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Collective nouns in Welsh: a noun category or a plural allomorph?
Get PDFA noun category in Welsh which has a shorter form for a collection/plural meaning and a suffixed singulative for a single instance has been described in the literature as both a number category and a plural allomorph, often with terminological ambiguity and blurring of boundaries between different noun types. This paper is an investigation of the features of these nouns using a number of theoretical approaches which cumulatively support the argument that collective can be considered a full number category in Welsh
Finite Size Scaling in 2D Causal Set Quantum Gravity
Get PDFWe study the N -dependent behaviour of 2d causal set quantum gravity. This theory is known to exhibit a phase transition as the analytic continuation parameter β, akin to an inverse temperature, is varied. Using a scaling analysis we find that the asymptotic regime is reached at relatively small values of N . Focussing on the 2d causal set action S, we find that β{S} scales like N^ν where the scaling exponent ν takes different values on either side of the phase transition. For β > β_c we find that ν = 2 which is consistent with our analytic predictions for a non-continuum phase in the large β regime. For β = 65
An algebraic approach to minimal models in CFTs
Get PDFCFTs are naturally defined on Riemann surfaces. The rational ones can be solved using methods from algebraic geometry. One particular feature is the covariance of the partition function under the mapping class group. In genus g = 1, one can apply the standard theory of modular forms, which can be linked to ordinary differential equations of hypergeometric type
IRAS 18153−1651: an H II region with a possible wind bubble blown by a young main-sequence B star
Get PDFWe report the results of spectroscopic observations and numerical modelling of the H II region IRAS 18153−1651. Our study was motivated by the discovery of an optical arc and two main-sequence stars of spectral type B1 and B3 near the centre of IRAS 18153−1651. We interpret the arc as the edge of the wind bubble (blown by the B1 star), whose brightness is enhanced by the interaction with a photoevaporation flow from a nearby molecular cloud. This interpretation implies that we deal with a unique case of a young massive star (the most massive member of a recently formed low-mass star cluster) caught just tens of thousands of years after its stellar wind has begun to blow a bubble into the surrounding dense medium. Our 2D, radiation-hydrodynamics simulations of the wind bubble and the H II region around the B1 star provide a reasonable match to observations, both in terms of morphology and absolute brightness of the optical and mid-infrared emission, and verify the young age of IRAS 18153−1651. Taken together our results strongly suggest that we have revealed the first example of a wind bubble blown by a main-sequence B star
Rational CFTs on Riemann surfaces
Get PDFThe partition function of rational conformal field theories (CFTs) on Riemann surfaces is expected to satisfy ODEs of Gauss-Manin type. We investigate the case of hyperelliptic surfaces and derive the ODE system for the (2, 5) minimal model
On D = 6, N = (2,0) and N = (4,0) Theories
Get PDFUsing a convolutive field-theoretic product, it is shown here that the “square” of an Abelian D = 6, N = (2, 0) theory yields the free D = 6, N = (4, 0) theory constructed by Hull, together with its generalised (super)gauge transformations. This offers a new perspective on the (4, 0) theory and chiral theories of conformal gravity more generally, while at the same time extending the domain of the “gravity = gauge × gauge” paradigm
On the Entanglement Entropy of Quantum Fields in Causal Sets
Get PDFIn order to understand the detailed mechanism by which a funda mental discreteness can provide a finite entanglement entropy, we con sider the entanglement entropy of two classes of free massless scalar fields on causal sets that are well approximated by causal diamonds in Minkowski spacetime of dimensions 2,3 and 4. The first class is defined from discretised versions of the continuum retarded Green functions, while the second uses the causal set’s retarded nonlocal d’Alembertians parametrised by a length scale l k . In both cases we provide numerical evidence that the area law is recovered when the double-cutoff pre scription proposed in [24] is imposed. We discuss in detail the need for this double cutoff by studying the effect of two cutoffs on the quan tum field and, in particular, on the entanglement entropy, in isolation. In so doing, we get a novel interpretation for why these two cutoff are necessary, and the different roles they play in making the entanglement entropy on causal sets finite
Early Modern Irish miscellanea
Get PDFFour studies mostly concerning Early Modern Irish language: (1) comparatio compendiaria; (2) a detail of vowel-shortening in hiatus; (3) the Bardic technical term 'áoi trasgartha'; (4) a rhyming example of 'dee' "gods"
Why resumption? Resumptive pronouns in prepositional relative clauses [in Old, Middle and Early Modern Irish]
Get PDFArgues that accessibility theory explains the distribution of resumptive pronouns in prepositional relative clauses in Old, Middle and Early Modern Irish