Four curious supergravities

We consider four supergravities with 16+16, 32+32, 64+64, 128+128 degrees of freedom displaying some curious properties: (1) They exhibit minimal supersymmetry (N=1, 2, 2, 1) but maximal rank (r=7, 6, 4, 0) of the scalar coset in D=4, 5, 7, 11. (2) They couple naturally to supermembranes and admit these membranes as solutions. (3) Although the D=4, 5, 7 supergravities follow from truncating the maximally supersymmetric ones, there nevertheless exist M-theory compactifications with G2, SU(3), SU(2) holonomy having these supergravities as their massless sectors. (4) They reduce to N=1, 2, 4, 8 theories all with maximum rank 7 in D=4 which (5) correspond to 0, 1, 3, 7 lines of the Fano plane and hence admit a division algebra (R,C,H,O) interpretation consistent with the black-hole/qubit correspondence, (6) are generalized self-mirror and hence (7) have vanishing on-shell trace anomaly.Comment: 16 pages late

Flat Symplectic Bundles of N-Extended Supergravities, Central Charges and Black-Hole Entropy

In these lectures we give a geometrical formulation of N-extended supergravities which generalizes N=2 special geometry of N=2 theories. In all these theories duality symmetries are related to the notion of "flat symplectic bundles" and central charges may be defined as "sections" over these bundles. Attractor points giving rise to "fixed scalars" of the horizon geometry and Bekenstein-Hawking entropy formula for extremal black-holes are discussed in some details.Comment: Based on lectures given by S. Ferrara at the 5th Winter School on Mathematical Physics held at the Asia Pacific Center for Theoretical Physics, Seul (Korea), February 199

Public attitudes towards intellectual disabilities after watching Olympic/Paralympic performance

Despite there being some changes to the way that people with Intellectual Disabilities (ID) are viewed in society, negative attitudes prevail. One of the aspirations of the Paralympic games 2012 organisers was to influence the public’s attitudes towards disabled people. The aim of this study was to investigate whether stimuli depicting people with ID performing at a Paralympic level of sport can change attitudes towards ID. A mixed randomised comparison group design was employed comparing two groups; those who viewed Paralympic level ID sport footage and information, and those who viewed Olympic footage and information on measures of implicit attitudes towards disability and explicit attitudes towards people with ID. One hundred and fourteen students at a UK university were administered the measures pre and post the stimuli presentation. Implicit attitudes significantly changed in a positive direction from T1 to T2 for both groups. Attitudes of empowerment increased from T1-T2, nearing significance. The findings provide evidence that Paralympic (ID) and Olympic footage plus written information seems to change attitudes towards people with ID, at least in the short term. Viewing elite sports information and footage may have at least a short term effect on attitudes towards ID which provides some tentative support to one of the London 2012 legacy promises. However it does not seem to matter which footage people are exposed to. Given both types of stimuli proved effective it suggests the possible role of affect in changing attitudes through the media, which warrants further investigation

Orbits of Exceptional Groups, Duality and BPS States in String Theory

We give an invariant classification of orbits of the fundamental representations of exceptional groups $E_{7(7)}$ and $E_{6(6)}$ which classify BPS states in string and M theories toroidally compactified to d=4 and d=5. The exceptional Jordan algebra and the exceptional Freudenthal triple system and their cubic and quartic invariants play a major role in this classification. The cubic and quartic invariants correspond to the black hole entropy in d=5 and d=4, respectively. The classification of BPS states preserving different numbers of supersymmetries is in close parallel to the classification of the little groups and the orbits of timelike, lightlike and space-like vectors in Minkowski space. The orbits of BPS black holes in N=2 Maxwell-Einstein supergravity theories in d=4 and d=5 with symmetric space geometries are also classified including the exceptional N=2 theory that has $E_{7(-25)}$ and $E_{6(-26)}$ as its symmety in the respective dimensions.Comment: New references and two tables added, a new section on the orbits of N=2 Maxwell-Einstein supergravity theories in d=4 and d=5 included and some minor changes were made in other sections. 17 pages. Latex fil

Where are the missing cosmic metals ?

The majority of the heavy elements produced by stars 2 billion years after the Big Bang (redshift z~3) are presently undetected at those epochs. We propose a solution to this cosmic `missing metals' problem in which such elements are stored in gaseous halos produced by supernova explosions around star-forming galaxies. By using data from the ESO/VLT Large Program, we find that:(i) only 5%-9% of the produced metals reside in the cold phase, the rest being found in the hot (log T=5.8-6.4) phase; (ii) 1%-6% (3%-30%) of the observed CIV (OVI) is in the hot phase. We conclude that at z~3 more than 90% of the metals produced during the star forming history can be placed in a hot phase of the IGM, without violating any observational constraint. The observed galaxy mass-metallicity relation, and the intergalactic medium and intracluster medium metallicity evolution are also naturally explained by this hypothesis.Comment: 9 pages, 2 figures, ApJ Letters, in pres

Common business and housing market cycles in the Euro area from a multivariate decomposition.

The 2007 sub-prime crisis in the United States, prolonged by a severe economic recession spread over many countries around the world, has led many economic researchers to focus on the recent fluctuations in housing prices and their relationships with macroeconomics and monetary policies. The existence of common housing cycles among the countries of the euro zone could lead the European Central Bank to integrate more specifically the evolution of such asset prices in its assessment. In this paper, we implement a multivariate unobserved component model on housing market variables in order to assess the common euro area housing cycle and to evaluate its relationship with the economic cycle. Among the general class of multivariate unobserved component models, we implement the band-pass filter based on the trend plus cycle decomposition model and we allow the existence of two cycles of different periods. The dataset consists of gross domestic product and real house prices series for four main euro area countries (Germany, France, Italy and Spain). Empirical results show a strong relationship for business cycles in France, Italy and Spain. Moreover, French and Spanish house prices cycles appear to be strongly related, while the German one possesses its own dynamics. Finally, we find that GDP and house prices cycles are related in the medium-term for fluctuations between 4 and 8 years, while the housing market contributes to the long-term economic growth only in Spain and Germany.House prices, Business cycles, Euro area, Unobserved components model.

Freudenthal Dual Lagrangians

The global U-dualities of extended supergravity have played a central role in differentiating the distinct classes of extremal black hole solutions. When the U-duality group satisfies certain algebraic conditions, as is the case for a broad class of supergravities, the extremal black holes enjoy a further symmetry known as Freudenthal duality (F-duality), which although distinct from U-duality preserves the Bekenstein-Hawking entropy. Here it is shown that, by adopting the doubled Lagrangian formalism, F-duality, defined on the doubled field strengths, is not only a symmetry of the black hole solutions, but also of the equations of motion themselves. A further role for F-duality is introduced in the context of world-sheet actions. The Nambu-Goto world-sheet action in any (t, s) signature spacetime can be written in terms of the F-dual. The corresponding field equations and Bianchi identities are then related by F-duality allowing for an F-dual formulation of Gaillard-Zumino duality on the world-sheet. An equivalent polynomial "Polyakov- type" action is introduced using the so-called black hole potential. Such a construction allows for actions invariant under all groups of type E7, including E7 itself, although in this case the stringy interpretation is less clear.Comment: 1+16 pages, 1 Table, updated to match published versio