Graviton-photon conversion on spin 0 and 1/2 particles

The differential cross-sections for scattering of gravitons into photons on bosons and fermions are calculated in linearized quantum gravity. They are found to be strongly peaked in the forward direction and become constant at high energies. Numerically, they are very small as expected for such gravitational interactions.Comment: 13 pages, LaTeX with 5 figure

Princess and the Pea at the nanoscale: Wrinkling and delamination of graphene on nanoparticles

Thin membranes exhibit complex responses to external forces or geometrical constraints. A familiar example is the wrinkling, exhibited by human skin, plant leaves, and fabrics, resulting from the relative ease of bending versus stretching. Here, we study the wrinkling of graphene, the thinnest and stiffest known membrane, deposited on a silica substrate decorated with silica nanoparticles. At small nanoparticle density monolayer graphene adheres to the substrate, detached only in small regions around the nanoparticles. With increasing nanoparticle density, we observe the formation of wrinkles which connect nanoparticles. Above a critical nanoparticle density, the wrinkles form a percolating network through the sample. As the graphene membrane is made thicker, global delamination from the substrate is observed. The observations can be well understood within a continuum elastic model and have important implications for strain-engineering the electronic properties of graphene.Comment: 11 pages, 8 figures. Accepted for publication in Physical Review

Solid rocket booster internal flow analysis by highly accurate adaptive computational methods

The primary objective of this project was to develop an adaptive finite element flow solver for simulating internal flows in the solid rocket booster. Described here is a unique flow simulator code for analyzing highly complex flow phenomena in the solid rocket booster. New methodologies and features incorporated into this analysis tool are described

Contextual perception under active inference

Human social interactions depend on the ability to resolve uncertainty about the mental states of others. The context in which social interactions take place is crucial for mental state attribution as sensory inputs may be perceived differently depending on the context. In this paper, we introduce a mental state attribution task where a target-face with either an ambiguous or an unambiguous emotion is embedded in different social contexts. The social context is determined by the emotions conveyed by other faces in the scene. This task involves mental state attribution to a target-face (either happy or sad) depending on the social context. Using active inference models, we provide a proof of concept that an agent’s perception of sensory stimuli may be altered by social context. We show with simulations that context congruency and facial expression coherency improve behavioural performance in terms of decision times. Furthermore, we show through simulations that the abnormal viewing strategies employed by patients with schizophrenia may be due to (i) an imbalance between the precisions of local and global features in the scene and (ii) a failure to modulate the sensory precision to contextualise emotions

Quality of life of adult congenital heart disease patients: a systematic review of the literature

Aims This review explores the quality of life of adult congenital heart disease patients and the relationship between disease severity and quality of life. METHODS: We searched seven electronic databases and the bibliography of articles. The 31 selected studies fulfilled the following criteria: adult population; quantitative; assessment of quality of life and/or impact of disease severity on quality of life using validated measures; English language. Data extraction forms were used to summarise the results. RESULTS: There are evident methodological limitations within the reviewed studies such as heterogeneous populations, designs, and quality of life conceptualisations and measurements. Despite these problems, findings suggest that the quality of life of adult congenital heart disease patients is compromised in the physical domain compared with their healthy counterparts, whereas no differences were found in relation to the psychosocial and environmental/occupational domain. Some severity variables appear to be significant correlates of quality of life and could be considered in a future standardised classification of disease severity. Conclusion The methodological limitations of past research in relation to the definition and measurement of quality of life, the study designs, and disease severity classifications need to be addressed in future studies in order to provide robust evidence and valid conclusions in this area of study. This will enable the development of targeted interventions for the improvement of quality of life in the adult population of congenital heart disease patients

Performing smart sexual selves: A sexual scripting analysis of youth talk about internet pornography

CAUL read and publish agreement 2023In this article, we explore young New Zealanders’ use of sexual scripts in talk about Internet pornography (IP) to perform ‘smart’ sexual selves. Using sexual scripting theory, as developed by feminist discursive psychologists, our analysis of interview data generated with 10 youth (aged 16–18 years) highlights two commonly constructed sexual identities across youth talk; (i) the proficient Internet pornography user, and (ii) the astute Internet pornography viewer. The way these young people talk about portrayals of sexuality and gender in IP – and their ability to discern its artifice – suggests they are savvy consumers who are capable of using IP as a cultural resource (e.g. for learning, entertainment) while at the same time acknowledging it as a flawed representation of sex and sexuality. We discuss the implications of our findings for strengths-based sexuality education that supports sexual agency, proposing a justice-orientated approach grounded in the notion of ethical sexual citizenship.fals

Public Opinion about Punishment and Corrections

Get tough control policies in the United States are often portrayed as the reflection of the public\u27s will: Americans are punitive and want offenders locked up. Research from the past decade both reinforces and challenges this assessment. The public clearly accepts, if not prefers, a range of punitive policies (e.g., capital punishment, three-strikes-and-you\u27re-out laws, imprisonment). But support for get-tough policies is mushy. Thus citizens may be willing to substitute a sentence of life imprisonment without parole for the death penalty. Especially when nonviolent offenders are involved, there is substantial support for intermediate sanctions and for restorative justice. Despite three decades of criticism, rehabilitation-particularly for the young-remains an integral part of Americans\u27 correctional philosophy. There is also widespread support for early intervention programs. In the end, the public shows a tendency to be punitive and progressive, wishing the correctional system to achieve the diverse missions of doing justice, protecting public safety, and reforming the wayward

Similarity between Kaluza-Klein and Open-string amplitudes in Diphoton Production

We calculate the tree-level open-string amplitudes for the scattering of four massless particles with diphoton final states. These amplitudes are required to reproduce those of standard model at the tree level in the low energy limit. After low energy stringy corrections, we found that they have similar form to the same processes induced by exchange of the Kaluza-Klein(KK) excitations of graviton in ADD scenario. Using this similarity, we apply constraints on the KK mass scale $M_D$ to the string scale $M_S$. The results are consistent with constraints from the 4-fermion scattering, about $0.6-0.9$ TeV.Comment: 10 pages, modified reference

GoSam: A program for automated one-loop Calculations

The program package GoSam is presented which aims at the automated calculation of one-loop amplitudes for multi-particle processes. The amplitudes are generated in terms of Feynman diagrams and can be reduced using either D-dimensional integrand-level decomposition or tensor reduction, or a combination of both. GoSam can be used to calculate one-loop corrections to both QCD and electroweak theory, and model files for theories Beyond the Standard Model can be linked as well. A standard interface to programs calculating real radiation is also included. The flexibility of the program is demonstrated by various examples.Comment: 10 pages, Talk given at the International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT), Uxbridge, London, September 201