Higher dimensional quantum communication in a curved spacetime: an efficient simulation of the propagation of the wavefront of a photon

A photon with a modulated wavefront can produce a quantum communication channel in a larger Hilbert space. For example, higher dimensional quantum key distribution (HD-QKD) can encode information in the transverse linear momentum (LM) or orbital angular momentum (OAM) modes of a photon. This is markedly different than using the intrinsic polarization of a photon. HD-QKD has advantages for free space QKD since it can increase the communication channel\~Os tolerance to bit error rate (BER) while maintaining or increasing the channels bandwidth. We describe an efficient numerical simulation of the propagation photon with an arbitrary complex wavefront in a material with an isotropic but inhomogeneous index of refraction. We simulate the waveform propagation of an optical vortex in a volume holographic element in the paraxial approximation using an operator splitting method. We use this code to analyze an OAM volume-holographic sorter. Furthermore, there are analogue models of the evolution of a wavefront in the curved spacetime environs of the Earth that can be constructed using an optical medium with a given index of refraction. This can lead to a work-bench realization of a satellite HD-QKD system.Comment: 20 pages, 7 figure

Book review: Social policy as a magpie : applying ruthlesspragmatism to real-world problems

Introducing social policy as a broadly conceived study of human wellbeing, Hartley Dean’s revised and updated Social Policy examines the ways in which governments and peoples throughout the world attend to, promote, neglect or even undermine the things that make life worth living

Truth and Lives: Beneath Our Skin

“Art can be fundamental to our collective understanding of who we are, what we believe, and how we relate to each other and our surroundings. Artists can weave the cultural fabric necessary for a sustainable, vibrant society.” (Surdna Foundation, 2016). With this in mind, I’ve sought to create a project aimed at generating insight, compassion and critical dialogue around the common threads of body diversity. Through a practice of relationship building with individuals from diverse and marginalized intersections of society, I’ve begun adapting stories, shared by participants, about how they live and thrive (or not) in their bodies. Adaptations are in both visual art format (2D and 3D) and digital catching of the creative process. The stories are then released in video format on the project website www.beneathourskin.org. The catch and release format of this process is aimed at broadening audience impact to create change in how culturally we view and treat our own bodies and the bodies of others. I’ve also engaged in a reflective process around personal impact and assessment with participants to gauge impact and change over time. My intent is to continue this work, growing it to a sustainable program with the potential to impact change for participants within themselves, their relationships and their community. Through participation, contribution and reflections upon seeing their own stories through a new publicly shared lens participants will experience personal change, while their stories help lift perceptions of body diversity into a new light exposing where ongoing societal change is needed

The Association Between Fruit and Vegetable Consumption and Mental Health Among Young Adults

While the majority of the American population is aware that fruits and vegetables can improve physical health, research also suggests that mental health may benefits as well. With depression and anxiety rates increasing and fruit and vegetable consumption decreasing across the country there is potential that the two are related. It has been found that majority of American adults do not meet fruit and vegetable recommendations, while 16 million adults face depression and anxiety. Young adults reported the lowest amount of fruit and vegetable consumption, as well as some of the highest rates of depression and anxiety. The purpose of the current study was to find if there is a relationship between fruit and vegetable consumption and mental health in young adults. The study gathered data on 113 American young adults, ages 18-25, and their recorded food intake and mental health using validated questionnaires and nutrition tools. The findings show a positive relationship between fruit intake and self-esteem, a negative correlation between fruit intake and cognitive dysregulation and lastly, a positive correlation between total fruit and vegetable intake and self-esteem. These findings support existing literature in that there is a correlation between fruit and vegetable consumption and mental health in young adults

David Stafford-Clark (1916-1999): seeing through a celebrity psychiatrist

This article uses the mass-media career of the British psychiatrist David Stafford-Clark (1916-1999) as a case study in the exercise of cultural authority by celebrity medical professionals in post-war Britain. Stafford-Clark rose to prominence in the mass media, particularly through his presenting work on medical and related topics for BBC TV and Radio, and was in the vanguard of psychiatrists and physicians who eroded professional edicts on anonymity. At the height of his career, he traded upon his celebrity status, and consequent cultural authority, to deliver mass media sermons on a variety of social, cultural, and political topics. Stafford-Clark tried to preserve his sense of personal and intellectual integrity by clinging to a belief that his authority in the public sphere was ultimately to be vindicated by his literary, intellectual, and spiritual significance. But as his credibility dwindled, he came to distrust the cultural intermediaries, such as broadcasters and publishers, who had supported him

The Angular Momenta of Neutron Stars and Black Holes as a Window on Supernovae

It is now clear that a subset of supernovae display evidence for jets and are observed as gamma-ray bursts. The angular momentum distribution of massive stellar endpoints provides a rare means of constraining the nature of the central engine in core-collapse explosions. Unlike supermassive black holes, the spin of stellar-mass black holes in X-ray binary systems is little affected by accretion, and accurately reflects the spin set at birth. A modest number of stellar-mass black hole angular momenta have now been measured using two independent X-ray spectroscopic techniques. In contrast, rotation-powered pulsars spin-down over time, via magnetic braking, but a modest number of natal spin periods have now been estimated. For both canonical and extreme neutron star parameters, statistical tests strongly suggest that the angular momentum distributions of black holes and neutron stars are markedly different. Within the context of prevalent models for core-collapse supernovae, the angular momentum distributions are consistent with black holes typically being produced in GRB-like supernovae with jets, and with neutron stars typically being produced in supernovae with too little angular momentum to produce jets via magnetohydrodynamic processes. It is possible that neutron stars are imbued with high spin initially, and rapidly spun-down shortly after the supernova event, but the available mechanisms may be inconsistent with some observed pulsar properties.Comment: ApJ Letters, accepte