2,664 research outputs found
Unimodular homotopy algebras and Chern-Simons theory
Quantum Chern-Simons invariants of differentiable manifolds are analyzed from
the point of view of homological algebra. Given a manifold M and a Lie (or,
more generally, an L-infinity) algebra g, the vector space H^*(M) \otimes g has
the structure of an L-infinity algebra whose homotopy type is a homotopy
invariant of M. We formulate necessary and sufficient conditions for this
L-infinity algebra to have a quantum lift. We also obtain structural results on
unimodular L-infinity algebras and introduce a doubling construction which
links unimodular and cyclic L-infinity algebras.Comment: 37 pages, expanded introduction and made minor correction
Minimal models of quantum homotopy Lie algebras via the BV-formalism
Using the BV-formalism of mathematical physics an explicit construction for
the minimal model of a quantum L-infinity-algebra is given as a formal super
integral. The approach taken herein to these formal integrals is axiomatic;
they can be approached using perturbation theory to obtain combinatorial
formulae as shown in the appendix. Additionally, there exists a canonical
differential graded Lie algebra morphism mapping formal functions on homology
to formal functions on the whole space. An L-infinity-algebra morphism inverse
to this differential graded Lie algebra morphism on the level of homology is
constructed as a formal super integral.Comment: 23 pages. Updated presentation with thanks to Paul Levy, Jim
Stasheff, Ted Voronov, and the anonymous referee at JM
“¿Quién empezó este arte y de dónde viene?” Una historia enmarcada sobre los orígenes de la alquimia en el Libro del árbol de ziziphus de los más lejanos confines de Pseudo-Ibn Waḥšīya
This paper explores the context of a Hermetic frame story in the pseudepigraphical alchemical treatise The Book of the Ziziphus Tree of the Furthest Boundary (Kitāb Sidrat almuntahā). The treatise is attributed to a prominent figure in the Arabic occult sciences, Abū Bakr b. Waḥshīya (fl. first half of the 4th/10th century). It was written in the form of a dialogue between the protagonist, Ibn Waḥshīya, and an alchemist from the Islamic West, al-Maghribī al-Qamarī. The last section of the introductory dialogue between these two characters consists of a frame story on the origins of alchemy and a legend of discovery (Fundlegende) that introduces a cosmogony and an allegorical depiction of the process of transmutation. Both the frame story and the legend of discovery abound in Hermetic motifs and topoi known from other Greek and Arabic alchemical treatises. The exposition of the different prevailing theories on the beginnings of alchemy reflects, moreover, historical phenomena, such as the Graeco-Arabic translation movement and the shu‘ūbīya controversy. Consistent with the literary tradition of the Arabic Hermetica, Ancient Egypt emerges in this treatise as the cradle of alchemy; however, I suggest that more than merely literary convention, such evocations express a genuine fascination with Ancient Egypt and its surviving material culture. In this respect, the littleknown genre of Arabic books on hidden treasure might shed new light on common Hermetic narratives and their circulation in Arabic occult literature.Este trabajo explora el contexto de una historia enmarcada del hermetismo en el tratado alquímico seudoepigráfico de El libro del árbol de ziziphus de los más lejanos confines (Kitāb Sidrat al-muntahā). El tratado, que se atribuye a una de las figuras más prominentes de las ciencias árabes ocultas, Abū Bakr b. Waḥšīya (primera mitad del siglo IV/X), está escrito en forma de diálogo entre el protagonista, Ibn Waḥšīya y un alquimista del Occidente islámico, al-Magribī al-Qamarī. La última sección del diálogo introductorio entre estos dos personajes se compone de una historia marco sobre los orígenes de la alquimia y la leyenda de su descubrimiento (Fundlegende) que presenta un texto con una cosmogonía y una representación alegórica del proceso de transmutación. Tanto en la historia enmarcada como en la leyenda del descubrimiento abundan tópicos y motivos herméticos conocidos en otros tratados alquímicos griegos y árabes. La exposición de las diferentes teorías prevalecientes sobre los orígenes de la alquimia refleja, además, fenómenos históricos de la civilización islámica pre-moderna, tales como el movimiento de traducción greco-árabe y la controversia de la šuʿūbīya. Como es propio en la tradición literaria de la Hermetica árabe, Egipto aparece en este tratado como la cuna de la alquimia, pero el autor de este artículo sostiene que la fascinación por Egipto y su cultura material no son una mera convención literaria. En este sentido, el casi desconocido género de libros árabes sobre el tesoro escondido podría arrojar nueva luz sobre narrativas herméticas comunes y su circulación en el Islam medieval
