A White Paper On Kev Sterile Neutrino Dark Matter

We present a comprehensive review of keV-scale sterile neutrino Dark Matter, collecting views and insights from all disciplines involved - cosmology, astrophysics, nuclear, and particle physics - in each case viewed from both theoretical and experimental/observational perspectives. After reviewing the role of active neutrinos in particle physics, astrophysics, and cosmology, we focus on sterile neutrinos in the context of the Dark Matter puzzle. Here, we first review the physics motivation for sterile neutrino Dark Matter, based on challenges and tensions in purely cold Dark Matter scenarios. We then round out the discussion by critically summarizing all known constraints on sterile neutrino Dark Matter arising from astrophysical observations, laboratory experiments, and theoretical considerations. In this context, we provide a balanced discourse on the possibly positive signal from X-ray observations. Another focus of the paper concerns the construction of particle physics models, aiming to explain how sterile neutrinos of keV-scale masses could arise in concrete settings beyond the Standard Model of elementary particle physics. The paper ends with an extensive review of current and future astrophysical and laboratory searches, highlighting new ideas and their experimental challenges, as well as future perspectives for the discovery of sterile neutrinos.

This book is a new look at one of the hottest topics in contemporary science, Dark Matter. It is the pioneering text dedicated to sterile neutrinos as candidate particles for Dark Matter, challenging some of the standard assumptions which may be true for some Dark Matter candidates but not for all. So, this can be seen either as an introduction to a specialized topic or an out-of-the-box introduction to the field of Dark Matter in general. No matter if you are a theoretical particle physicist, an observational astronomer, or a ground based experimentalist, no matter if you are a grad student or an active researcher, you can benefit from this text, for a simple reason: a non-standard candidate for Dark Matter can teach you a lot about what we truly know about our standard picture of how the Universe works.

This book is a new look at one of the hottest topics in contemporary science, Dark Matter. It is the pioneering text dedicated to sterile neutrinos as candidate particles for Dark Matter, challenging some of the standard assumptions which may be true for some Dark Matter candidates but not for all. So, this can be seen either as an introduction to a specialized topic or an out-of-the-box introduction to the field of Dark Matter in general. No matter if you are a theoretical particle physicist, an observational astronomer, or a ground based experimentalist, no matter if you are a grad student or an active researcher, you can benefit from this text, for a simple reason: a non-standard candidate for Dark Matter can teach you a lot about what we truly know about our standard picture of how the Universe works.

A self-contained guide to the role played by neutrinos in the Universe and how their properties influence cosmological and astrophysical observations.

Describes the dark matter problem in particle physics, astrophysics and cosmology for graduate students and researchers.

Non-standard interactions (NSI) between active neutrinos (neutrinos belonging to the Standard Model) have the potential to modify the production of a fourth type of keV-scale mass neutrino (called "sterile"), due to active-sterile neutrino oscillations in the early Universe, a process known as the Dodelson-Widrow mechanism (DW). Through this modified DW mechanism, enough sterile neutrinos could be produced to account for the whole of the dark matter. This type of dark matter production occurred before big bang nucleosynthesis (BBN), an era just before the temperature of the Universe settled to 5 MeV, which is currently unknown. Thus, this type of dark matter production can be explored with different pre-BBN cosmological models. Taking into consideration the uncertainties in the pre-BBN cosmology besides the effects of NSI, we may identify a viable parameter space for sterile neutrino searches allowed by astrophysical limits and assess their effect on the range of mixing angles for keV-scale mass sterile neutrino dark matter. Detection of a sterile neutrino could provide insight into the pre-BBN era of the Universe. We find that the combined uncertainties in the early Universe cosmologies, as well as in the active neutrino interactions, significantly expand the allowed parameter space for sterile neutrinos that could constitute the whole of the dark matter. This thesis work will be published in a paper with the same title by C. Chichiri, G. Gelmini, P. Lu and V. Takhistov, already posted as a preprint in the arXiv,e-Print: 2.111.04087[hep-ph], and submitted for publication to the Journal of Cosmology and Astroparticle Physics (JCAP).

This book gathers selected and expanded contributions presented at the 5th Symposium on Space Optical Instruments and Applications, which was held in Beijing, China, on September 5–7, 2018. This conference series is organized by the Sino-Holland Space Optical Instruments Laboratory, a cooperative platform between China and the Netherlands. The symposium focused on key technological problems regarding optical instruments and their applications in a space context. It covered the latest developments, experiments and results on the theory, instrumentation and applications of space optics. The book is split into five main sections: The first covers optical remote sensing system design, the second focuses on advanced optical system design, and the third addresses remote sensor calibration and measurement. Remote sensing data processing and information extraction are then presented, followed by a final section on remote sensing data applications.

The proceedings of MG16 give a broad view of all aspects of gravitational physics and astrophysics, from mathematical issues to recent observations and experiments. The scientific program of the meeting included 46 plenary presentations, 3 public lectures, 5 round tables and 81 parallel sessions arranged during the intense six-day online meeting. All talks were recorded and are available on the ICRANet YouTube channel at the following link: www.icranet.org/video_mg16.These proceedings are a representative sample of the very many contributions made at the meeting. They contain 383 papers, among which 14 come from the plenary sessions.The material represented in these proceedings cover the following topics: accretion, active galactic nuclei, alternative theories of gravity, black holes (theory, observations and experiments), binaries, boson stars, cosmic microwave background, cosmic strings, dark energy and large scale structure, dark matter, education, exact solutions, early universe, fundamental interactions and stellar evolution, fast transients, gravitational waves, high energy physics, history of relativity, neutron stars, precision tests, quantum gravity, strong fields, and white dwarf; all of them represented by a large number of contributions.The online e-proceedings are published in an open access format.