Conveners
Wednesday PM
- Ippei Obata
-
Hei Yin Jowett Chan29/09/2021, 14:00
In simulations of Fuzzy Dark Matter (FDM) model, we always found gravitationally collapsed object composed of a solitonic core locating within a virialized halo. Although a measured relation between the core and halo mass, from simulation, is often adopted to make observational constraints on the particle mass, there is still a disagreement on the relation between different groups. To fully...
Go to contribution page -
Jonathan Ouellet29/09/2021, 14:25
The particle nature of Dark Matter (DM) is one of the most important open questions in particle physics today. Axions, and axion like particles (ALPs), more generally, have emerged as one of the leading candidates to to explain the DM abundance of the universe. Experimental searches for axion DM (aDM) have traditionally searched in a narrow mass band between 1~100 ueV using microwave cavity...
Go to contribution page -
Silvia Gasparotto29/09/2021, 14:50Invited
A recent measurement of the non-zero isotropic birefringence angle with a 2.4 sigma level in Planck 2018 polarization data opens a tantalizing window for testing the parity-violating extension of the Standard Model. In this talk, I will explain the measurement of cosmic birefringence and discuss its implications for dark matter and dark energy models in the context of axion physics.
Go to contribution page -
Yong Xu29/09/2021, 16:05
In this talk, we present the phenomenology of QCD axion dark matter in a nonstandard cosmological era triggered by PBHs that fully evaporate before the onset of BBN. We show that PBHs have a strong impact on the dark matter produced via the misalignment mechanism. First, the oscillation temperature of axions reduces if there is a PBH dominated era, and second, PBH evaporation injects entropy,...
Go to contribution page -
Yourong Wang29/09/2021, 16:20
I will discuss simulations a massive objects interacting with ULDM, using an extension of the PyUltraLight code. Simulations of a point mass moving in a uniform background and a SMBH moving within a ULDM soliton broadly confirm simple estimates of dynamical friction timescales. However, in addition to generating complex inhomogeneities, SMHB-ULDM interactions excite coherent ``breathing...
Go to contribution page -
Kazumi Hata29/09/2021, 16:35
KamLAND is an ultra-low BG detector with 1000 tons of liquid scintillator.
Taking advantage of this characteristic, we have made great achievements in the neutrino detection, and it can be fully utilized for dark matter search.
In this talk, the result of searching MeV-scale DM self-annihilation to neutrino production in KamLAND. No significant excess was found over the background...
Go to contribution page -
Shota Nakagawa29/09/2021, 16:50
Recently, the Planck 2018 polarization data of cosmic microwave background (CMB) radiation suggested the non-zero rotation angle of CMB polarization plane, which is called cosmic birefringence. Cosmic birefringence is predicted if an axion-like particle (ALP) moves after the recombination. We show that this naturally happens if the ALP is coupled to the dark matter density because it then...
Go to contribution page -
Saurya Das29/09/2021, 17:05
We show that Dark Matter consisting of ultralight bosons in a Bose-Einstein condensate induces, via its quantum potential, a small positive cosmological constant which is close to the observed value. This explains why the densities of Dark Matter and Dark Energy are approximately equal.
Go to contribution page -
Sebastian Hoof
I will report on or recent results on creating catalogues of hadronic, aka KSVZ, axion models. In particular, when phenomenological selection criteria are taken into account, we find a finite number of possible anomaly ratios E/N, and hence a finite number of hadronic axion models at any given mass. The number of different E/N values is between 12 and 820, depending on the amount of freedom...
Go to contribution page