Inhomogeneity and Nonlinear Preheating

We investigated the possibility that nonlinear gravitational effects influence the preheating era after inflation, using numerical solutions of the inhomogeneous Einstein field equations. We compared our results to perturbative calculations and to solutions of the nonlinear field equations in a rigid (unperturbed) spacetime, in order to isolate gravitational phenomena. We confirm the broad picture of preheating obtained from the nonlinear field equations in a rigid background, but find gravitational effects have a measurable impact on the dynamics. The longest modes in the simulation grow much more rapidly in the relativistic calculation than with a rigid background. We used the Weyl tensor to quantify the departure from homogeneity in the universe. We saw no evidence for the sort of gravitational collapse that leads to the formation of primordial black holes.Comment: Talk given at Marcel Grossmann Meeting IX. 3 pages, 1 figur

Scotland and Wales wait for the Supreme Court referee on Brexit

As the UK government refers the Scottish and Welsh bills to alter inherited EU law to the Supreme Court, Richard Parry (University of Edinburgh) discusses the interacting policies on devolution and Brexit

A critical examination of Bion's concept of containment and Winnicott's concept of holding, and their psychotherapeutic implications.

Wilfred Bion’s concept of the container/contained and Donald Winnicott’s concept of holding are two concepts that have had a profound influence on the development of psychoanalysis over the last half century. They are frequently used interchangeably in the literature and are often seen as denoting essentially the same clinical practice. It is the author’s contention that there are substantial differences between the two concepts and the models of mind that underpin them, and how they are translated into clinical practice. The models of mind and developmental trajectories that underpin the concepts of containment and holding are explicated fully, demonstrating some of the clear differences between the foundations of these two concepts. Further, through the use of clinical vignettes, the substantial differences between holding and containment in clinical practice were elucidated