Workshop on Very Light Dark Matter 2021

Session

Wednesday AM

29 Sept 2021, 10:00

Online

Conveners

Wednesday AM

• Tomohiro Fujita

30. The Ubiquitous Axion in Quantum Gravity

Matthew Reece

29/09/2021, 10:00

Invited

Axion-like fields appear in many string theory constructions. I will discuss a proposed explanation for why they are so ubiquitous: they play a crucial role in eliminating would-be global symmetries from the theory. This perspective also gives a new perspective on axion interactions with magnetic monopoles. I will explain how magnetic monopole loops give rise to an axion potential.

31. Constraints to SFDM from Internal Structure and Orbital Parameters of Milky Way Satellites

Victor Robles

29/09/2021, 10:40

Recent measurements of both internal density structure and global orbital properties of Milky Way dwarf galaxies hold the promise of tightly constraining or ruling out the allowed parameter space of ultra-light (scalar field) dark matter (SFDM) models. Recent SFDM simulations evolving the Schroedinger-Poisson system have led to new insights into the structure of isolated scalar field dark...

32. On the Random Motion of Nuclear Objects in a Fuzzy Dark Matter Halo

Dhruba Dutta Chowdhury

29/09/2021, 11:15

Fuzzy Dark Matter (FDM), consisting of ultralight bosons (m_b ~ 10^{-22} eV), is an intriguing alternative to Cold Dark Matter. Numerical simulations that solve the Schrodinger-Poisson (SP) equation show that FDM halos consist of a central solitonic core, which is the ground state of the SP equation, surrounded by an envelope of interfering excited states. These excited states also interfere...

33. Bounding long-range force from dark matters with binary pulsars

Lijing Shao

29/09/2021, 11:40

The orbital dynamics of binary pulsars is influenced by a possible long-range fifth-force from the Galactic dark matter distribution. It is constrained with current binary pulsar experiments, and will be bound further with binary pulsar systems near the Galactic Center. [Shao, Wex, Kramer, PRL 120 (2018) 241104]

46. Axion dark matter and inflation scale

Wen Yin

29/09/2021, 11:55

I show that the upper bound of the classical QCD axion window can be significantly relaxed with (not too) low-scale inflation. If the Gibbons-Hawking temperature during inflation is lower than the QCD scale and the inflation lasts long enough, the initial QCD axion misalignment angle follows the Bunch-Davies distribution. The distribution is peaked at the strong CP conserving minimum if there...

47. Asteroid Tracking Array and Space Quantum Technology for Fundamental Physics

Yu-Dai Tsai

29/09/2021, 12:10

We study for the first time the possibility of probing long-range fifth forces utilizing asteroid astrometric data, via the fifth force-induced orbital precession. We examine nine Near-Earth Object (NEO) asteroids whose orbital trajectories are accurately determined via optical and radar astrometry. Focusing on a Yukawa-type potential mediated by a new gauge field (dark photon) or a...