Neutrino flux predictions for known Galactic microquasars

It has been proposed recently that Galactic microquasars may be prodigious emitters of TeV neutrinos that can be detected by upcoming km^2 neutrino telescopes. In this paper we consider a sample of identified microquasars and microquasar candiates, for which available data enables rough determination of the jet parameters. By employing the parameters inferred from radio observations of various jet ejection events, we determine the neutrino fluxes that should have been produced during these events by photopion production in the jet. Despite the large uncertainties in our analysis, we demonstrate that in several of the sources considered, the neutrino flux at Earth, produced in events similar to those observed, would exceed the detection threshold of a km^2 neutrino detector. The class of microquasars may contain also sources with bulk Lorentz factors larger than those characteristic of the sample considered here, directed along our line of sight. Such sources, which may be very difficult to resolve at radio wavelengths and hence may be difficult to identify as microqusar candidates, may emit neutrinos with fluxes significantly larger than typically obtained in the present analysis. These sources may eventually be identified through their neutrino and gamma-ray emission.Comment: 17 pages. Submitted to Ap

Independent Media in a Small Town 2011-2012

This study is part of a larger project on the role of local (independent) press in the development of civil society in small cities. In 2007, a series of research was done in the towns of Dobryanka, Tchaikovsky, Zheleznogorsk, Serpukhov, Kachkanar and Kudymkar.As part of this first phase of our research project, we studied factors and functional conditions that drive the need for the existence of independent media and ensure their independence. Field work was mainly carried out in 2011and completed at the end of 2012. In 2011, the survey covered the towns of Berdsk, Novoaltaisk, Sarapul, Serov, Dubna and Zhukovsky. In 2012, further interviews were conducted in Zhukovsky with representatives of different social groups and the editorial staff of the newspaper "Zhukovskiye news" .For several reasons, this report is completed at the end of 2012. This time was full of political events and changes in the political climate of the country. Therefore, part of the observations of this work have lost their political relevance, but retain sociological interest

Entanglement, measurement, and conditional evolution of the Kondo singlet interacting with a mesoscopic detector

We investigate various aspects of the Kondo singlet in a quantum dot (QD) electrostatically coupled to a mesoscopic detector. The two subsystems are represented by an entangled state between the Kondo singlet and the charge-dependent detector state. We show that the phase-coherence of the Kondo singlet is destroyed in a way that is sensitive to the charge-state information restored both in the magnitude and in the phase of the scattering coefficients of the detector. We also introduce the notion of the `conditional evolution' of the Kondo singlet under projective measurement on the detector. Our study reveals that the state of the composite system is disentangled upon this measurement. The Kondo singlet evolves into a particular state with a fixed number of electrons in the quantum dot. Its relaxation time is shown to be sensitive only to the QD-charge dependence of the transmission probability in the detector, which implies that the phase information is erased in this conditional evolution process. We discuss implications of our observations in view of the possible experimental realization.Comment: Focus issue on "Interference in Mesoscopic Systems" of New J. Phy

Zero-energy states in graphene quantum dots and rings

We present exact analytical zero-energy solutions for a class of smooth decaying potentials, showing that the full confinement of charge carriers in electrostatic potentials in graphene quantum dots and rings is indeed possible without recourse to magnetic fields. These exact solutions allow us to draw conclusions on the general requirements for the potential to support fully confined states, including a critical value of the potential strength and spatial extent.Comment: 8 pages, 3 figures, references added, typos corrected, discussion section expande

A Mesoscopic Quantum Eraser

Motivated by a recent experiment by Buks et al. [Nature 391, 871 (1998)] we consider electron transport through an Aharonov-Bohm interferometer with a quantum dot in one of its arms. The quantum dot is coupled to a quantum system with a finite number of states acting as a which-path detector. The Aharonov-Bohm interference is calculated using a two-particle scattering approach for the joint transitions in detector and quantum dot. Tracing over the detector yields dephasing and a reduction of the interference amplitude. We show that the interference can be restored by a suitable measurement on the detector and propose a mesoscopic quantum eraser based on this principle.Comment: 7 pages, 2 figures, to appear in Europhys. Lett., uses EuroPhys.sty and EuroMacro.tex (included

Probing Micro-quasars with TeV Neutrinos

The jets associated with Galactic micro-quasars are believed to be ejected by accreting stellar mass black-holes or neutron stars. We show that if the energy content of the jets in the transient sources is dominated by electron-proton plasma, then a several hour outburst of 1--100 TeV neutrinos produced by photo- meson interactions should precede the radio flares associated with major ejection events. Several neutrinos may be detected during a single outburst by a 1km^2 detector, thereby providing a powerful probe of micro-quasars jet physics.Comment: Accepted to PRL. More detailed discussion of particle acceleratio

Introduction: Reciprocals and semantic typology

Reciprocity lies at the heart of social cognition, and with it so does the encoding of reciprocity in language via reciprocal constructions. Despite the prominence of strong universal claims about the semantics of reciprocal constructions, there is considerable descriptive literature on the semantics of reciprocals that seems to indicate variable coding and subtle cross-linguistic differences in meaning of reciprocals, both of which would make it impossible to formulate a single, essentialising definition of reciprocal semantics. These problems make it vital for studies in the semantic typology of reciprocals to employ methodologies that allow the relevant categories to emerge objectively from cross-linguistic comparison of standardised stimulus materials. We situate the rationale for the 20-language study that forms the basis for this book within this empirical approach to semantic typology, and summarise some of the findings