About the holographic pseudo-Goldstone boson

Pseudo-Goldstone bosons in 4D strongly coupled theories have a dual description in terms of 5D gauge theories in warped backgrounds. We introduce systematic methods of computing the pseudo-Goldstone potential for an arbitrary warp factor in 5D. When applied to electroweak symmetry breaking, our approach clarifies the relation of physical observables to geometrical quantities in five dimensions.Comment: 16 page

Méthode pour un plan à moyen terme

The University of Geneva has at its disposal an innovative system of medium range planning in the form of 4-year development plans. These plans, written into the "Loi sur l'Université" (the University Act) and dated May 26, 1973, are administered by the Commission de développement (C.D.) (Development Commission), a standing advisory body to the vice-chancellor's office. The C.D. is made up of representatives of faculties and schools and is chaired by a vice-chancellor who also heads the Service de développement (S.D.) (Development Service) - a team of three researchers and their secretarial office. The S.D. is under the central administration and is responsible for studies, development of the plan and institutional research. The role of the C.D. is specific and is not limited only to planning. The C.D. lends itself well to university forecasting and, because of this, the qualitative and quantitative aspects of development are constantly compared. Thus, the term "development" covers a wide field of investigation and is not identified with a mere planning technique. Through this approach, two other ends are also sought: on the one hand, bringing academic structures into line with administrative ones, fan extremely important aspect in a typical European university) and. on the other hand, coordinating medium and long range planning (forecasting the number of students, space etc. J The article refers to the planning experience of the University of Geneva and is based, in the main, on the chapter entitled "Méthode " of the second development plan for the years 1977-1980.L'universite´ de Gene`ve dispose d'un syste`me original de planification d moyen terme sous forme des plans de de´veloppement quadriennaux. La responsabiblite´ de ces plans, inscrits dans la Loi sur l'Universite´ du 26 mai 1973, incombe a` la Commission de de´veloppement (C.D.), organe consultatif permanent du Rectorat. La Commission de de´veloppement est compose´e des repre´sentants des faculte´s et e´coles et est pre´side´e par un vice-recteur qui dirige e´galement le Service de de´veloppement (S.D. ~ trois collaborateurs scientifiques et le secre´tariat) appartenant a` l'administration centrale, charge´ d'e´tudes, d'e´laboration du plan et de la recherche institutionnelle. Le ro^le de la Commission de de´veloppement est spe´cifique et ne se limite pas a` la planification seulement. La C.D. est un lieu privile´gie´ de la re´flexion prospective de l'Universite´ et de ce fait, les aspects qualitatifs de de´veloppement sont constamment confronte´s aux aspects quantitatifs. Ainsi, le terme "de´veloppement"recouvre un vaste champ d'investigation et ne s'identifie pas a` une simple technique de planification. Par cette approche e´galement, deux autres buts sont vise´s: d'une part, l'harmonisation des structures acade´miques et administratives, chose particulie`rement importante dans une universite´ europe´enne typique et, d'autre part, la liaison entre la planification a` moyen terme et celle a` long terme (pre´vision du nombre d'e´tudiants, des locaux, etc.) L'article se re´fe`re a` l'expe´rience de la planification a` l'Universite´ de Gene`ve et se base en grande partie sur le chapitre "Me´thode"du deuxie`me plan de de´veloppement pour les anne´es 1977-1980

Electroweak Precision Observables and the Unhiggs

We compute one-loop corrections to the S and T parameters in the Unhiggs scenario. In that scenario, the Standard Model Higgs is replaced by a non-local object, called the Unhiggs, whose spectral function displays a continuum above the mass gap. The Unhiggs propagator has effectively the same UV properties as the Standard Model Higgs propagator, which implies that loop corrections to the electroweak precision observables are finite and calculable. We show that the Unhiggs is consistent with electroweak precision tests when its mass gap is at the weak scale; in fact, it then mimics a light SM Higgs boson. We also argue that the Unhiggs, while being perfectly visible to electroweak precision observables, is invisible to detection at LEP.Comment: 13 pages; v2: references added, discussion of production cross-section expande

FIRe glider: Mapping in situ chlorophyll variable fluorescence with autonomous underwater gliders

Nutrient and light availability regulate phytoplankton physiology and photosynthesis in the ocean. These physiological processes are difficult to sample in time and space over physiologically and ecologically relevant scales using traditional shipboard techniques. Gliders are changing the nature of data collection, by allowing a sustained presence at sea over regional scales, collecting data at resolution not possible using traditional techniques. The integration of a fluorescence induction and relaxation (FIRe) sensor in a Slocum glider allows autonomous high‐resolution and vertically‐resolved measurements of photosynthetic physiological variables together with oceanographic data. In situ measurements of variable fluorescence under ambient light allows a better understanding of the physical controls of primary production (PP). We demonstrate this capability in a laboratory setting and with several glider deployments in the Southern Ocean. Development of these approaches will allow for the in situ evaluation of phytoplankton light stress and photoacclimation mechanisms, as well as the role of vertical mixing in phytoplankton dynamics and the underlying physiology, especially in remote locations and for prolonged duration

