2,425 research outputs found

    Explicit solution of the linearized Einstein equations in TT gauge for all multipoles

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    We write out the explicit form of the metric for a linearized gravitational wave in the transverse-traceless gauge for any multipole, thus generalizing the well-known quadrupole solution of Teukolsky. The solution is derived using the generalized Regge-Wheeler-Zerilli formalism developed by Sarbach and Tiglio.Comment: 9 pages. Minor corrections, updated references. Final version to appear in Class. Quantum Gra

    Deliberative representation in parliament

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    This research sets out clarifying theoretically the relations with two democratically relevant concepts: political representation and deliberation. It does so by developing the idea of ‘deliberative representation’ and studying it empirically in a parliamentary context. Recent scholarship of representation, namely the constructivist turn, sees the concept of representation as dynamic and fluid. As such, this paradigm shift looks past the electoral notion that highlights the premise of interests and preferences. Scholarship on deliberation is similarly revising its focus. This research draws especially from the systemic approach to deliberation. It implies that loosening traditional normative criteria will advance the study of deliberation in politically charged settings such as legislatures. Both strands of theories are gradually assuming context and function sensitive perspectives that are merged in my reading of deliberative representation. The under-theorised link between representation and deliberation has resulted in shortage of empirical accounts of where representatives operate in. The research is motivated by a simple question: what do representatives actually do when they represent? Finding answers to this question helps in understanding what drives deliberation in parliaments. The proposed framework of deliberative representation allows a more nuanced outlook on representative activities and practices. Consequently, this refined perspective allows addressing and re-assessing some prevailing assumptions of political science about the strategic and adversarial incentives and orientations of elected representatives. In this research, the dynamics of deliberative representation are studied in and illustrated through a particular legislature, the Parliament of Finland. For this purpose, 60 Finnish Members of Parliament (and 5 parliamentary committee chairs) were interviewed over the period of 2008–2016. The research illustrates that although institutional and procedural settings of legislature incentivize representative practices, thus inducing deliberation in various ways, the contextual and functional interplay argued by deliberative representation adds to the analysis in novel ways. Three dominant contexts of representation are identified: the affirmative, operative and performative context. Each discussed context specifies how the functions of representation are established and carried out. Also, features relating to the deliberative process are explored. Finally, three deliberative modes are detected in the contexts of representation: what I call expressive-deliberative, strategic-deliberative and expressive-partisan deliberative mode. The novelty of this research lies in its aspiration to use the language of political theory more closely in conducting empirical inquiry. While doing that, it has also contributed to the scholarship on representative practices in parliaments. Finally, the research suggests that the contexts of representation are generally recognizable, and therefore they may find applications outside the parliamentary setting.Tutkimuksen tarkoituksena on tarkastella parlamenttia edustamisen ja deliberaation eli harkitsevan ja punnitsevan puheen paikkana. Tutkimuksen kysymyksenasettelu on lĂ€htökohdiltaan teoreettinen. Se sijoittuu politiikan teorian, erityisesti deliberatiivisen demokratiateorian ja poliittista edustamista kĂ€sittelevien keskusteluiden lĂ€pileikkauskohtaan. Johtuen siitĂ€, ettĂ€ edustamisen ja deliberaation vĂ€linen suhde on jokseenkin aliteoretisoitu, on myös tĂ€stĂ€ nĂ€kökulmasta tehtyjen, edustajien toiminnalliseen työympĂ€ristöön sijoittuvien empiiristen tutkimusten mÀÀrĂ€ vĂ€hĂ€inen. TĂ€ten tutkimuksella on myös toinen tavoite: tuoda parlamentti ja siellĂ€ tapahtuva edustustoiminta empiirisen tutkimuksen kohteeksi. Tutkimuksen aineiston muodostaa 60 suomalaisen kansanedustajan (ja viiden valiokuntaneuvoksen) puolistrukturoidut tutkimushaastattelut, jotka on kerĂ€tty aikavĂ€lillĂ€ 2008–2016. Tutkimus lĂ€htee liikkeelle hyvin yksinkertaisesta ajatuksesta: mitĂ€ edustajat oikeastaan kĂ€ytĂ€nnössĂ€ tekevĂ€t kun he edustavat? TĂ€ssĂ€ työssĂ€ hahmotellaan analyyttinen työkalu, deliberatiivinen edustaminen, jota tarkastellaan tutkimuksessa mÀÀriteltyjen kolmen edustamisen kontekstin kautta. NiissĂ€ edustamisella ja deliberaatiolla on omat tarkoituksensa ja tavoitteensa. Kansanedustajat tunnistavat nĂ€mĂ€ muutokset deliberaation kĂ€ytössĂ€ ja hyödyntĂ€misessĂ€, kun kyseessĂ€ on esimerkiksi eduskuntaryhmĂ€n sisĂ€inen toiminta, valiokunnan kokous tai istuntosalityöskentely. Affirmatiivinen konteksti selittÀÀ sitĂ€, kuinka deliberatiivisessa edustamisessa tarvitaan muita oman mielipiteen punnintaan, peilaamiseen ja vahvistamiseen. Operatiivinen konteksti lĂ€htee ajatuksesta, ettĂ€ edustamisessa halutaan saada asioita tehdyksi ja aikaiseksi. TĂ€mĂ€ edellyttÀÀ kansanedustajilta yhteistyötĂ€, kompromissikyvykkyyttĂ€ sekĂ€ myös tavoitteellista ja strategista deliberaatiota. Viimeiseksi, performativiisessa kontekstissa deliberatiivinen edustaminen osoittaa ettĂ€ ”asioita on saatu aikaiseksi”. Deliberaation tasapuolisuutta ja kuuntelevuutta korostavat elementit liudentuvat istuntosalityöskentelyssĂ€. MenestyksekĂ€s kansanedustaja kykenee toimimaan kaikissa edellĂ€ mainituissa konteksteissa: tietÀÀ asioista, mutta osoittaa myös kykyĂ€ kuunnella ja kunnioittaa muita sekĂ€ heidĂ€n mielipiteitÀÀn pystyessÀÀn samanaikaisesti ajamaan ja kommunikoimaan omia poliittisia tavoitteitaan. Deliberatiivisen edustamisen nĂ€kökulmasta todellinen jĂ€nnite onkin eduskunnan nĂ€kyvĂ€n ja nĂ€kymĂ€ttömĂ€n työn vĂ€lillĂ€ ja tĂ€mĂ€n ristiriidan esilletuomisessa

