Initial data for black hole-neutron star binaries, with rotating stars

The coalescence of a neutron star with a black hole is a primary science target of ground-based gravitational wave detectors. Constraining or measuring the neutron star spin directly from gravitational wave observations requires knowledge of the dependence of the emission properties of these systems on the neutron star spin. This paper lays foundations for this task, by developing a numerical method to construct initial data for black hole--neutron star binaries with arbitrary spin on the neutron star. We demonstrate the robustness of the code by constructing initial-data sets in large regions of the parameter space. In addition to varying the neutron star spin-magnitude and spin-direction, we also explore neutron star compactness, mass-ratio, black hole spin, and black hole spin-direction. Specifically, we are able to construct initial data sets with neutron stars spinning near centrifugal break-up, and with black hole spins as large as $S_{\rm BH}/M_{\rm BH}^2=0.99$.Comment: 25 pages, 12 figure

Binary Neutron Stars with Arbitrary Spins in Numerical Relativity

We present a code to construct initial data for binary neutron star systems in which the stars are rotating. Our code, based on a formalism developed by Tichy, allows for arbitrary rotation axes of the neutron stars and is able to achieve rotation rates near rotational breakup. We compute the neutron star angular momentum through quasi-local angular momentum integrals. When constructing irrotational binary neutron stars, we find a very small residual dimensionless spin of $\sim 2\times 10^{-4}$. Evolutions of rotating neutron star binaries show that the magnitude of the stars' angular momentum is conserved, and that the spin- and orbit-precession of the stars is well described by post-Newtonian approximation. We demonstrate that orbital eccentricity of the binary neutron stars can be controlled to $\sim 0.1\%$. The neutron stars show quasi-normal mode oscillations at an amplitude which increases with the rotation rate of the stars.Comment: 20 pages, 22 figure

Comparative Energy Dependence of Proton and Pion Degradation in Diamond

A comparative theoretical study of the damages produced by protons and pions, in the energy range 50 MeV - 50 GeV, in diamond, is presented. The concentration of primary defects (CPD) induced by hadron irradiation is used to describe material degradation. The CPD has very different behaviours for protons and pions: the proton degradation is important at low energies and is higher than the pion one in the whole energy range investigated, with the exception of the Delta33 resonance region, where a large maximum of the degradation exists for pions. In comparison with silicon, the most investigated and the most studied material for detectors, diamond theoretically proves to be one order of magnitude more resistant, both to proton and pion irradiation.Comment: 7 pages, 5 figure

Longitudinal muon spin relaxation in high purity aluminum and silver

The time dependence of muon spin relaxation has been measured in high purity aluminum and silver samples in a longitudinal 2 T magnetic field at room temperature, using time-differential \musr. For times greater than 10 ns, the shape fits well to a single exponential with relaxation rates of \lambda_{\textrm{Al}} = 1.3 \pm 0.2\,(\textrm{stat.}) \pm 0.3\,(\textrm{syst.})\,\pms and \lambda_{\textrm{Ag}} = 1.0 \pm 0.2\,(\textrm{stat.}) \pm 0.2\,(\textrm{syst.})\,\pms

Diamond degradation in hadron fields

The energy dependence of the concentration of primary displacements induced by protons and pions in diamond has been calculated in the energy range 50 MeV - 50 GeV, in the frame of the Lindhard theory. The concentrations of primary displacements induced by protons and pions have completely different energy dependencies: the proton degradation is very important at low energies, and is higher than the pion one in the whole energy range investigated, with the exception of the delta33 resonance region. Diamond has been found, theoretically, to be one order of magnitude more resistant to proton and pion irradiation in respect to silicon.Comment: 7 pages, 3 figure

Violence in self-determination conflicts : exploring the zone of exception in international law

The role played by the right of peoples to self-determination in international law after decolonization demonstrates that violence is to be found not only outside the law or at its foundations, in the law-establishing act, but also within zones created by the law itself. What is so striking about this right that it does not correspond to any concrete entitlement that is invokable or enforceable within international law. It corresponds to a proper abyss: a politico-moral slogan that only when fought with and through violence materializes itself as a right that has been exercised. In this sense, the right to self-determination exists only once exercised and thus covers up the exceptional zone of violence. During the conflict itself, it is nothing but a claim in the name of which the secessionists raise their arms. Through the right to self-determination international law attempts to cordon off and obfuscate something that it cannot properly grasp: the sphere of factual violence used to create a state through secession. This right is not created by violence, but exercised through its use. In this sense, the right to self-determination neither bans violence nor is established by it: it exists only as a vague principle until violence brings it to the proper status of a right. Unlike typical rights, the right to self-determination does not construct a simple tri-partite syllogism: (1) general norm, (2) factual situation and (3) concretization of a general norm. The form this right has before application is incommensurate with what it is transformed into after this act. Violence mediates between the principle and the right, allowing the latter to constitute itself retroactively as a seemingly exercisable norm

The Freedom of Lights: Edmond Jabès and Jewish Philosophy of Modernity

Edmond Jabès was one of the most intriguing Jewish thinkers of the 20th century – a poet for the public and a Kabbalist for those who read his work more closely. This book turns his writings into a ground-breaking philosophical achievement: thinking which is manifestly indebted to the Kabbalah, but in the post-religious and post-Shoah world. Loss, exile, negativity, God’s absence, writing and Jewishness are the main signposts of the negative ontology which this book offers as an interpretation of Jabès’ work. On the basis of it, the book examines the nature of the miraculous encounter between Judaism and philosophy which occurred in the 20th century. Modern Jewish philosophy is a re-constructed tradition which adapts the intellectual and spiritual legacy of Judaism to answer purely modern questions

Ernst Bloch as a non-simultaneous Jewish Marxist

The paper attempts to reassess the fundamentally paradoxical position of Ernst Bloch in 20th century philosophy in the light of the Marranic condition. Indebted, among others, to Jewish heritage and Christian tradition, Bloch considered himself primarily a Marxist. Bloch's uniqueness consists in the stunning equiponderance of the currents he drew from. Contrary to a classic model of modern Jewish philosophy, inaugurated by Hermann Cohen, Bloch's thinking does not allow of easy juxtaposition of "sources" with languages into which they were translated. In this sense, Bloch cannot be easily compared to Franz Rosenzweig, Emmanuel Levinas or even Walter Benjamin (although he bore some striking similarities with the latter). His position at least partly stems from a specific form of directness with which he often used these languages, composing his philosophy in quite an anachronist manner. For this reason his thinking - in itself "die Gleichzeitigkeit des Ungleichzeitigen", as one of his key concepts theorises - is a very modern, internally incoherent space of cross-fertilising inspirations. The paper demonstrates two levels on which Bloch's indebtedness to Judaism might be analysed and then re-assesses his Marxist affiliations as a kind of modern faith which, in a specifically Marranic manner, seals the simultaneity of the non-simultaneous

Study of Two-Step Mechanisms in Pion Absorption on 6Li, 12C via Deuteron Emission

The (pi+,pd), and (pi+,dd) reactions were investigated with pions of 100 and 165 MeV kinetic energy on 6Li and 12C targets. In comparison with previously published (pi+,pp) data on the same targets and at the same beam energies, kinematic regions were identified in which the neutron pickup process n+p->d dominated the observed deuteron yield. The importance of this mechanism increases with energy, contributing half of the observed cross section at 165 MeV. The contribution of direct quasi-triton absorption is significant only at 100 MeV.Comment: 23 pages, 12 figure