### Conveners

#### Interacting Dark Matter: Block 1

- Nikolaos Mavromatos (King's College London, Physics Department)

#### Interacting Dark Matter: Block 2

- Nikolaos Mavromatos (King's College London, Physics Department)

### Description

The session is devoted to the physics of all possible aspects of interacting dark matter, including self interactions of dark matter and their cosmological consequences, or interactions of dark matter with ordinary matter and their consequences. Various types of dark matter in various models, including supersymmetry, are considered. Dark matter searches also constitute part of the session's subject.

I will review the present status of massive and clustered PBH that may constitute all of the Dark Matter in the Universe.

Fuzzy dark matter (FDM) is a general term for the lightest possible dark matter particle. FDM is distinct from CDM in manifesting wavelike effects on cosmic scales, which lead to a vast array of methods to probe this model. Across more than 20 orders of magnitude, only two windows windows remain where FDM can constitute the entirety of the dark matter. I will discuss how these windows are...

We discuss the problem of formation of dark matter (DM) halos from the principle of maximum (coarse-grained) entropy, when including for the quantum nature of the DM particles. In the case of DM fermions, such a formation mechanism involves for (long-range) particle-particle interactions, and can lead to a most-likely phase-space distribution accounting for the Pauli-principle as well as...

In this talk, I will discuss a cosmological model with dark energy – dark matter interaction. Demanding that the interaction strength $Q_{\nu}$ in the dark sector must have a field theory description, a unique form of interaction strength can be obtained. I will show the equivalence between the fields and fluids for the $f(R,\chi)$ model where $f$ is an arbitrary, smooth function of $R$ and...

Dark matter scenarios are being tested at the LHC in the general-purpose experiments through *promptly* decaying states. In parallel, new dedicated detectors have been proposed for the LHC to probe dark matter portal theories predicting *long-lived* particles that decay away from the interaction point: MoEDAL-MAPP, MoEDAL-MALL, FASER, CODEX-b, MATHUSLA, AL3X, ANUBIS, milliQan. In addition, the...

MoEDAL-MAPP is a pioneering experiment designed to search for highly ionizing (HIP), feebly interacting (mQP) and long-lived particle (LLP) avatars of new physics in p-p and heavy-ions collisions at the LHC. The MoEDAL baseline detector first took data at LHC’s Run-2. This detector was dedicated to the search for HIPs, such as magnetic monopoles or massive (pseudo-)stable charged particles,...

Collapsed structures, or halos, formed in models with self-interacting dark matter (SIDM) have unique properties that distinguish them from structures formed in cold dark matter (CDM). In particular, momentum and energy exchange inside SIDM halos drives the formation of a central core that may eventually undergo core collapse, such that the halo becomes extremely centrally concentrated. We...

The Lambda-Cold Dark Matter ($\Lambda$CDM) model agrees with most of the cosmological observations, but has some hindrances from observed data at smaller scales such as galaxies. Recently, Berezhiani and Khoury proposed a new theory involving interacting superfluid dark matter with three model parameters in \cite{khoury2015}, which explains galactic dynamics with great accuracy. In the present...

The cosmological constant is usually associated with the notion of vacuum energy density in quantum field theory (QFT). Whether $\Lambda$ is a rigid quantity or a dynamical variable has been a matter of debate for many years, especially after the introduction of the general notion of dark energy (DE). In an expanding universe one may expect that $\Lambda$, and the corresponding vacuum...

A recently proposed Dynamical Space-time Cosmology (DSC) that unifies dark

energy and dark matter is studied. The general action of this scenario includes a Lagrange

multiplier, which is coupled to the energy momentum tensor and a scalar field which is different

from quintessence. First for various types of potentials we implement a critical point analysis

and we find solutions which lead...

In special relativity (SR) and in general relativity, the energy tensors of a charged medium and its electromagnetic field, ${\bf T}_\mathrm{chg}$ and ${\bf T}_\mathrm{field}$, add to give the total energy tensor ${\bf T}$ obeying $T^{\mu \nu }_{\ \, ;\nu}=0$: one has

${\bf T} = {\bf T}_\mathrm{chg} + {\bf T}_\mathrm{field}$. (1)

In the "scalar ether theory of gravitation" (SET),...

In this talk I will show up-to-date cosmological constraints on the interactions between dark matter and the component that might be driving the current acceleration of the universe. In particular, I will explain what is the status of two different theoretical models: (i) coupled quintessence, with a fifth force between dark matter particles, mediated by a scalar field that plays the role of...

In this talk, I’ll discuss ideas for new approaches in the hunt for light dark matter was gas-based detectors. I’ll show that the sensitivity that may be achievable through the process of electron ionisation of gas targets in a Spherical Proportional Counter in very promising, going beyond current exclusion limits. I'll also pay particular attention to the potential benefits of molecular gas targets.

The Fornax dSph displays a variety of globular cluster at projected radii that seem at odds with the presence of a NFW profile. I will quantify this 'anomaly' (at the level of a 25% tuning) and discuss how different DM models can alleviate it.

We consider physics beyond the standard model, which incorporates a see-saw mechanism for neutrino masses. This physics is augmented by incorporating gravitational degrees of freedom ( dilaton, graviton and Kalb-Ramond field) found in the theory of closed strings. In the inflationary era the gravitational degrees of freedom and inflatons dominate. Due to quantum effects there is a...