SLED Phenomenology: Curvature vs. Volume

We assess the question whether the SLED (Supersymmetric Large Extra Dimensions) model admits phenomenologically viable solutions with 4D maximal symmetry. We take into account a finite brane width and a scale invariance (SI) breaking dilaton-brane coupling, both of which should be included in a realistic setup. Provided that the microscopic size of the brane is not tuned much smaller than the fundamental bulk Planck length, we find that either the 4D curvature or the size of the extra dimensions is unacceptably large. Since this result is independent of the dilaton-brane couplings, it provides the biggest challenge to the SLED program. In addition, to clarify its potential with respect to the cosmological constant problem, we infer the amount of tuning on model parameters required to obtain a sufficiently small 4D curvature. A first answer was recently given in [arXiv:1508.01124], showing that 4D flat solutions are only ensured in the SI case by imposing a tuning relation, even if a brane-localized flux is included. In this companion paper, we find that the tuning can in fact be avoided for certain SI breaking brane-dilaton couplings, but only at the price of worsening the phenomenological problem. Our results are obtained by solving the full coupled Einstein-dilaton system in a completely consistent way. The brane width is implemented using a well-known ring regularization. In passing, we note that for the couplings considered here the results of [arXiv:1508.01124] (which only treated infinitely thin branes) are all consistently recovered in the thin brane limit, and how this can be reconciled with the concerns about their correctness, recently brought up in [arXiv:1509.04201].Comment: 28 pages, 4 figure

Element distribution and noble gas isotopic abundances in lunar meteorite Allan Hills A81005

Antarctic meteorite ALLAN HILLS A81005, an anorthositic breccia, is recognized to be of lunar origin. The noble gases in this meteorite were analyzed and found to be solar-wind implanted gases, whose absolute and relative concentrations are quite similar to those in lunar regolith samples. A sample of this meteorite was obtained for the analysis of the noble gas isotopes, including Kr(81), and for the determination of the elemental abundances. In order to better determine the volume derived from the surface correlated gases, grain size fractions were prepared. The results of the instrumental measurements of the gamma radiation are listed. From the amounts of cosmic ray produced noble gases and respective production rates, the lunar surface residence times were calculated. It was concluded that the lunar surface time is about half a billion years

Brane Induced Gravity: From a No-Go to a No-Ghost Theorem

Numerous claims in the literature suggest that gravity induced on a higher co-dimensional surface violates unitarity in the weak coupling regime. However, it remained unclear, why a conserved source localized on this surface and giving rise to an induced gravity term at low energies would absorb and emit the associated ghost, given a consistent source-free theory. In this article it is shown that the appearance of the induced Einstein Hilbert term does not threaten the unitarity of the theory. The physics arguments behind this statement are presented in a semi-covariant language, but the detailed proof is given using Dirac's constraint analysis. It is shown that the would-be ghost highlighted in previous works is non-dynamical and therefore not associated with a state in the Hilbert space. As a result of these investigations, brane induced gravity goes without a ghost, opening an exciting window of opportunity for consistent deformations of gravity at the largest observable distances.Comment: 13 pages, v2: matches version published in Physical Review

Artrite e movimento

Bewegen ist ein zentrales Element für einen erfolgreichen Umgang mit einer rheumatoiden Arthritis (RA). Bewegen reduziert Schmerzen, Einschränkungen an Gelenken und Muskulatur, verbessert die Alltagsbewältigung, steigert allgemein die Gesundheit, das Wohlbefinden und die Fitness und hat damit einen grossen Einfluss auf die Lebensqualität. Gemäss neuer Forschung kann Bewegen sogar die Entzündung direkt positiv beeinflussen. Bewegen ist Medizin!Bouger est un élément essentiel pour bien gérer la polyarthrite rhumatoïde (PR). L’activité physique atténue les douleurs, améliore la motricité au niveau des muscles et des articulations, ainsi que la gestion du quotidien ou encore la santé, le bien-être et la forme en général, ce qui a donc une grande influence sur la qualité de vie. Selon les recherches récentes, le fait de bouger pourrait même avoir un effet positif directement sur l’inflammation. Bouger, c’est soigner!Il movimento è un tassello fondamentale per gestire efficacemente l’artrite reumatoide (AR). Muoversi riduce i dolori, le limitazioni articolari e muscolari, semplifica lo svolgimento delle attività quotidiane, migliora le condizioni generali di salute, il benessere e la forma fisica ed è pertanto determinante per la qualità di vita. Le più recenti ricerche mostrano che il movimento può addirittura influenzare direttamente e positivamente la flogosi. Muoversi è un toccasana

Microscopic Picture of Non-Relativistic Classicalons

A theory of a non-relativistic, complex scalar field with derivatively coupled interaction terms is investigated. This toy model is considered as a prototype of a classicalizing theory and in particular of general relativity, for which the black hole constitutes a prominent example of a classicalon. Accordingly, the theory allows for a non-trivial solution of the stationary Gross-Pitaevskii equation corresponding to a black hole in the case of GR. Quantum fluctuations on this classical background are investigated within the Bogoliubov approximation. It turns out that the perturbative approach is invalidated by a high occupation of the Bogoliubov modes. Recently, it was proposed that a black hole is a Bose-Einstein condensate of gravitons that dynamically ensures to stay at the verge of a quantum phase transition. Our result is understood as an indication for that claim. Furthermore, it motivates a non-linear numerical analysis of the model.Comment: 11 page

Non-perturbative aspects of galileon duality

We study quantum aspects of the galileon duality, especially in the case of a particular interacting galileon theory that is said to be dual to a free theory through the action of a simultaneous field and coordinate transformation. This would appear to map a theory with multiple vacua to one with a unique vacuum state. However, by regulating the duality transformation using external sources, we are able to preserve the full vacuum structure in the dual frame. By explicitly calculating the one-particle irreducible effective action on a maximally symmetric background, we identify a semi-classical contribution to the Wightman functions that has not been taken into account in previous analyses due to the singular point in the duality map. This may affect its spectral properties at high energy scales. These observations cast doubt on the main evidence in support of a non-local UV structure for galileons