On the Landau-Ginzburg description of Boundary CFTs and special Lagrangian submanifolds

We consider Landau-Ginzburg (LG) models with boundary conditions preserving A-type N=2 supersymmetry. We show the equivalence of a linear class of boundary conditions in the LG model to a particular class of boundary states in the corresponding CFT by an explicit computation of the open-string Witten index in the LG model. We extend the linear class of boundary conditions to general non-linear boundary conditions and determine their consistency with A-type N=2 supersymmetry. This enables us to provide a microscopic description of special Lagrangian submanifolds in C^n due to Harvey and Lawson. We generalise this construction to the case of hypersurfaces in P^n. We find that the boundary conditions must necessarily have vanishing Poisson bracket with the combination (W(\phi)-\bar{W}(\bar{\phi})), where W(\phi) is the appropriate superpotential for the hypersurface. An interesting application considered is the T^3 supersymmetric cycle of the quintic in the large complex structure limit.Comment: 28+1 pages; no figures; requires JHEP.cls, amssymb; (v2) typo corrected; (v3) references adde

Worldsheet approaches to D-branes on supersymmetric cycles

We consider D-branes wrapped around supersymmetric cycles of Calabi-Yau manifolds from the viewpoint of N=2 Landau-Ginzburg models with boundary as well as by consideration of boundary states in the corresponding Gepner models. The Landau-Ginzburg approach enables us to provide a target space interpretation for the boundary states. The boundary states are obtained by applying Cardy's procedure to combinations of characters in the Gepner models which are invariant under spectral flow. We are able to relate the two descriptions using the common discrete symmetries of the two descriptions. We are thus able to provide an extension to the boundary of the bulk correspondence between Landau-Ginzburg orbifolds and the corresponding Gepner models.Comment: 28 pages, LaTeX with revtex; (v2) Condition involving superpotential in the boundary LG model imposed, references included ; (v3) final version to appear in journa

Impact of exchange rate changes on domestic inflation: a study of a small Pacific Island economy

This paper investigates the effect of changes in exchange rate on consumer price level, in Fiji, known as exchange rate pass-through during a thirty year period (1982-2009). Specifically, three time periods are focused on: the pre-coup years (1982-1986); post coup years (1987-2009); and full time period (1982-2009). Monthly data on consumer price index, nominal exchange rate, monetary aggregate and interest rate are utilized. The study results show that the degree of exchange rate pass-through to domestic price was relatively low during the entire sample period at 0.183. It was 0.453 and 0.373 for the pre and post coups periods. Regardless of the sample periods under study, the monetary aggregate, as a variable plays a pivotal in stabilizing the price level.Exchange rate pass-through, price, monetary measure, cointegration, Granger causality

Impact of global growth fluctuations on India: an empirical study

The article examines how growth fluctuations in major trading partner countries of the world have affected the Indian economy since its liberalization from the mid 1990s. This empirical study confirms that domestic output of India was strongly influenced by global shocks. The findings are not surprising as India’s trade and financial integration with the rest of the world has been on the rise.Economic integration, global shock, regional shock, India

Role of Remittances in Economic Development: An Empirical Study of World’s Two Most Remittances Dependent Pacific Island Economies

In the context of the ongoing world-wide recession and the consequent dim prospects for exports from small Pacific island countries, mobilization of foreign exchange earnings assumes considerable importance. The dependency of Samoa and Tonga on inward remittances is well known, as the two Polynesian island countries in recent years have been amongst the first top ten remittance recipient countries of the world. This paper examines the long-run nexus between economic growth and inward remittances during a three-decade period (1981-2008). The paper also discusses some important policy implications arising out of the study findings.Remittances, financial sector development, economic growth, bounds test, Samoa, Tonga

ShapeCodes: Self-Supervised Feature Learning by Lifting Views to Viewgrids

We introduce an unsupervised feature learning approach that embeds 3D shape information into a single-view image representation. The main idea is a self-supervised training objective that, given only a single 2D image, requires all unseen views of the object to be predictable from learned features. We implement this idea as an encoder-decoder convolutional neural network. The network maps an input image of an unknown category and unknown viewpoint to a latent space, from which a deconvolutional decoder can best "lift" the image to its complete viewgrid showing the object from all viewing angles. Our class-agnostic training procedure encourages the representation to capture fundamental shape primitives and semantic regularities in a data-driven manner---without manual semantic labels. Our results on two widely-used shape datasets show 1) our approach successfully learns to perform "mental rotation" even for objects unseen during training, and 2) the learned latent space is a powerful representation for object recognition, outperforming several existing unsupervised feature learning methods.Comment: To appear at ECCV 201

Boundary Fermions, Coherent Sheaves and D-branes on Calabi-Yau manifolds

We construct boundary conditions in the gauged linear sigma model for B-type D-branes on Calabi-Yau manifolds that correspond to coherent sheaves given by the cohomology of a monad. This necessarily involves the introduction of boundary fields, and in particular, boundary fermions. The large-volume monodromy for these D-brane configurations is implemented by the introduction of boundary contact terms. We also discuss the construction of D-branes associated to coherent sheaves that are the cohomology of complexes of arbitrary length. We illustrate the construction using examples, specifically those associated with the large-volume analogues of the Recknagel-Schomerus states with no moduli. Using some of these examples we also construct D-brane states that arise as bound states of the above rigid configurations and show how moduli can be counted in these cases

Microstructures in rapidly solidified Ni-Mo alloys

Ni-Mo alloys of compositions ranging from pure Ni to Ni-40 at % Mo were rapidly solidified by Chill Block Melt Spinning in vacuum and were examined by optical metallography, X-ray diffraction and transmission electron microscopy. Rapid solidification resulted in an extension of molybdenum solubility in nickel from 28 to 37.5 at %. A number of different phases and microstructures were seen at different depths (solidification conditions) from the quenched surface of the melt spun ribbons

D-branes and the Conifold Singularity

We analyze in detail the description of type IIB theory on a Calabi-Yau three-fold near a conifold singularity in terms of intersecting D-branes. In particular we study the singularity structure of higher derivative $F$-terms of the form $F_g W^{2g}$ where $W$ is the gravitational superfield. This singularity is expected to be due to a one -loop contribution from a charged soliton hypermultiplet becoming massless at the conifold point. In the intersecting D-brane description this soliton is described by an open string stretched between the two D-branes. After identifying the graviphoton vertex as a closed string operator we show that $F_g$'s have the expected singularity structure in the limit of vanishing soliton mass.Comment: Latex file, 14 page