Spatial coherence of forward-scattered light in a turbid medium

We study spatially coherent forward-scattered light propagating in a turbid medium of moderate optical depth (0-9 mean free paths). Coherent detection was achieved by using a tilted heterodyne geometry, which desensitizes coherent detection of the attenuated incident light. We show that the degree of spatial coherence is significantly higher for light scattered only once in comparison with that for multiply scattered light and that it approaches a small constant value for large numbers of scattering events

A two-dimensional Fermi liquid with attractive interactions

We realize and study an attractively interacting two-dimensional Fermi liquid. Using momentum resolved photoemission spectroscopy, we measure the self-energy, determine the contact parameter of the short-range interaction potential, and find their dependence on the interaction strength. We successfully compare the measurements to a theoretical analysis, properly taking into account the finite temperature, harmonic trap, and the averaging over several two-dimensional gases with different peak densities

Nature-Inspired and Energy Efficient Route Planning

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Loudly sing cuckoo : More-than-human seasonalities in Britain

This research was funded by a grant from the Arts and Humanities Research Council, grant number AH/E009573/1.Peer reviewedPostprin

Questioning acoustemology: an interview with Steven Feld

This is the author accepted manuscript. The final version is available from Taylor & Francis via the DOI in this record.In this conversation transcript, Tom Rice asks Steve Feld a series of questions about ‘acoustemology’, a term Steve coined and which has become a key concept in sound studies. Referring to ‘acoustic epistemology’, a ‘knowing-with and knowing-through the audible’, acoustemology emerged in the context of Steve’s work on the Kaluli of Papua New Guinea and their intricate knowledge of the sounds of their rainforest environment (Feld 2015, 12). It has since been applied by Steve, and many others, in studies of sound in a wide variety of settings. Tom asks questions that have arisen as he tries to explore and clarify the implications of the term. For instance, are acoustemologies invariably culturally embedded, or can they also be understood to emerge independently of culture? To what extent are acoustemologies shaped by individual and personal preferences, experiences and abilities? Is it possible for one acoustemology to end and another begin or do acoustemologies merely shift in terms of the sounds to which they are orientated? Answering with illustrations from his own intellectual journey, Steve presents acoustemology as an open-ended concept which is generative rather than prescriptive and which invites ongoing empirical research and interdisciplinary discussio

Radio-Frequency Spectroscopy

Contains reports on three research projects

Gravity a la Born-Infeld

A simple technique for the construction of gravity theories in Born-Infeld style is presented, and the properties of some of these novel theories are investigated. They regularize the positive energy Schwarzschild singularity, and a large class of models allows for the cancellation of ghosts. The possible correspondence to low energy string theory is discussed. By including curvature corrections to all orders in alpha', the new theories nicely illustrate a mechanism that string theory might use to regularize gravitational singularities.Comment: 21 pages, 2 figures, new appendix B with corrigendum: Class. Quantum Grav. 21 (2004) 529

Pure functions in C: A small keyword for automatic parallelization

© 2020, The Author(s). The need for parallel task execution has been steadily growing in recent years since manufacturers mainly improve processor performance by increasing the number of installed cores instead of scaling the processor’s frequency. To make use of this potential, an essential technique to increase the parallelism of a program is to parallelize loops. Several automatic loop nest parallelizers have been developed in the past such as PluTo. The main restriction of these tools is that the loops must be statically analyzable which, among other things, disallows function calls within the loops. In this article, we present a seemingly simple extension to the C programming language which marks functions without side-effects. These functions can then basically be ignored when the automatic parallelizer checks the parallelizability of loops. We integrated the approach into the GCC compiler toolchain and evaluated it by running several real-world applications. Our experiments show that the C extension helps to identify additional parallelization opportunities and, thus, to significantly increase the performance of applications