Quark Nugget Dark Matter Model Research Articles

Structure formation paradigm and axion quark nugget dark matter model

We advocate an idea that ``non-baryonic" dark matter in form of nuggets made of standard model quarks and gluons (similar to the old idea of the Witten's strangelets) could play a crucial role in structure formation. The corresponding macroscopically large objects, which are called the axion quark nuggets (AQN) behave as {\it chameleons}: they do not interact with the surrounding material in dilute environment, but they become strongly interacting objects in sufficiently dense environment. The AQN model was invented long ago with a single motivation to explain the observed similarity $\Omega_{\rm DM}\sim \Omega_{\rm visible}$ between visible and DM components. This relation represents a very generic feature of this framework, not sensitive to any parameters of the construction. We argue that the strong visible-DM interaction may dramatically modify the conventional structure formation pattern at small scales to contribute to a resolution of a variety of interconnected problems (such as Core-Cusp problem, etc) which have been a matter of active research and debates in recent years. We also argue that the same visible-DM interaction at small scales is always accompanied by a broad band diffuse radiation. We speculate that the recently observed excesses of the UV emission by JWST at high redshifts and by GALEX in our own galaxy might be a direct manifestation of this AQN-induced radiation. We also speculate that the very same source of energy injection could contribute to the resolution of another long standing problem related to the Extragalactic Background Light (EBL) with known discrepancies in many frequency bands (from UV to optical, IR light and radio emissions).

The mysterious diffuse UV radiation and axion quark nugget dark matter model

It has been recently argued [1–3] that there is a strong component of the diffuse far-ultraviolet (FUV) background which is hard to explain by conventional physics in terms of the dust-scattered starlight. We propose that this excess in FUV radiation might be result of the dark matter annihilation events within the so-called axion quark nugget (AQN) dark matter model, which was originally invented for completely different purpose to explain the observed similarity between the dark and the visible components in the Universe, i.e. ΩDM∼Ωvisible. We support this proposal by demonstrating that intensity and the spectral features of the AQN induced emissions are consistent with the corresponding characteristics of the observed excess of the FUV radiation. If the future studies confirm the puzzling characteristics observed in [1–3] it might unlock a much more deeper and fundamental problem of modern cosmology– it may reveal the nature of the dark matter.

The 21 cm absorption line and the axion quark nugget dark matter model

We argue that dark matter in the form of macroscopically large nuggets of standard model quarks and antiquarks can help to alleviate the tension between standard model cosmology and the recent EDGES observation of a stronger than anticipated 21 cm absorption feature. The effect occurs as a result of the thermal emission from quark nugget dark matter at early times and at energies well below the peak of the CMB. Similar radiation at early times may also contribute a fraction of the GHz range excess observed by ARCADE2.

Fast radio bursts and the axion quark nugget dark matter model

We explore the possibility that the Fast Radio Bursts (FRBs) are powered by magnetic reconnection in magnetars, triggered by Axion Quark Nugget (AQN) dark matter. In this model, the magnetic reconnection is ignited by the shock wave which develops when the nuggets' Mach number $M \gg 1$. These shock waves generate very strong and very short impulses expressed in terms of pressure $\Delta p/p\sim M^2$ and temperature $\Delta T/T\sim M^2$ in the vicinity of (would be) magnetic reconnection area. We find that the proposed mechanism produces a coherent emission which is consistent with current data, in particular the FRB energy requirements, the observed energy distribution, the frequency range and the burst duration. Our model allows us to propose additional tests which future data will be able to challenge.

Cosmological axion and a quark nugget dark matter model

We study a dark matter (DM) model offering a very natural explanation of two (naively unrelated) problems in cosmology: the observed relation $\Omega_{\rm DM}\sim\Omega_{\rm visible}$ and the observed asymmetry between matter and antimatter in the Universe, known as the "baryogenesis" problem. In this framework, both types of matter (dark and visible) have the same QCD origin, form at the same QCD epoch, and both proportional to one and the same dimensional parameter of the system, $\Lambda_{\rm QCD}$, which explains how these two, naively distinct, problems could be intimately related, and could be solved simultaneously within the same framework. More specifically, the DM in this model is composed by two different ingredients: the (well- studied) DM axions and (less-studied) the quark nuggets made of matter or antimatter. The focus of the present work is the quantitative analysis of the relation between these two distinct components contributing to the dark sector of the theory determined by $\Omega_{\rm DM}\equiv [\Omega_{\rm DM}(\rm nuggets)+ \Omega_{\rm DM}(\rm axion)]$. We argue that the nugget's DM component always traces the visible matter density, i.e. $\Omega_{\rm DM}(\rm nuggets)\sim\Omega_{\rm visible}$ and this feature is not sensitive to the parameters of the system such as the axion mass $m_a$ or the misalignment angle $\theta_0$. It should be contrasted with conventional axion production mechanism due to the misalignment when $\Omega_{\rm DM}(\rm axion)$ is highly sensitive to the axion mass $m_a$ and the initial misalignment angle $\theta_0$. We also discuss the constraints on this model related to the inflationary scale $H_I$, non-observation of the isocurvature perturbations, $r_T < 0.12$, and also, varies axions search experiments.

Solar Extreme UV radiation and quark nugget dark matter model

We advocate the idea that the surprising emission of extreme ultra violet (EUV) radiation and soft x-rays from the Sun are powered externally by incident dark matter (DM) particles. The energy and the spectral shape of this otherwise unexpected solar irradiation is estimated within the quark nugget dark matter model. This model was originally invented as a natural explanation of the observed ratio Ωdark ∼ Ωvisible when the DM and visible matter densities assume the same order of magnitude values. This generic consequence of the model is a result of the common origin of both types of matter which are formed during the same QCD transition and both proportional to the same fundamental dimensional parameter ΛQCD. We also present arguments suggesting that the transient brightening-like "nanoflares" in the Sun may be related to the annihilation events which inevitably occur in the solar atmosphere within this dark matter scenario.

Quark nugget dark matter: Comparison with radio observations of nearby galaxies

It has been recently claimed that radio observations of nearby spiral galaxies essentially rule out a dark matter source for the galactic haze. Here we consider the low energy thermal emission from a quark nugget dark matter model in the context of microwave emission from the galactic centre and radio observations of nearby Milky Way like galaxies. We demonstrate that observed emission levels do not strongly constrain this specific dark matter candidate across a broad range of the allowed parameter space in drastic contrast with conventional dark matter models based on the WIMP paradigm.