COMPASS results on transverse-spin asymmetries in two-hadron production in SIDIS
COMPASS is a fixed-target experiment at the CERN M2 beamline, with a rich physics program in spectroscopy and nucleon structure. The nucleon spin structure is investigated using a 160 GeV/c polarized μ+ beam and polarized solid state targets. The measurements of single-spin asymmetries in semi-inclusive deep inelastic scattering (SIDIS) on a transversely polarized target are an important part of the COMPASS physics program. A transversely polarized 6LiD (deuteron) target was used in 2002–2004. After taking the first data on a transversely polarized NH3 (proton) target in 2007, a full year of data taking followed in 2010 to increase precision. In this contribution we present for the first time the results from the 2010 data for the azimuthal asymmetries in two-hadron production which allow to investigate the transversity distribution function coupled to the two-hadron interference
fragmentation function (FF)
A checklist for choosing between R packages in ecology and evolution
The open source and free programming language R is a phenomenal mechanism to address a multiplicity of challenges in ecology and evolution. It is also a complex ecosystem because of the diversity of solutions available to the analyst.
Packages for R enhance and specialize the capacity to explore both niche data/experiments and more common needs. However, the paradox of choice or how we select between many seemingly similar options can be overwhelming and lead to different potential outcomes.
There is extensive choice in ecology and evolution between packages for both fundamental statistics and for more specialized domain‐level analyses.
Here, we provide a checklist to inform these decisions based on the principles of resilience, need, and integration with scientific workflows for evidence.
It is important to explore choices in any analytical coding environment—not just R—for solutions to challenges in ecology and evolution, and document this process because it advances reproducible science, promotes a deeper understand of the scientific evidence, and ensures that the outcomes are correct, representative, and robust.York University Librarie
Homotopy BV algebras in Poisson geometry
We define and study the degeneration property for BV-infinity algebras and
show that it implies that the underlying L-infinity algebras are homotopy
abelian. The proof is based on a generalisation of the well-known identity
\Delta(e^x)=e^x(\Delta(x)+[x,x]/2) which holds in all BV algebras. As an
application we show that the higher Koszul brackets on the cohomology of a
manifold supplied with a generalised Poisson structure all vanish.Comment: 13 pages, some minor typos correcte
QSO Absorption Line Constraints on Intragroup High-Velocity Clouds
We show that the number statistics of moderate redshift MgII and Lyman limit
absorbers may rule out the hypothesis that high velocity clouds are infalling
intragroup material.Comment: 4 pages, no figures; submitted to Astrophysical Journal Letters;
revised version, more general and includes more about Braun and Burton CHVC
An exploratory qualitative study of values issues associated with training and practice in pluralistic counselling
Background: A pluralistic model of practice has become increasingly influential in recent years. A distinctive feature of this approach is its explicit grounding within a philosophical and moral perspective.Aim: The aim of this study was to investigate issues and challenges that pluralistic counsellors experience in relation to values dilemmas that arise in practice.Methodology: Twelve practitioners, of various experience levels, who identified as pluralistic counsellors, were invited to take part in semi-structured interviews. Transcripts were analysed using a method of thematic analysis.Findings: Participants viewed their personal values to be compatible with the values that they perceived pluralistic counselling to hold, and reported that they chose pluralism as a modality because they found a similarity between their personal values and the values of pluralistic counselling. Core values associated with pluralistic practice included the following: the importance of connection, ‘there is no one right way to be’, equality (not taking an expert role), honesty, and willingness to make use of research evidence. Participants also described value dilemmas, and their use of supervision in dealing with value issues.Implications: The implications of these findings for training, research and practice are discussed
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