Cosmology with Hypervelocity Stars

In the standard cosmological model, the merger remnant of the Milky Way and Andromeda (Milkomeda) will be the only galaxy remaining within our event horizon once the Universe has aged by another factor of ten, ~10^{11} years after the Big Bang. After that time, the only extragalactic sources of light in the observable cosmic volume will be hypervelocity stars being ejected continuously from Milkomeda. Spectroscopic detection of the velocity-distance relation or the evolution in the Doppler shifts of these stars will allow a precise measurement of the vacuum mass density as well as the local matter distribution. Already in the near future, the next generation of large telescopes will allow photometric detection of individual stars out to the edge of the Local Group, and may target the ~10^{5+-1} hypervelocity stars that originated in it as cosmological tracers.Comment: 4 pages, 2 figures, accepted for publication in the Journal of Cosmology and Astroparticle Physics (JCAP, 2011

Theology in Public Reason and Legal Discourse: A Case for the Preferential Option for the Poor

There is a strange disconnect between the formal understanding of the separation of religion from government in the United States and the almost ubiquitous use of religious language in political discourse, not to mention the web of complicated religious motivations that sit on or just below the surface of policy debates. This paper presents an argument for the relevance of the principle of the preferential option for the poor from Catholic social thought in public reason and legal discourse in order to explore the possible advantages of making the veil between religion and the secular state more permeable. As a case study, it proposes dialogue between Catholicism and complementary secular thought, including standpoint theory, outsider methodology, and law and economics to explore possibilities for more effectively ensuring justice for the poor and marginalized

The Highest Energy Neutrinos

Measurements of the arrival directions of cosmic rays have not revealed their sources. High energy neutrino telescopes attempt to resolve the problem by detecting neutrinos whose directions are not scrambled by magnetic fields. The key issue is whether the neutrino flux produced in cosmic ray accelerators is detectable. It is believed that the answer is affirmative, both for the galactic and extragalactic sources, provided the detector has kilometer-scale dimensions. We revisit the case for kilometer-scale neutrino detectors in a model-independent way by focussing on the energetics of the sources. The real breakthrough though has not been on the theory but on the technology front: the considerable technical hurdles to build such detectors have been overcome. Where extragalactic cosmic rays are concerned an alternative method to probe the accelerators consists in studying the arrival directions of neutrinos produced in interactions with the microwave background near the source, i.e. within a GZK radius. Their flux is calculable within large ambiguities but, in any case, low. It is therefore likely that detectors that are larger yet by several orders of magnitudes are required. These exploit novel techniques, such as detecting the secondary radiation at radio wavelengths emitted by neutrino induced showers.Comment: 16 pages, pdflatex, 7 jpg figures, ICRC style files included. Highlight talk presented at the 30th International Cosmic Ray Conference, Merida, Mexico, 200

Israel, Latin America and the United States: A Peripheral-Realist Perspective

This document is the paper-format version of the keynote address delivered by its author on August 2, 2009, to the opening session of the Latin American section (AMILAT) of the 15th World Congress of Jewish Studies, at the Hebrew University of Jerusalem. It attempts to understand the long-term shift towards the worse of Israeli-Latin American relations, which started with an almost unqualified support for the establishment of the State of Israel on the side of both Latin American right-wing governments and left-wing parties and popular organizations, but have been deteriorating ever since. It suggests that this involution can be largely explained in terms of at least four intervening variables: Israel's vulnerability, its special relationship with the United States after 1967, Latin American social structure, and the class identity of the leadership of the Latin American Jewry. It argues that overlooking the peripheral character of Israel in the interstate system has led to distortions in the understanding of Israeli-Latin American relations

Superposition of Weyl solutions: The equilibrium forces

Solutions to the Einstein equation that represent the superposition of static isolated bodies with axially symmetry are presented. The equations nonlinearity yields singular structures (strut and membranes) to equilibrate the bodies. The force on the strut like singularities is computed for a variety of situations. The superposition of a ring and a particle is studied in some detailComment: 31 pages, 7 figures, psbox macro. Submitted to Classical and Quantum Gravit