Universal properties of Dark Matter halos (2009)
Boyarsky, Alexey, Neronov, Andrey, Ruchayskiy, Oleg, Tkachev, Igor
We discuss the universal relation between density and size of Dark Matter halos.This relation was recently shown to hold on a wide range of scales, from dwarf galaxies to galaxy clusters, both in...
New evidence for dark matter (2009)
Boyarsky, Alexey, Ruchayskiy, Oleg, Iakubovskyi, Dmytro, Maccio', Andrea V., Malyshev, Denys
We present a new universal relation, satisfied by matter distributions at all observed scales, and show its amazingly good and detailed agreement with the predictions of the most up-to-date pure dark...
Effective field theories for the $\nu = 5/2$ edge (2009)
Boyarsky, Alexey, Cheianov, Vadim, Fröhlich, Jürg
We present a list of possible effective theories which may describe a QHE edge at filling fraction $\nu =5/2$. We show that there exist several abelian and non-abelian effective theories (apart from...
Anomaly driven signatures of new invisible physics at the Large Hadron Collider (2009)
Antoniadis, Ignatios, Boyarsky, Alexey, Espahbodi, Sam, Ruchayskiy, Oleg, Wells, James D.
Many extensions of the Standard Model (SM) predict new neutral vector bosons at energies accessible by the Large Hadron Collider (LHC). We study an extension of the SM with new chiral fermions...
The role of sterile neutrinos in cosmology and astrophysics (2008)
Boyarsky, Alexey, Ruchayskiy, Oleg, Shaposhnikov, Mikhail
We present a comprehensive overview of an extension of the Standard Model by three right-handed (sterile) neutrinos with masses below the electroweak scale (the Neutrino Minimal Standard Model,...
Mach-Zehnder interferometry of fractional quantum Hall edge states (2008)
Levkivskyi, Ivan P., Boyarsky, Alexey, Froehlich, Juerg, Sukhorukov, Eugene V.
We propose direct experimental tests of the effective models of fractional quantum Hall edge states. We first recall a classification of effective models based on the requirement of anomaly...
Realistic sterile neutrino dark matter with keV mass does not contradict cosmological bounds (2008)
Boyarsky, Alexey, Lesgourgues, Julien, Ruchayskiy, Oleg, Viel, Matteo
Previous fits of sterile neutrino dark matter models to cosmological data assumed a peculiar production mechanism, which is not representative of the best-motivated particle physics models given...
Realistic sterile neutrino dark matter with keV mass does not contradict cosmological bounds (2008)
Boyarsky, Alexey, Lesgourgues, Julien, Ruchayskiy, Oleg, Viel, Matteo
Previous fits of sterile neutrino dark matter models to cosmological data assumed a peculiar production mechanism, which is not representative of the best-motivated particle physics models given...
Lyman-$\alpha$ constraints on warm and on warm-plus-cold dark matter models (2008)
Boyarsky, Alexey, Lesgourgues, Julien, Ruchayskiy, Oleg, Viel, Matteo
We revisit Lyman-alpha bounds on the dark matter mass in Lambda Warm Dark Matter (Lambda-WDM) models, and derive new bounds in the case of mixed Cold plus Warm models (Lambda-CWDM), using a set up...
Lyman-alpha constraints on warm and on warm-plus-cold dark matter models (2008)
Boyarsky, Alexey, Lesgourgues, Julien, Ruchayskiy, Oleg, Viel, Matteo
We revisit Lyman-alpha bounds on the dark matter mass in Lambda Warm Dark Matter (Lambda-WDM) models, and derive new bounds in the case of mixed Cold plus Warm models (Lambda-CWDM), using a set up...
Bounds on Light Dark Matter (2008)
Boyarsky, Alexey, Ruchayskiy, Oleg
In this talk we review existing cosmological and astrophysical bounds on light (with the mass in keV - MeV range) and super-weakly interacting dark matter candidates. A particular attention is paid...
A lower bound on the mass of Dark Matter particles (2008)
Boyarsky, Alexey, Ruchayskiy, Oleg, Iakubovskyi, Dmytro
We discuss the bounds on the mass of Dark Matter (DM) particles, coming from the analysis of DM phase-space distribution in dwarf spheroidal galaxies (dSphs). After reviewing the existing approaches,...
Constraining DM properties with SPI (2007)
Boyarsky, Alexey, Malyshev, Denys, Neronov, Andrey, Ruchayskiy, Oleg
We search for a spectral line produced by a dark matter (DM) particle with the mass in the range 40 keV < M_DM < 14 MeV, decaying in the DM halo of the Milky Way, using a high-resolution spectrometer...
Constraining DM properties with SPI (2007)
Boyarsky, Alexey, Malyshev, Denys, Neronov, Andrey, Ruchayskiy, Oleg
Using the high-resolution spectrometer SPI on board the International Gamma-Ray Astrophysics Laboratory (INTEGRAL), we search for a spectral line produced by a dark matter(DM) particle with a mass in...
Constraints on decaying Dark Matter from XMM-Newton observations of M31 (2007)
Boyarsky, Alexey, Iakubovskyi, Dmytro, Ruchayskiy, Oleg, Savchenko, Vladimir
We derive constraints on parameters of the radiatively decaying Dark Matter (DM) particles, using XMM-Newton EPIC spectra of the Andromeda galaxy (M31). Using the observations of the outer (5'-13')...
