Conveners
DM IV
- Felix Kling (University of Arizona)
The conventional misalignment mechanism can explain axion dark matter only in a limited mass range and face various difficulties for vector dark matter that we refer to as dark photons. We propose new dark matter production mechanisms for axions and dark photons via parametric resonance and tachyonic instability, respectively. These ideas expand the parameter space to the regions of interest...
Ultra-light scalar theories with repulsive self-interactions admit boson stars with large compactness. I will show the origin of the maximum mass of spherically symmetric stable boson stars, which manifests only in the full equations of motion in curved space-time, but not in the approximated Schrödinger-Newton equations. The backreaction of the curvature on the scalars acts as an additional...
Exotic compact objects such as primordial black holes, boson star, etc., are theoretically predicted to exist and can make interesting dark matter candidates,
yet with no definitive observational evidence for their existence. This talk will
discuss the method of using gravitational waves from the extreme mass ratio inspiral, formed by an ECO and a supermassive black hole in the center of each...
Primordial black holes (PBHs) with a mass from $10^{-16}$ to $10^{-11}\,M_\odot$ may comprise 100% of dark matter. Due to a combination of wave and finite source size effects, the traditional microlensing of stars does not probe this mass range. In this talk, we point out that X-ray pulsars with higher photon energies and smaller source sizes are good candidate sources for microlensing for...
We show how a simple dissipative dark sector can form exotic compact objects that vary in size from a few to millions of solar masses. These exotic compact objects may be detected and their properties measured at new high-precision astronomical observatories, giving insight into the particle nature of the dark sector without the requirement of non-gravitational interactions with the visible sector.
Mirror sectors -- hidden sectors that are approximate copies of the Standard Model -- are a generic prediction of many models, notably the Mirror Twin Higgs model. Such models can have a rich cosmology and many interesting detection signatures beyond the realm of colliders. In this talk, I will focus on the possibility that mirror matter can form stars which undergo mirror nuclear fusion in...
"Dark quark nuggets", a lump of dark quark matter, can be produced in the early universe for a wide range of confining gauge theories and serve as a macroscopic dark matter candidate. The two necessary conditions, a nonzero dark baryon number asymmetry and a first-order phase transition, can be easily satisfied for many asymmetric dark matter models and QCD-like gauge theories with a few...
The conjectured bound state of uuddss in color-spin-flavor singlet can be a stable and compact particle, the sexaquark. Such a particle formed from QCD plasma in the early universe explains the observed dark matter abundance and can potentially resolve the 7Li puzzle. We will argue that a stable sexaquark may live in a rather wide mass window, either above two nucleon mass or below, because...
