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Alexey Boyarsky

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Publications associées (54)

A White Paper on keV sterile neutrino Dark Matter

Laurent Gastaldo, Igor Tkachev, Alexey Boyarsky, Oleg Ruchayskiy, Julien Lesgourgues, Marco Drewes, Antoine Pierre Emmanuel Alexis Merle, Jan Hamann, Jonathan Leon Wolf

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/o ...

Iop Publishing Ltd2017

The active muon shield in the SHiP experiment

Sebastian Gerlach, Aurelio Bay, Mikhail Chapochnikov, Alexey Boyarsky, Hans Dijkstra, Sun Hee Kim, Oleg Ruchayskiy, Lesya Shchutska, Sergei Smirnov, Inar Timiryasov, Federico Leo Redi, Elena Graverini, Ekaterina Kuznetsova

The SHiP experiment is designed to search for very weakly interacting particles beyond the Standard Model which are produced in a 400 GeV/c proton beam dump at the CERN SPS. An essential task for the experiment is to keep the Standard Model background leve ...

2017

Satellite galaxies in semi-analytic models of galaxy formation with sterile neutrino dark matter

Alexey Boyarsky, Oleg Ruchayskiy

The sterile neutrino is a viable darkmatter candidate that can be produced in the early Universe via non-equilibrium processes, and would therefore possess a highly non-thermal spectrum of primordial velocities. In this paper we analyse the process of stru ...

Wiley-Blackwell2016

Searching for decaying dark matter in deep XMM-Newton observation of the Draco dwarf spheroidal

Alexey Boyarsky, Andrii Neronov, Oleg Ruchayskiy

We present results of a search for the 3.5 keV emission line in our recent very long (similar to 1.4 Ms) XMM-Newton observation of the Draco dwarf spheroidal galaxy. The astrophysical X-ray emission from such dark matter-dominated galaxies is faint, thus t ...

Wiley-Blackwell2016

A facility to search for hidden particles at the CERN SPS: the SHiP physics case

Mikhail Chapochnikov, Anurag Tripathi, Alexey Boyarsky, Oleg Ruchayskiy, Lesya Shchutska, Marco Drewes, Shintaro Eijima, Kyrylo Bondarenko

This paper describes the physics case for a new fixed target facility at CERN SPS. The SHiP (search for hidden particles) experiment is intended to hunt for new physics in the largely unexplored domain of very weakly interacting particles with masses below ...

Institute of Physics2016

Magnetohydrodynamics of chiral relativistic fluids

Alexey Boyarsky, Oleg Ruchayskiy

We study the dynamics of a plasma of charged relativistic fermions at very high temperature T >> m, where m is the fermion mass, coupled to the electromagnetic field. In particular, we derive a magnetohydrodynamical description of the evolution of such a p ...

American Physical Society2015

Decaying dark matter: the case for a deep X-ray observation of Draco

Alexey Boyarsky, Oleg Ruchayskiy

Recent studies of M31, the Galactic Centre (GC), and galaxy clusters have made tentative detections of an X-ray line at similar to 3.5 keV that could be produced by decaying dark matter. We use high-resolution simulations of the Aquarius project to predict ...

Oxford University Press2015

Checking the Dark Matter Origin of a 3.53 keV Line with the Milky Way Center

Alexey Boyarsky, Oleg Ruchayskiy

We detect a line at 3.539 +/- 0.011 keV in the deep exposure data set of the Galactic center region, observed with the x-ray multi-mirror mission Newton. The dark matter interpretation of the signal observed in the Perseus galaxy cluster, the Andromeda gal ...

Amer Physical Soc2015

A new framework for numerical simulations of structure formation

Mikhail Chapochnikov, Claude Becker, Alexey Boyarsky, Oleg Ruchayskiy, Matthieu Schaller

The diversity of structures in the Universe (from the smallest galaxies to the largest superclusters) has formed under the pull of gravity from the tiny primordial perturbations that we see imprinted in the cosmic microwave background. A quantitative descr ...

Oxford Univ Press2014

Potential of the Large Observatory for X-ray Timing telescope for the search for dark matter

Alexey Boyarsky, Oleg Ruchayskiy

Large observatory for x-ray timing (LOFT) is a concept of a next-generation x-ray telescope considered in the context of the "Cosmic Vision" program of the European Space Agency. The Large Area Detector on board of LOFT will be a collimator-type telescope ...