    Bureaucratic Ideals and Artisanal Reality Survival Strategies in the Production of Echigo \u3ci\u3eJ u\u3c/i\u3e

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    The production of Echigo j u, a fine Japanese ramie textile, is in crisis. Woven on a body-tension 100m from hand-plied threads and often incorporating detailed warp and weft kasuri (ikat), Echigo j u is arguably one of the most sophisticated extant bastfiber traditions in Japan, and perhaps the world. Media and researchers alike regularly laud its ancient production processes, but contemporary makers are facing the almost insurmountable challenge of remaining financially solvent in a rapidly diminishing kimono market, with an increasing scarcity of artisans. One reason that Echigo j u survives today is because it has been designated an important Intangible Cultural Property by the government of Japan. This designation, given only to a small number of outstanding craft traditions, stipulates adherence to a set of specific highly skilled and non-mechanized production processes. It is significant to note that four out of the five woven textile industries to which the government has granted this status require the use of labor-intensive hand-plied or hand-spun thread in both the warp and the weft. While the recognition and subsidies accompanying the Important Intangible Cultural Property designation have unquestionably benefited Echigo j u as a tradition, the high standards and expectations they have set for the industry have not always concurred with practical reality. At the crux of the problem is the fact that Echigo j u is made not by one artisan but by a complex system of divided labor. Each time even a single link is cut from the production chain of craftspeople, makers are forced to either discretely find alternative means and sources or face the very real prospect of losing their livelihood. Only after I had worked side-by-side for months with weavers and textile producers was it admitted to me that a dearth of local artisans has forced thread merchants to look abroad for handplied thread

    Implementation of higher-order absorbing boundary conditions for the Einstein equations

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    We present an implementation of absorbing boundary conditions for the Einstein equations based on the recent work of Buchman and Sarbach. In this paper, we assume that spacetime may be linearized about Minkowski space close to the outer boundary, which is taken to be a coordinate sphere. We reformulate the boundary conditions as conditions on the gauge-invariant Regge-Wheeler-Zerilli scalars. Higher-order radial derivatives are eliminated by rewriting the boundary conditions as a system of ODEs for a set of auxiliary variables intrinsic to the boundary. From these we construct boundary data for a set of well-posed constraint-preserving boundary conditions for the Einstein equations in a first-order generalized harmonic formulation. This construction has direct applications to outer boundary conditions in simulations of isolated systems (e.g., binary black holes) as well as to the problem of Cauchy-perturbative matching. As a test problem for our numerical implementation, we consider linearized multipolar gravitational waves in TT gauge, with angular momentum numbers l=2 (Teukolsky waves), 3 and 4. We demonstrate that the perfectly absorbing boundary condition B_L of order L=l yields no spurious reflections to linear order in perturbation theory. This is in contrast to the lower-order absorbing boundary conditions B_L with L<l, which include the widely used freezing-Psi_0 boundary condition that imposes the vanishing of the Newman-Penrose scalar Psi_0.Comment: 25 pages, 9 figures. Minor clarifications. Final version to appear in Class. Quantum Grav