Constraints on decaying Dark Matter from XMM-Newton observations of M31 (2007)
Boyarsky, Alexey, Iakubovskyi, Dmytro, Ruchayskiy, Oleg, Savchenko, Vladimir
We derive constraints on parameters of the radiatively decaying Dark Matter (DM) particles, using XMM-Newton EPIC spectra of the Andromeda galaxy (M31). Using the observations of the outer (5'-13')...
Anomaly induced effects in a magnetic field (2007)
Antoniadis, Ignatios, Boyarsky, Alexey, Ruchayskiy, Oleg
We consider a modification of electrodynamics by an additional light massive vector field, interacting with the photon via Chern-Simons-like coupling. This theory predicts observable effects for the...
Search for the light dark matter with an X-ray spectrometer (2006)
Boyarsky, Alexey, Herder, Jan Willem Den, Neronov, Andrey, Ruchayskiy, Oleg
Sterile neutrinos with the mass in the keV range are interesting warm dark matter (WDM) candidates. The restrictions on their parameters (mass and mixing angle) obtained by current X-ray missions...
Boyarsky, Alexey, Ruchayskiy, Oleg, Markevitch, Maxim
We derived constraints on parameters of a radiatively decaying warm dark matter particle, e.g., the mass and mixing angle for a sterile neutrino, using Chandra X-ray spectra of a galaxy cluster...
Boyarsky, Alexey, Nevalainen, Jukka, Ruchayskiy, Oleg
We improve the earlier restrictions on parameters of the dark matter (DM) in the form of a sterile neutrino. The results were obtained from non-observing the DM decay line in the X-ray spectrum of...
Boyarsky, Alexey, Neronov, Andrey, Ruchayskiy, Oleg, Shaposhnikov, Mikhail
We find restrictions on the mass and mixing angle of the dark matter sterile neutrinos using X-ray observations of Coma and Virgo galaxy clusters.
Anomalies as a signature of extra dimensions (2005)
Boyarsky, Alexey, Ruchayskiy, Oleg, Shaposhnikov, Mikhail
The anomaly cancellation condition of the Standard Model may be unnatural in theories with extra dimensions as an anomaly of a low-energy 4-dimensional theory can be canceled by an inflow from a...
Observational manifestations of anomaly inflow (2005)
Boyarsky, Alexey, Ruchayskiy, Oleg, Shaposhnikov, Mikhail
In theories with chiral couplings, one of the important consistency requirements is that of the cancellation of a gauge anomaly. In particular, this is one of the conditions imposed on the...
Fermions in the harmonic potential and string theory (2004)
Boyarsky, Alexey, Cheianov, Vadim V., Ruchayskiy, Oleg
We explicitly derive collective field theory description for the system of fermions in the harmonic potential. This field theory appears to be a coupled system of free scalar and (modified) Liouville...
Classical and Quantum Branes in c=1 String Theory and Quantum Hall Effect (2003)
Boyarsky, Alexey, Kulik, Bogdan, Ruchayskiy, Oleg
Interpretation of D1 and D0-branes in 1+1 string theory as classical and quantum eigen-values in dual c=1 Matrix Quantum Mechanics (MQM) was recently suggested. MQM is known to be equivalent to a...
String field theory vertices, integrability and boundary states (2003)
Boyarsky,Alexey, Kulik,Bogdan, Ruchayskiy,Oleg
We study Neumann coefficients of the various vertices in theWitten’s open string field theory (SFT). We show that they are not independent, but satisfy an infinite set of algebraic relations. These...
Classical and Quantum Branes in c=1 String Theory and Quantum Hall Effect (2003)
Boyarsky,Alexey, Kulik,Bogdan, Ruchayskiy,Oleg
Interpretation of D1 and D0-branes in 1+1 string theory as classical and quantum eigen-values in dual c=1 Matrix Quantum Mechanics (MQM) was recently suggested. MQM is known to be equivalent to a...
String field theory vertices, integrability and boundary states (2003)
Boyarsky, Alexey, Kulik, Bogdan, Ruchayskiy, Oleg
We study Neumann coefficients of the various vertices in theWitten’s open string field theory (SFT). We show that they are not independent, but satisfy an infinite set of algebraic relations. These...
Classical and Quantum Branes in c=1 String Theory and Quantum Hall Effect (2003)
Boyarsky, Alexey, Kulik, Bogdan, Ruchayskiy, Oleg
Interpretation of D1 and D0-branes in 1+1 string theory as classical and quantum eigen-values in dual c=1 Matrix Quantum Mechanics (MQM) was recently suggested. MQM is known to be equivalent to a...
Integrability in SFT and new representation of KP tau-function (2002)
Boyarsky, Alexey, Ruchayskiy, Oleg
We are investigating the properties of vacuum and boundary states in the CFT of free bosons under the conformal transformation. We show that transformed vacuum (boundary state) is given in terms of...
A Toy Model of the M5-brane: Anomalies of Monopole Strings in Five Dimensions (2002)
Boyarsky, Alexey, Harvey, Jeffrey A., Ruchayskiy, Oleg
We study a five-dimensional field theory which contains a monopole (string) solution with chiral fermion zero modes. This monostring solution is a close analog of the fivebrane solution of M-theory....