University of St Andrews

About: University of St Andrews is a education organization based out in St Andrews, Fife, United Kingdom. It is known for research contribution in the topics: Population & Laser. The organization has 16260 authors who have published 43364 publications receiving 1636072 citations. The organization is also known as: St Andrews University & University of St. Andrews.

ESG Integration and the Investment Management Process: Fundamental Investing Reinvented

Abstract: We investigate how conventional asset man- agers account for environmental, social, and governance (ESG) factors in their investment process. We do so on the basis of an international survey among fund managers. We find that many conventional managers integrate responsible investing in their investment process. Furthermore, we find that ESG information in particular is being used for red flagging and to manage risk. We find that many conven- tional fund managers have already adopted features of re- sponsible investing in the investment process. Furthermore, we argue and show that ESG investing is highly similar to fundamental investing. We also reveal that there is a sub- stantial difference in the ways in which U.S. and European asset managers view ESG.

Compact Focusing Grating Couplers for Silicon-on-Insulator Integrated Circuits

Abstract: We report experimental results on compact and broadband focusing grating couplers, both in silicon-on-insulator (SOI) and gold on SOI. An eight-fold length reduction of the coupling structure from fiber to photonic wire in SOI, as compared to a linear grating and adiabatic taper, is obtained, without performance penalty. A proof of principle is given for a focusing grating coupler in gold on SOI, with 20% fiber-to-focus efficiency.

Steady State Evolution of Debris Disks around A Stars

Abstract: In this paper a simple analytical model for the steady-state evolution of debris disks due to collisions is confronted with Spitzer observations of dust around main sequence A stars. All stars are assumed to have planetesimal belts with a distribution of initial masses and radii. In the model disk mass is constant until the largest planetesimals reach collisional equilibrium whereupon the mass falls off ∝ t −1 age. Using parameters that are reasonable within the context of planet formation models and observations of proto-planetary disks, the detection statistics and trends seen at both 24 and 70 µm can be fitted well by the model. While there is no need to invoke stochastic evolution or delayed stirring to explain the detection statistics of dust around A stars, the model is also consistent with a moderate rate of stochastic events. Potentially anomalous systems are identified by their high ratio of observed dust luminosity to the maximum permissible in the model given their radii and ages, f/fmax; these are HD3003, HD38678, HD115892, and HD172555. It is not clear if their planetesimals have unusual properties (e.g., high strength or low eccentricity), or if their dust is a transient phenomenon. There are also well-studied examples from the literature where transient phenomena are favored (e.g., Vega, HD69830). However, the overall success of our model, which assumes planetesimals in all belts have the same strength, eccentricity and maximum size, suggests there is a large degree of uniformity in the outcome of planet formation. The distribution of the radii of the planetesimal belts, once corrected for detection bias, is found to follow N(r) ∝ r −0.8±0.3 in the range 3-120 AU. Since the inner edge of a belt is often attributed to an unseen planet, this provides a unique constraint on the planetary systems of A stars. It is also shown that the effect of P-R drag on the inner edge of A star disks may need to be considered for those close to the Spitzer detection threshold, such as HD2262, HD19356, HD106591, and HD115892. Predictions are made for the upcoming SCUBA-2 survey, including that at least 17 of the 100 A stars should be detectable above 2 mJy at 850 µm, illustrating how this model can be readily applied to the interpretation of future surveys. Subject headings: circumstellar matter – planetary systems: formation

Direct observation of spin-polarized bulk bands in an inversion-symmetric semiconductor

Abstract: The coupling between spin, valley and layer degrees of freedom in transition-metal dichalcogenides is shown to give rise to spin-polarized electron states, providing opportunities to create and manipulate spin and valley polarizations in bulk solids. Methods to generate spin-polarized electronic states in non-magnetic solids are strongly desired to enable all-electrical manipulation of electron spins for new quantum devices1. This is generally accepted to require breaking global structural inversion symmetry1,2,3,4,5. In contrast, here we report the observation from spin- and angle-resolved photoemission spectroscopy of spin-polarized bulk states in the centrosymmetric transition-metal dichalcogenide WSe2. Mediated by a lack of inversion symmetry in constituent structural units of the bulk crystal where the electronic states are localized6, we show how spin splittings up to ∼0.5 eV result, with a spin texture that is strongly modulated in both real and momentum space. Through this, our study provides direct experimental evidence for a putative locking of the spin with the layer and valley pseudospins in transition-metal dichalcogenides7,8, of key importance for using these compounds in proposed valleytronic devices.

The first WASP public data release

Abstract: The WASP (wide angle search for planets) project is an exoplanet transit survey that has been automatically taking wide field images since 2004. Two instruments, one in La Palma and the other in South Africa, continually monitor the night sky, building up light curves of millions of unique objects. These light curves are used to search for the characteristics of exoplanetary transits. This first public data release (DR1) of the WASP archive makes available all the light curve data and images from 2004 up to 2008 in both the Northern and Southern hemispheres. A web interface (www.wasp.le.ac.uk/public/) to the data allows easy access over the Internet. The data set contains 3 631 972 raw images and 17 970 937 light curves. In total the light curves have 119 930 299 362 data points available between them.