Community dynamics mining

In this paper we propose a model to analyze community dynamics. Recently, several methods and tools have been proposed to extract communities from static graphs. However, since communities are not static, but change over time, it is necessary to provide methods to determine and observe the community transitions and to extract the factors that cause the development. We regard a community as an object that exists over time and propose to observe community transitions along the time axis. For this we partition the time axis under observation by time windows. In each time window, a set of interactions between community participants is aggregated. These static networks are analyzed for subcommunities by applying community detection mechanisms. Through this we detect communities in each interval and can observe if communities persist over time or undergo a transition. We present community transitions and the observable indicators for the respective development. We furthermore present a software environment that incorporates several community detection and analysis methods to analyze community transitions. It supports a dynamic temporal community analysis and provides several forms of visualizations and analysis settings thus providing an interactive tool to observe community dynamics

Holography, Pade Approximants and Deconstruction

We investigate the relation between holographic calculations in 5D and the Migdal approach to correlation functions in large N theories. The latter employs Pade approximation to extrapolate short distance correlation functions to large distances. We make the Migdal/5D relation more precise by quantifying the correspondence between Pade approximation and the background and boundary conditions in 5D. We also establish a connection between the Migdal approach and the models of deconstructed dimensions.Comment: 28 page

Soft-Wall Stabilization

We propose a general class of five-dimensional soft-wall models with AdS metric near the ultraviolet brane and four-dimensional Poincar\'e invariance, where the infrared scale is determined dynamically. A large UV/IR hierarchy can be generated without any fine-tuning, thus solving the electroweak/Planck scale hierarchy problem. Generically, the spectrum of fluctuations is discrete with a level spacing (mass gap) provided by the inverse length of the wall, similar to RS1 models with Standard Model fields propagating in the bulk. Moreover two particularly interesting cases arise. They can describe: (a) a theory with a continuous spectrum above the mass gap which can model unparticles corresponding to operators of a CFT where the conformal symmetry is broken by a mass gap, and; (b) a theory with a discrete spectrum provided by linear Regge trajectories as in AdS/QCD models.Comment: 27 pages, 6 figures, 1 table. v2: references added, version to appear in NJP Focus Issue on Extra Dimension

Constraints for the existence of flat and stable non-supersymmetric vacua in supergravity

We further develop on the study of the conditions for the existence of locally stable non-supersymmetric vacua with vanishing cosmological constant in supergravity models involving only chiral superfields. Starting from the two necessary conditions for flatness and stability derived in a previous paper (which involve the Kahler metric and its Riemann tensor contracted with the supersymmetry breaking auxiliary fields) we show that the implications of these constraints can be worked out exactly not only for factorizable scalar manifolds, but also for symmetric coset manifolds. In both cases, the conditions imply a strong restriction on the Kahler geometry and constrain the vector of auxiliary fields defining the Goldstino direction to lie in a certain cone. We then apply these results to the various homogeneous coset manifolds spanned by the moduli and untwisted matter fields arising in string compactifications, and discuss their implications. Finally, we also discuss what can be said for completely arbitrary scalar manifolds, and derive in this more general case some explicit but weaker restrictions on the Kahler geometry.Comment: 22 pages, Latex, no figure

Warped Domain Wall Fermions

We consider Kaplan's domain wall fermions in the presence of an Anti-de Sitter (AdS) background in the extra dimension. Just as in the flat space case, in a completely vector-like gauge theory defined after discretizing this extra dimension, the spectrum contains a very light charged fermion whose chiral components are localized at the ends of the extra dimensional interval. The component on the IR boundary of the AdS space can be given a large mass by coupling it to a neutral fermion via the Higgs mechanism. In this theory, gauge invariance can be restored either by taking the limit of infinite proper length of the extra dimension or by reducing the AdS curvature radius towards zero. In the latter case, the Kaluza-Klein modes stay heavy and the resulting classical theory approaches a chiral gauge theory, as we verify numerically. Potential difficulties for this approach could arise from the coupling of the longitudinal mode of the light gauge boson, which has to be treated non-perturbatively

Supersymmetric branes with (almost) arbitrary tensions

We present a supersymmetric version of the two-brane Randall-Sundrum scenario, with arbitrary brane tensions T_1 and T_2, subject to the bound |T_{1,2}| \leq \sqrt{-6\Lambda_5}, where \Lambda_5 < 0 is the bulk cosmological constant. Dimensional reduction gives N=1, D=4 supergravity, with cosmological constant \Lambda_4 in the range \half\Lambda_5 \leq \Lambda_4 \leq 0. The case with \Lambda_4 = 0 requires T_1 = -T_2 = \sqrt{-6\Lambda_5}. This work unifies and generalizes previous approaches to the supersymmetric Randall-Sundrum scenario. It also shows that the Randall-Sundrum fine-tuning is not a consequence of supersymmetry.Comment: 19pp; Published versio