recombination photons, and previous discussions of self-interacting HMD, would have been more appropriate. Their approximation generates a Boltzmann hierarchy leading to a stiff system of equations. Furthermore contamination by gauge modes could invalidate their results.
We consider different types of Q-balls as self-interacting dark matter. For the Q-balls to act as the dark matter of the universe they should not evaporate, which requires them to carry very large charges; depending on the type, the minimum charge could be as high as Q \sim 10^{33} or the Q-ball coupling to ordinary matter as small as \sim 10^{-35}. The cross-section-to-mass ratio needed for self-interacting dark matter implies a mass scale of m \sim O(1) MeV for the quanta that the Q-balls consist of, which is very difficult to achieve in the MSSM.
It has been shown by many independent studies that the cold dark matter scenario produces singular galactic dark halos, in strong contrast with observations. Possible remedies are that either the dark matter is warm so that it has significant thermal motion or that the dark matter has strong self interactions. We have combined these ideas to calculate the linear mass power spectrum and the spectrum of cosmic microwave background (CMB) fluctuations for self-interacting warm dark matter. Our results indicate that such models have more power on small scales than is the case for the standard warm …
Recent, very accurate simulations of galaxy formation have revealed that the standard cold dark matter model has great difficulty in explaining the detailed structure of galaxies. One of the major problems is that galactic halos are too centrally concentrated. Dark matter self-interactions have been proposed as a possible means of resolving this inconsistency. Here, we investigate quantitatively the effect of dark matter self interactions on formation of galactic halos. Our numerical framework is extremely simple, while still keeping the essential physics. We confirm that strongly self-interac…
In this paper we consider very weakly interacting and ultra light scalar and pseudoscalar dark matter candidates. We show that quantum gravity has important implications for such models and that the masses of the singlet scalar and pseudoscalar fields must be heavier than $3\times 10^{-3}$ eV. However, if they are gauged, their masses could be much lighter and as light as $10^{-22}\, {\rm eV}$. The existence of new gauge forces in the dark matter sector can thus be probed by atomic clocks or quantum sensors experiments.
We study evolution of self-interacting dark matter (SIDM) subhalos in the Milky Way (MW) tidal field. The interaction between the subhalos and the MW's tides lead to more diverse dark matter distribution in the inner region, compared to their cold dark matter counterparts. We test this scenario with two MW satellite galaxies, Draco and Fornax, opposite extremes in the inner dark matter content, and find that they can be accommodated within the SIDM model proposed to explain the diverse rotation curves of spiral galaxies in the field.
