Unravelling the Mysteries of the Leo Ring: An Absorption Line Study of an Unusual Gas Cloud

Since the 1980's discovery of the large (2x10^9 Msun) intergalactic cloud known as the Leo Ring, this object has been the center of a lively debate about its origin. Determining the origin of this object is still important as we develop a deeper understanding of the accretion and feedback processes that shape galaxy evolution. We present HST/COS observations of three sightlines near the Ring, two of which penetrate the high column density neutral hydrogen gas visible in 21 cm observations of the object. These observations provide the first direct measurement of the metallicity of the gas in the Ring, an important clue to its origins. Our best estimate of the metallicity of the ring is ~10% Zsun, higher than expected for primordial gas but lower than expected from an interaction. We discuss possible modifications to the interaction and primordial gas scenarios that would be consistent with this metallicity measurement.Comment: 11 pages, 7 figures, accepted Ap

Sex and the Cinema: What American Pie Teaches the Young

This paper focuses upon the wildly successful blockbuster American Pie teenpics, especially American Pie 3 – the Wedding. I argue that these films, which are sited so securely within the visual and pedagogical machinery of Hollywood culture, are specifically designed to appeal to teenage male audiences, and to provide lessons in sex and romance. Movies like this are especially important as they are experienced by far more teenagers than, for example, instructional films or other classroom materials; indeed, as Henry Giroux has observed, "teens and youth learn how to define themselves outside of the traditional sites of instruction, such as the home and the school… Learning in the postmodern age is located elsewhere – in popular spheres that shape their identities, through forms of knowledge and desires that appear absent from what is taught in schools" (Giroux, 1997, p.49). In this paper I discuss whether the American Pie series is actually a "new age" effort which, via insubordinate performances of gender, contests the hegemonic field of signification which regulates the production of sex, gender and desire, or whether it is more accurately described as a retrogressive hetero-conservative opus with a veneer of sexual radicalism. In short, I intend to probe whether this filmic vector for sex education is all about the shaping of responsible, caring, vulnerable men, or is it guiding them to become just like their heterosexual, middle-class fathers? And whether, despite its riotous and raunchy advertising, American Pie really dishes up something spicy or something terribly wholesome instead

Beyond ‘ignorance’: using the cultural stereotypes of Americans studying in the UK as a resource for learning and teaching about British culture

A course introducing British culture is a standard component of many study abroad programmes running in this country that are aimed at international students who will be spending a limited amount of time in the United Kingdom. However, it is not often acknowledged that such students possess a range of strong pre-conceptions about British culture and society prior to their arrival. Conventional teaching strategies assume student ignorance of the subject. However, an alternative approach which makes us of pre-arrival stereotypes can be more productive in terms of engaging students in active processes of comparative analysis of their new and existing knowledge. A case study of American student stereotypes of the British monarchy is presented and it is suggested that these can be used as the basis for refining student understanding of cultural politics in the United Kingdom. International students, therefore, should not be treated as being culturally ignorant of Britain in the sense of having no knowledge or opinions at all. Rather, it should be understood that they possess a culturally mediated state of subjectivity which I refer to as ‘ignorance’ and that this can become a valuable resource for teaching and learning

Mutual Fund Management and Fund Performance

This study examines management characteristics, including education and experience, as determinants of mutual fund performance.  Managers with graduate degrees did not perform differently from managers without graduate degrees.  However, graduates of top 20 MBA programs outperformed MBAs from business schools not on the top 50 Wall Street Journal list.  Manager’s tenure was positively related to performance

Witten's conjecture and Property P

Let K be a non-trivial knot in the 3-sphere and let Y be the 3-manifold obtained by surgery on K with surgery-coefficient 1. Using tools from gauge theory and symplectic topology, it is shown that the fundamental group of Y admits a non-trivial homomorphism to the group SO(3). In particular, Y cannot be a homotopy-sphere.Comment: Published by Geometry and Topology at http://www.maths.warwick.ac.uk/gt/GTVol8/paper7.abs.html Version 5: links correcte

What can be measured asymptotically?

We consider asymptotic observables in quantum field theories in which the S-matrix makes sense. We argue that in addition to scattering amplitudes, a whole compendium of inclusive observables exists where the time-ordering is relaxed. These include expectation values of electromagnetic or gravitational radiation fields as well as out-of-time-order amplitudes. We explain how to calculate them in two ways: by relating them to amplitudes and products of amplitudes, and by using a generalization of the LSZ reduction formula. As an application, we discuss one-loop master integrals contributing to gravitational radiation in the post-Minkowski expansion, emphasizing the role of classical cut contributions and highlighting the different infrared physics of in-in observables.Comment: 67 pages, typos correcte

Numerical study of fixed Oscillating Water Column with RANS-type two-phase CFD model

publisher: Elsevier articletitle: Numerical study of fixed Oscillating Water Column with RANS-type two-phase CFD model journaltitle: Renewable Energy articlelink: http://dx.doi.org/10.1016/j.renene.2016.10.044 content_type: article copyright: © 2016 Elsevier Ltd. All rights reserved

Crossing beyond scattering amplitudes

We find that different asymptotic measurements in quantum field theory can be related to one another through new versions of crossing symmetry. Assuming analyticity, we conjecture generalized crossing relations for multi-particle processes and the corresponding paths of analytic continuation. We prove them to all multiplicity at tree-level in quantum field theory and string theory. We illustrate how to practically perform analytic continuations on loop-level examples using different methods, including unitarity cuts and differential equations. We study the extent to which anomalous thresholds away from the usual physical region can cause an analytic obstruction to crossing when massless particles are involved. In an appendix, we review and streamline historical proofs of four-particle crossing symmetry in gapped theories.Comment: 108 page