Related papers: Hidden Sector Monopole Dark Matter with Matter Dom…
Particle production at the end of a first-order electroweak phase transition may be rather generic in theories beyond the standard model. Dark matter may then be abundantly produced by this mechanism if it has a sizable coupling to the…
The identity of dark matter is being sought with increasingly sensitive and voluminous underground detectors. Recently the XENON1T collaboration reported excess electronic recoil events, with most of these having recoil energies around…
We develop a scenario whereby monopoles in a hidden sector yield a decaying dark matter candidate of interest for the PAMELA and FERMI $e^\pm$ excesses. The monopoles are not completely hidden due to a very small kinetic mixing and a hidden…
We propose a novel scenario to obtain the correct relic abundance for thermally under-produced dark matter. This scenario utilizes a strongly first-order phase transition at temperature $T_{\rm PT}$ that gives rise to dark matter mass $m$.…
We summarize here our studies \cite{Chu:2022xuh,Chu:2023jyb,Chu:2024rrv} on two distinct scenarios for MeV-mass thermal dark matter freeze-out. First, we determine the minimal viable mass for dark matter below tens of MeV, considering…
We consider a minimal extension of the Standard Model with a hidden sector charged under a dark local $U(1)'$ gauge group, accounting simultaneously for light neutrino masses and the observed Dark Matter relic abundance. The model contains…
Within the context of $N=1$ supersymmetric heterotic $M$-theory, we present a "freeze-in" mechanism for producing dark matter via a "moduli portal" between the observable and hidden sectors. It is assumed that the observable sector consists…
Dark matter may be coupled to dark radiation: light degrees of freedom that mediate forces between dark sector particles. Cosmological constraints favor dark radiation that is colder than Standard Model radiation. In models with fixed…
We present a model of dark matter in a warped extra dimension in which the dark sector mass scales are naturally generated without supersymmetry. The dark force, responsible for dark matter annihilating predominantly into leptons, is…
It is well known that stable weak scale particles are viable dark matter candidates since the annihilation cross section is naturally about the right magnitude to leave the correct thermal residual abundance. Many dark matter searches have…
The non-detection of dark matter may be attributed to the dark matter residing in a darker hidden sector. We explore the possibility that a hidden sector produced through the freeze-in mechanism, can further generate an even more hidden…
We propose a novel mechanism for the cosmological production of keV - GeV mass dark matter that interacts with the Standard Model through a small effective magnetic dipole moment. Such an interaction can be radiatively generated if dark…
The early universe could feature multiple reheating events, leading to jumps in the visible sector entropy density that dilute both particle asymmetries and the number density of frozen-out states. In fact, late time entropy jumps are…
We discuss the cosmological production and the successive evolution of the electroweak (Cho-Maison) monopole in the standard model, and estimate the remnant monopole density at present universe. We confirm that, although the electroweak…
We propose a minimal predictive scenario for dark matter and radiative neutrino mass where the relic abundance of dark matter is generated from a hybrid setup comprising of both thermal freeze-out as well as non-thermal freeze-in…
An appealing framework for dark matter is provided by light hidden sectors, below the electroweak scale, feebly coupled to the Standard Model via light mediators. We consider a minimal, predictive model where both the dark matter and the…
We present a model with dark matter in an anomaly-mediated supersymmetry breaking hidden sector with a U(1)xU(1) gauge symmetry. The symmetries of the model stabilize the dark matter and forbid the introduction of new mass parameters. As a…
We propose a new alternative to the Weakly Interacting Massive Particle (WIMP) paradigm for dark matter. Rather than being determined by thermal freeze-out, the dark matter abundance in this scenario is set by dark matter decay, which is…
The universe has evolved through several phases as its various constituents dominated its energy content. Candidate dark matter particles may have undergone freeze-out during any such phase. While the standard freeze-out scenarios have been…
The unitary bound restricts thermal relics to be lighter than $100$ TeV. This work investigates the production of ultraheavy dark matter and WIMPs in the presence of primordial black holes. Firstly, we describe how Hawking evaporation can…