American Physical Society2014

Unidentified Line in X-Ray Spectra of the Andromeda Galaxy and Perseus Galaxy Cluster

Alexey Boyarsky, Oleg Ruchayskiy

We report a weak line at 3.52 +/- 0.02 keV in x-ray spectra of the Andromeda galaxy and the Perseus galaxy cluster observed by the metal-oxide-silicon (MOS) and p-n (PN) CCD cameras of the XMM-Newton telescope. This line is not known as an atomic line in t ...

Amer Physical Soc2014

ORIGIN: metal creation and evolution from the cosmic dawn

Mikhail Chapochnikov, Alexey Boyarsky, Oleg Ruchayskiy, Douglas Cameron Watson, Simone Campana

ORIGIN is a proposal for the M3 mission call of ESA aimed at the study of metal creation from the epoch of cosmic dawn. Using high-spectral resolution in the soft X-ray band, ORIGIN will be able to identify the physical conditions of all abundant elements ...

Springer2012

Self-Consistent Evolution of Magnetic Fields and Chiral Asymmetry in the Early Universe

Alexey Boyarsky, Oleg Ruchayskiy

We show that the evolution of magnetic fields in a primordial plasma, filled with standard model particles at temperatures T greater than or similar to 10 MeV, is strongly affected by the chiral anomaly-an effect previously neglected. Although reactions, e ...

2012

Long-Range Magnetic Fields in the Ground State of the Standard Model Plasma

Mikhail Chapochnikov, Alexey Boyarsky, Oleg Ruchayskiy

In thermal equilibrium the ground state of the plasma of Standard Model particles is determined by temperature and exactly conserved combinations of baryon and lepton numbers. We show that at nonzero values of the global charges a translation invariant and ...

American Physical Society2012

The haloes of bright satellite galaxies in a warm dark matter universe

Alexey Boyarsky, Oleg Ruchayskiy, Jie Wang

High-resolution N-body simulations of galactic cold dark matter haloes indicate that we should expect to find a few satellite galaxies around the Milky Way whose haloes have a maximum circular velocity in excess of 40 km s-1. Yet, with the exception of the ...

Blackwell Publishing Ltd, Oxford2012

Next decade of sterile neutrino studies

Alexey Boyarsky, Oleg Ruchayskiy

We review the status of sterile neutrino dark matter and discuss astrophysical and cosmological bounds on its properties as well as future prospects for its experimental searches. We argue that if sterile neutrinos are the dominant fraction of dark matter, ...

2012

Tag Recommendation for Large-Scale Ontology-Based Information Systems

Philippe Cudré-Mauroux, Karl Aberer, Alexey Boyarsky, Oleg Ruchayskiy, Roman Prokofyev

We tackle the problem of improving the relevance of automatically selected tags in large-scale ontology-based information systems. Contrary to traditional settings where tags can be chosen arbitrarily, we focus on the problem of recommending tags (e.g., co ...

Springer2012

A comment on the emission from the Galactic Center as seen by the Fermi telescope

Alexey Boyarsky, Oleg Ruchayskiy

In the recent paper of Hooper and Goodenough (2010) [10] it was reported that gamma-ray emission from the Galactic Center region contains an excess compared to the contributions from the large-scale diffuse emission and known point sources. This excess was ...

2011

Proposed new probe of modified gravity

Alexey Boyarsky, Oleg Ruchayskiy

We suggest a new efficient way to constrain a certain class of large scale modifications of gravity. We show that the scale-free relation between density and size of dark matter halos, predicted within the ACDM model with Newtonian gravity, gets modified i ...

2011

Searching for dark matter in X-rays: how to check the dark matter origin of a spectral feature

Alexey Boyarsky, Oleg Ruchayskiy

A signal from decaying dark matter (DM) can be unambiguously distinguished from spectral features of astrophysical or instrumental origin by studying its spatial distribution. We demonstrate this approach by examining the recent claim of Loewenstein and Ku ...

Blackwell Publishing Ltd, Oxford2010

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