Moduli space of supersymmetric black holes in five dimensions

This thesis presents a classification of all asymptotically at, supersymmetric and biaxisymmetric (i.e. possessing a U(1)2-symmetry) soliton and black hole solutions to five-dimensional minimal supergravity. In particular, by combining local constraints from supersymmetry of the solutions with global constraints for stationary and bi-axisymmetric spacetimes, we show that any solution must be multi-centred with a Gibbons{Hawking base. We also find a refinement of the allowed horizon topologies of this class of solutions, to one of S3, S1 X S2 or a lens space L(p; 1). We construct the general, smooth solution associated with each possible rod structure, thereby finding a large moduli space of black hole spacetimes with noncontractible 2-cycles in the domain of outer communication. This includes examples for each of the allowed horizon topologies. In the absence of a black hole we obtain a classification of the known "bubbling" soliton spacetimes. We then move on to a systematic analysis of the subclass of three-centred solutions contained in the constructed moduli space, focusing on the special case of single black hole solutions. This class is composed of seven regular black hole solutions. We find that four of these can have the same conserved charges as the original spherical, supersymmetric black hole, the BMPV solution. These consist of a black lens with L(3; 1) horizon topology and three distinct families of spherical black holes with nontrivial topology outside the horizon. The former provides the first example of a nonspherical black hole with the same conserved charges as the BMPV black hole. Moreover, of these four solutions, three can have a greater entropy than the BMPV black hole near the BMPV upper spin bound. One of these is a previously known spherical black hole with nontrivial topology; the other two are new examples of a spherical black hole with nontrivial topology and an L(3; 1) black lens

Supersymmetric black hole non-uniqueness in five dimensions

We present a systematic study of the moduli space of asymptotically flat, supersymmetric and biaxisymmetric black hole solutions to five-dimensional minimal supergravity. Previously, it has been shown that such solutions must be multi-centred solutions with a Gibbons-Hawking base. In this paper we perform a full analysis of three-centred solutions with a single black hole, for which there are seven regular black hole solutions. We find that four of these can have the same conserved charges as the BMPV black hole. These consist of a black lens with L(3,1) horizon topology and three distinct families of spherical black holes with nontrivial topology outside the horizon. The former provides the first example of a nonspherical black hole with the same conserved charges as the BMPV black hole. Moreover, of these four solutions, three can have a greater entropy than the BMPV black hole near the BMPV upper spin bound. One of these is a previously known spherical black hole with nontrivial topology and the other two are new examples of a spherical black hole with nontrivial topology and an L(3,1) black lens.Comment: version 2: typos corrected, minor clarifications added; 26 pages, 10 figure

Moduli space of supersymmetric solitons and black holes in five dimensions

We determine all asymptotically flat, supersymmetric and biaxisymmetric soliton and black hole solutions to five dimensional minimal supergravity. In particular, we show that the solution must be a multi-centred solution with a Gibbons-Hawking base. The proof involves combining local constraints from supersymmetry with global constraints for stationary and biaxisymmetric spacetimes. This reveals that the horizon topology must be one of S^3, S^1 x S^2 or a lens space L(p,1), thereby providing a refinement of the allowed horizon topologies. We construct the general smooth solution for each possible rod structure. We find a large moduli space of black hole spacetimes with noncontractible 2-cycles for each of the allowed horizon topologies. In the absence of a black hole we obtain a classification of the known `bubbling' soliton spacetimes.Comment: v2: 43 pages, 5 figures, references added, typos fixed, minor clarifications, expanded discussion of physical parameters. v3: clarified statement of theorem 4 (results unchanged, update made after publication

Flat space cosmology and phase transitions in four dimensions

We generalize a phase transition between three-dimensional hot flat space and a cer- tain type of flat space cosmology to four dimensions. To do so, an analogue of this cosmology is constructed in four dimensions and novel flat space boundary conditions are established, that differ from the usual boundary conditions of asymptotically flat space in four dimensions. Also we construct the Lie algebra of asymptotic Killing vectors that preserve these boundary conditions. A generalization of the phase transition can then be found straightforwardly. We will find that there are some differences in possible interpretations as compared to the three-dimensional version, which will also be discussed.3

No antidepressant-like acute effects of bright light on emotional information processing in healthy volunteers

Rationale: Bright light treatment (BLT) is an efficacious antidepressant intervention, but its mechanism of action is not well understood. Antidepressant drugs acutely affect how emotional information is processed, pushing the brain to prioritise positive relative to negative input. Whether BLT could have a similar effect is not known to date. Objective: To test whether BLT acutely influences emotional information processing similar to antidepressant drugs, using an established healthy volunteer assay. Methods: Following a double-blind, parallel-group design, 49 healthy volunteers (18–65 years, 26 females) were randomly allocated to 60-min BLT (≥ 10,000 lux) or sham-placebo treatment early in the morning in autumn/winter. Immediately after treatment, emotional information processing was assessed using the Oxford Emotional Test Battery, a validated set of behavioural tasks tapping into emotional information processing in different cognitive domains. Participants also completed questionnaires before and after treatment to assess changes in subjective state. Results: The BLT group did not show significantly more positively biased emotional information processing compared to the placebo group (p > 0.05 for all measures). After adjustment for pre-treatment scores, there were also no significant post-treatment differences between groups in subjective state (p > 0.05 for all measures). Conclusions: BLT did not show immediate effects on emotional information processing in an established healthy volunteer assay. Thus, BLT might exert its clinical effects through a different (cognitive) mechanism than other antidepressant interventions. Future studies should corroborate this finding including clinical populations and more intensive treatment regimes, and control for potential chronobiological effects