University of Southampton

About: University of Southampton is a education organization based out in Southampton, United Kingdom. It is known for research contribution in the topics: Population & Laser. The organization has 37184 authors who have published 99400 publications receiving 3462915 citations. The organization is also known as: Southampton University & Soton Uni.

GW190412: Observation of a binary-black-hole coalescence with asymmetric masses

Abstract: We report the observation of gravitational waves from a binary-black-hole coalescence during the first two weeks of LIGO’s and Virgo’s third observing run. The signal was recorded on April 12, 2019 at 05∶30∶44 UTC with a network signal-to-noise ratio of 19. The binary is different from observations during the first two observing runs most notably due to its asymmetric masses: a ∼30 M⊙ black hole merged with a ∼8 M⊙ black hole companion. The more massive black hole rotated with a dimensionless spin magnitude between 0.22 and 0.60 (90% probability). Asymmetric systems are predicted to emit gravitational waves with stronger contributions from higher multipoles, and indeed we find strong evidence for gravitational radiation beyond the leading quadrupolar order in the observed signal. A suite of tests performed on GW190412 indicates consistency with Einstein’s general theory of relativity. While the mass ratio of this system differs from all previous detections, we show that it is consistent with the population model of stellar binary black holes inferred from the first two observing runs.

Percolation, quantum tunnelling and the integer Hall effect

Abstract: A model is introduced for Anderson localisation in the integer quantum Hall regime. The model represents a system with a disordered potential that varies slowly on the scale of the magnetic length, but includes quantum tunnelling and interference effects. Numerical calculations indicate that the localisation length diverges only at the centre of each Landau band. The scaling behaviour near the mobility edge is analysed: results suggest that quantum tunnelling induces crossover at the classical percolation threshold to critical behaviour similar to that found previously for a rapidly varying potential.

Optical Manifestations of Planar Chirality

Abstract: We report that planar chiral structures affect the polarization state of light in a manner similar to three-dimensional chiral (optical active) media. In experiments with artificial metal-on-silicon chiral planar gratings of 442 wallpaper group symmetry, containing millions of chiral elements per square centimeter, we observed rotation of the polarization azimuth in excess of 30_ of light diffracted from it. The rotation was found to change its sign for two enantiomeric forms of the media and to have components associated with both the structural arrangement and the chirality of individual structural elements.

Social functioning in depression: a review

Abstract: OBJECTIVE: This article reviews the available data on social functioning in depression and provides clinical guidelines and opinion on this important and expanding field. DATA SOURCES: A MEDLINE search was conducted to identify all English-language articles (1988-1999) using the search terms depression and social functioning, depression and social adjustment, depression and psychosocial functioning, and social functioning and antidepressant. Further articles were obtained from the bibliographies of relevant articles. DATA SYNTHESIS: Depressive disorders are frequently associated with significant and pervasive impairments in social functioning, often substantially worse than those experienced by patients with other chronic medical conditions. The enormous personal, social, and economic impact of depression, due in no small part to the associated impairments in social functioning, is often underappreciated. Both pharmacologic and psychotherapeutic approaches can improve social impairments, although there is a lack of extended, randomized controlled trials in this area using consistent assessment criteria. CONCLUSION: Despite this lack, it is becoming clear that not all treatments are equally effective in relieving the impaired social functioning associated with depressive disorders. Furthermore, efficacy in relieving the core symptoms of depression does not necessarily guarantee efficacy in relieving impaired social functioning.