The quest for the solar g modes

Solar gravity modes (or g modes) -- oscillations of the solar interior for which buoyancy acts as the restoring force -- have the potential to provide unprecedented inference on the structure and dynamics of the solar core, inference that is not possible with the well observed acoustic modes (or p modes). The high amplitude of the g-mode eigenfunctions in the core and the evanesence of the modes in the convection zone make the modes particularly sensitive to the physical and dynamical conditions in the core. Owing to the existence of the convection zone, the g modes have very low amplitudes at photospheric levels, which makes the modes extremely hard to detect. In this paper, we review the current state of play regarding attempts to detect g modes. We review the theory of g modes, including theoretical estimation of the g-mode frequencies, amplitudes and damping rates. Then we go on to discuss the techniques that have been used to try to detect g modes. We review results in the literature, and finish by looking to the future, and the potential advances that can be made -- from both data and data-analysis perspectives -- to give unambiguous detections of individual g modes. The review ends by concluding that, at the time of writing, there is indeed a consensus amongst the authors that there is currently no undisputed detection of solar g modes.Comment: 71 pages, 18 figures, accepted by Astronomy and Astrophysics Revie

Preferences for befriending schemes: a survey of patients with severe mental illness

This paper presents independent research funded by the National Institute for Health Research (NIHR) under its Programme Grants for Applied Research Programme (Reference Number RP-PG-0611-20002). The funding body was not involved in, and did not influence, the design of the study, data collection, analysis or interpretation of the data. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health

Limits on active to sterile neutrino oscillations from disappearance searches in the MINOS, Daya Bay, and bugey-3 experiments

Searches for a light sterile neutrino have been performed independently by the MINOS and the Daya Bay experiments using the muon (anti)neutrino and electron antineutrino disappearance channels, respectively. In this Letter, results from both experiments are combined with those from the Bugey-3 reactor neutrino experiment to constrain oscillations into light sterile neutrinos. The three experiments are sensitive to complementary regions of parameter space, enabling the combined analysis to probe regions allowed by the Liquid Scintillator Neutrino Detector (LSND) and MiniBooNE experiments in a minimally extended four-neutrino flavor framework. Stringent limits on sin^2 2θμe are set over 6 orders of magnitude in the sterile mass-squared splitting Δm^2 41. The sterile-neutrino mixing phase space allowed by the LSND and MiniBooNE experiments is excluded for Δm^2 41 < 0.8 eV^2 at 95% CLs

Pulse generation and shaping using the ultra-high-power laser system: VULCAN

VULCAN is a multi-beam, multi-terawatt laser facility based on Nd:glass operating at 1053 nm. The system is highly versatile, supplying four experimental areas with laser radiation at a range of pulse durations from 700 fs to 20 ns, at fundamental frequency, frequency doubled, or, as a limited option, frequency tripled wavelengths. Beams are available in a number of geometries dictated by the university based programs, which at present include: cluster; line focus including x-ray laser oscillator/amplifier geometry; backlighting; probing; and chirped pulse amplification (CPA) configurations. The system has eight beams which can deliver synchronized long and short pulses including two beams which can deliver subpicosecond CPA pulses. The CPA capabilities on VULCAN are an integral part of the laser system, not only delivering sub-picosecond pulses, but allowing uncompressed pulses and multi-pulses to be delivered to the target areas synchronized with the nanosecond pulses. This paper describes the system configuration, details the means of pulse synchronization and presents some of the pulse manipulation techniques used on VULCAN to provide the laser requirements for the experimental program