Workshop on Very Light Dark Matter 2023

Session

Morning session-1

Mar 28, 2023, 11:05 AM

Mario Royal Kaikan (Chino, Nagano) + Online

Conveners

Morning session-1

• Ippei Obata

Morning session-1

• Elisa Ferreira

Morning session-1

• Nagisa Hiroshima

27. Dark Matter and Quantum Gravity

Toshifumi Noumi

3/28/23, 11:05 AM

Recent studies in the Swampland Program are pointing a possibility that quantum gravity constraints can be used to curve out the vast theory space of dark matters theoretically. In this talk, I will introduce our recent attempts to this direction based on unitarity of gravitational scattering amplitudes. In particular, I will discuss dark photon scenarios as an illustrative example and also...

14. Fuzzy Vector Dark Matter

Kaloian Lozanov

3/28/23, 11:45 AM

We will review the recent progress in the understanding of the non-relativistic weak-gravity dynamics of massive dark vector fields and whether they can play the role of dark matter in the late universe. We will also discuss different production mechanisms of vector dark matter in the primordial universe.

5. Production of very light dark photon dark matter

Naoya Kitajima

3/28/23, 12:05 PM

In this talk, I will show several production mechanisms of light dark photon dark matter in the early universe. It contains (i) resonant dark production from axion oscillation, (ii) dark photon emission form the collapse of cosmic string loops, (iii) misalignment production of coherently oscillating dark photons. Observational implications will also be discussed.

6. Stability of domain wall network with initial inflationary fluctuations, and its implications for cosmic birefringence

Diego Gonzalez

3/28/23, 12:25 PM

We study the formation and evolution of domain walls with initial inflationary fluctuations by numerical lattice calculations, correctly taking into account correlations on superhorizon scales. We find that, contrary to the widely-held claim, the domain wall network exhibits remarkable stability even when the initial distribution is largely biased toward one of the minima. This is due to the...

26. Stochastic Properties of Ultralight Scalar Fields

Mariangela Lisanti

3/29/23, 9:00 AM

Ultralight axionlike particles are well-motivated dark matter candidates that are the target of numerous direct detection efforts. In the vicinity of the Solar System, such particles can be treated as oscillating scalar fields. The velocity dispersion of the Milky Way determines a coherence time of about
10
6
oscillations, beyond which the amplitude of the axion field fluctuates...

1. Gravitational impact of Supernovae in Ultra-light Axion Dark Matter halos

Victor H. Robles

3/29/23, 9:40 AM

One of the viable dark matter models is the Ultra-light Scalar field Dark Matter where it assumes an ultra-light axion-like particle of mass 10^(-22)eV. Current cosmological (dark matter only) simulations reveal that the dark matter halos formed in this model have a unique wave-like structure and a characteristic soliton at their centers. In this talk, I will discuss how these inners solitons...

3. Tidal Love numbers for environmental black-hole mergers

Valerio De Luca

3/29/23, 10:00 AM

Tidal Love numbers describe the deformability of compact objects under the presence of external tidal perturbations, and are found to be exactly zero for black holes. We discuss about the scenario of black holes dressed with an ultralight scalar field, addressing their detectability at future gravitational wave experiments.

31. Multi-prong searches for light dark matter

Nancy Aggarwal

3/30/23, 9:00 AM

20. Bounds on Long-lived Dark Matter Mediators from Neutron Stars

Thong Nguyen

3/30/23, 9:40 AM

Neutron stars close to the Galactic center are expected to swim in a dense background of dark matter. For models in which the dark matter has efficient interactions with neutrons, they are expected to accumulate their own local cloud of dark matter, making them appealing targets for observations seeking signs of dark matter annihilation. For theories with very light mediators, the dark matter...

21. Sub-GeV dark matter search at ILC beam dumps

Daiki Ueda

3/30/23, 10:00 AM

Light dark matter particles may be produced in electron and positron beam dumps of the International Linear Collider (ILC). We propose an experimental setup to search for such events, the Beam-Dump eXperiment at the ILC (ILC-BDX). The setup consists of a muon shield placed behind the beam dump, followed by a multi- layer tracker and an electromagnetic calorimeter. The calorimeter can detect...

15. Dark photon superradiance

Nils Siemonsen

I will describe the electrodynamics of a kinetically mixed dark photon cloud that forms through superradiance around a spinning black hole, and outline strategies to search for the resulting multi-messenger signals. A dark photon superradiance cloud sources a rotating dark electromagnetic field which, through kinetic mixing, induces a rotating visible electromagnetic field. Standard model...