    Biomass production and feeding value of whole-crop cereal-legume-silages

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    In eastern Finland, several mixtures of spring wheat, spring barley, spring oats and/or rye with vetches and/or peas were evaluated in field experiments in 2005-2007 for their dry matter procuction, crude protein concentration and digestibility using three different harvesting times

    Stable radiation-controlling boundary conditions for the generalized harmonic Einstein equations

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    This paper is concerned with the initial-boundary value problem for the Einstein equations in a first-order generalized harmonic formulation. We impose boundary conditions that preserve the constraints and control the incoming gravitational radiation by prescribing data for the incoming fields of the Weyl tensor. High-frequency perturbations about any given spacetime (including a shift vector with subluminal normal component) are analyzed using the Fourier-Laplace technique. We show that the system is boundary-stable. In addition, we develop a criterion that can be used to detect weak instabilities with polynomial time dependence, and we show that our system does not suffer from such instabilities. A numerical robust stability test supports our claim that the initial-boundary value problem is most likely to be well-posed even if nonzero initial and source data are included.Comment: 27 pages, 4 figures; more numerical results and references added, several minor amendments; version accepted for publication in Class. Quantum Gra

    An axisymmetric evolution code for the Einstein equations on hyperboloidal slices

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    We present the first stable dynamical numerical evolutions of the Einstein equations in terms of a conformally rescaled metric on hyperboloidal hypersurfaces extending to future null infinity. Axisymmetry is imposed in order to reduce the computational cost. The formulation is based on an earlier axisymmetric evolution scheme, adapted to time slices of constant mean curvature. Ideas from a previous study by Moncrief and the author are applied in order to regularize the formally singular evolution equations at future null infinity. Long-term stable and convergent evolutions of Schwarzschild spacetime are obtained, including a gravitational perturbation. The Bondi news function is evaluated at future null infinity.Comment: 21 pages, 4 figures. Minor additions, updated to agree with journal versio

    Lag time determination in DEC measurements with PTR-MS

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    The disjunct eddy covariance (DEC) method has emerged as a popular technique for micrometeorological flux measurements of volatile organic compounds (VOCs). It has usually been combined with proton transfer reaction mass spectrometry (PTR-MS), an online technique for VOC concentration measurements. However, the determination of the lag time between wind and concentration measurements has remained an important challenge. To address this issue, we studied the effect of different lag time methods on DEC fluxes. The analysis was based on both actual DEC measurements with PTR-MS and simulated DEC data derived from high frequency H&lt;sub&gt;2&lt;/sub&gt;O measurements with an infrared gas analyzer. Conventional eddy covariance fluxes of H&lt;sub&gt;2&lt;/sub&gt;O served as a reference in the DEC simulation. The individual flux measurements with PTR-MS were rather sensitive to the lag time methods, but typically this effect averaged out when the median fluxes were considered. The DEC simulation revealed that the maximum covariance method was prone to overestimation of the absolute values of fluxes. The constant lag time methods, one based on a value calculated from the sampling flow and the sampling line dimensions and the other on a typical daytime value, had a tendency to underestimate. The visual assessment method and our new averaging approach utilizing running averaged covariance functions did not yield statistically significant errors and thus fared better than the habitual choice, the maximum covariance method. Given this feature and the potential for automatic flux calculation, we recommend using the averaging approach in DEC measurements with PTR-MS. It also seems well suited to conventional eddy covariance applications when measuring fluxes near the detection limit

    Long Hours, Uneasy Feelings : Parliamentary Work in Denmark, Finland and Sweden

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    A correction has been published: Parliamentary Affairs, Volume 75, Issue 3, July 2022, Page 576, https://doi.org/10.1093/pa/gsab034Politicians' work pressure is gaining more attention in parliamentary studies. To participate in the discussion about governing under pressure, this article offers an interdisciplinary approach to investigate how representatives navigate within a flexible, limitless work culture. This article presents a new inquiry to re-examine contemporary political agency by combining cultural studies theories with empirical insights in Nordic countries. By analysing 52 semi-structured interviews with MPs in Denmark, Finland and Sweden, the study finds that politics attracts people who want to change the world, but these attributes may initiate a vicious cycle, taking the form of psychological strain.Peer reviewe
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