Conveners
Ultralight dark matter
- Benjamin Roberts
Ultralight dark matter
- Igor Samsonov (UNSW)
We consider scalar field dark matter model with a dilaton-like interaction with the electromagnetic field. If the mass of this scalar field falls within the range of hundreds of MHz, it may be detected using cavity resonator techniques similar to those used in the search of the axion dark matter in the ADMX and ORGAN experiments. We show that existing cavity resonators employed in experiments...
The mystery of dark matter (DM) is a long-standing issue in physics, with numerous dedicated experiments returning no confirmed detections. With the constantly increasing sensitivity of direct detection experiments, much of the parameter space for Weakly Interacting Massive Particles (WIMPs) has been ruled out. However, low mass (sub-GeV) WIMP-like particles are less researched and yet to be...
We study the prospects of using several metastable excited states of Cu II, Yb III, Hf II, Hf IV, and W VI ions as clock transitions in optical clocks. The transitions between ground and metastable states in these systems are the $s-d$ transitions which ensure high sensitivity to the variation of the fine structure constant. Cooling E1 transitions are available. Energy levels, $\text { Landé...
We shall explain why we expect atomic spectra to be sensitive to new bosons, like Z' boson and axion. Such bosons can be exchanged between the known particles. We will present new bounds on the properties of such bosons, using spectra of antiprotonic helium, muonium, positronium, helium, and hydrogen. We will show how to construct such bounds, including one using pseudovector interaction which...
Fundamental constants such as masses and coupling constants of elementary particles can have small temporal and spatial variations in the scalar field dark matter model. These variations entail time oscillations of other constants, such as the Bohr and nuclear magnetons, Bohr radius and the hyperfine structure constant. In the presence of an external magnetic field, these oscillations induce...
Ultralight scalar dark matter may induce apparent oscillations of the muon mass, which may be directly probed via temporal shifts in the spectra of muonium and muonic atoms. Existing datasets and ongoing spectroscopy measurements with muonium are capable of probing scalar-muon interactions that are up to 8 orders of magnitude feebler than astrophysical bounds. Ongoing free-fall experiments...
Axions have been considered the most favored solution to both the strong-CP problem and the dark matter mystery. Many experimental searches that rely on the axion-photon conversion under a strong magnetic field utilize the haloscope technique that is sensitive in the microwave region. We, the Center for Axion and Precision Physics Research (CAPP) of the Institute for Basic Science (IBS), have...
In the scenario in which the axion is born after inflation, understanding the abundance and distribution of axion dark matter requires dedicated numerical simulations. We study the complex dynamics of the axion field's evolution, including the scaling of the axion cosmic string network, the decay of domain walls, and the gravitational formation of miniclusters by means of lattice and N-body...
We simulate the gravitational dynamics of a massive object interacting with ultralight/fuzzy dark matter (ULDM/FDM), nonrelativistic quantum matter described by the Schrödinger-Poisson equation.
We first consider a point mass moving in a uniform background, and then a supermassive black hole (SMBH) moving within a ULDM soliton. After replicating simple dynamical friction scenarios to...
Searching for space-time variations of the constants of Nature is a promising way to search for new physics beyond general relativity and the standard model motivated by unification theories and models of dark matter and dark energy. We propose a new way to search for a variation of the fine-structure constant using measurements of late-type evolved giant stars from the S star cluster orbiting...
