Search results for " theories"
showing 10 items of 278 documents
Observational signatures of Higgs inflation
2016
We investigate the dependency of Higgs inflation on the non-renormalisable matching between the low energy Standard Model limit and the inflationary regime at high energies. We show that for the top mass range $m_t \gtrsim 171.8$ GeV the scenario robustly predicts the spectral index $n_s \simeq 0.97$ and the tensor-to-scalar ratio $r\simeq 0.003$. The matching is however non-trivial, even the best-fit values $m_h=125.09$ GeV and $m_t=173.21$ GeV require a jump $\delta \lambda \sim 0.01$ in the Higgs coupling below the inflationary scale. For $m_t\lesssim 171.8$ GeV, the matching may generate a feature in the inflationary potential. In this case the predicted values of $n_s$ and $r$ vary but…
Fostering creative thinking : the role of primary teachers
2014
Τα τελευταία χρόνια παρατηρείται μια αυξανόμενη απαίτηση για δημιουργικότητα σε όλους τους τομείς της ανθρώπινης δραστηριότητας. Η πρωτοβάθμια εκπαίδευση πασχίζει να συμβαδίσει με τις νέες κοινωνικοοικονομικές ανάγκες και να προετοιμάσει τους δημιουργικούς πολίτες του μέλλοντος. Αν και οι εκπαιδευτικοί της πρωτοβάθμιας εκπαίδευσης παίζουν καθοριστικό ρόλο, άλλοτε θετικό και άλλοτε αρνητικό, στην καλλιέργεια της δημιουργικότητας των μαθητών, λίγες έρευνες έχουν διεξαχθεί σχετικά με τη συμβολή τους στην καλλιέργεια της δημιουργικής σκέψης των μαθητών και τις απόψεις τους για το θέμα αυτό. Η θεμελιωμένη γνώση (situated knowledge) των Ελλήνων εκπαιδευτικών πρωτοβάθμιας εκπαίδευσης και η εμπειρί…
Reading-related Cognitive Deficits in Spanish Developmental Dyslexia
2014
Abstract Spanish-speaking children learn to read words written in a relatively transparent orthography. Variations in orthographic transparency may shape the manifestation of reading difficulties. This study was intended to help clarify the nature of developmental dyslexia in Spanish. Developmentally Dyslexic children (DD) were compared to a chronological age-matched control group (CA). Measures included rapid automated naming, verbal working memory, phonological short-term memory, and phonemic awareness. Results demonstrated that developmental dyslexics show reading-related cognitive deficits in areas such as naming speed, verbal working memory, phonological short-term memory, and phonemic…
Early signs of dyslexia from the speech and language processing of children
2009
The Jyvaskyla Longitudinal Study of Dyslexia project (JLD) has followed the development of 200 children from birth until 10 years of age. Half the children are from families in which at least one of the parents has dyslexia, thus the child has a high risk of becoming dyslexic, and half have no such risk. Here the main findings of four studies in linguistics from the JLD project are reviewed. The speech processing skills were studied in 6, 18, 24 and 30-month-old children. The findings show that early signs of dyslexia can be detected in speech processing both phonologically and morphosyntactically. These precursors can be seen in perception or production of duration, in the prosody and phon…
The ATLAS Inner Detector commissioning and calibration
2010
The ATLAS Inner Detector is a composite tracking system consisting of silicon pixels, silicon strips and straw tubes in a 2 T magnetic field. Its installation was completed in August 2008 and the detector took part in data-taking with single LHC beams and cosmic rays. The initial detector operation, hardware commissioning and insitu calibrations are described. Tracking performance has been measured with 7.6 million cosmic-ray events, collected using a tracking trigger and reconstructed with modular pattern-recognition and fitting software. The intrinsic hit efficiency and tracking trigger efficiencies are close to 100%. Lorentz angle measurements for both electrons and holes, specific energ…
Dynamical formation of a Reissner-Nordström black hole with scalar hair in a cavity
2016
In a recent Letter [Sanchis-Gual et al., Phys. Rev. Lett. 116, 141101 (2016)], we presented numerical relativity simulations, solving the full Einstein--Maxwell--Klein-Gordon equations, of superradiantly unstable Reissner-Nordstr\"om black holes (BHs), enclosed in a cavity. Low frequency, spherical perturbations of a charged scalar field trigger this instability. The system's evolution was followed into the nonlinear regime, until it relaxed into an equilibrium configuration, found to be a hairy BH: a charged horizon in equilibrium with a scalar field condensate, whose phase is oscillating at the (final) critical frequency. Here, we investigate the impact of adding self-interactions to the …
Classical Field Theory of Gravitation
2012
The classical field theories developed in the preceding chapters all have in common that they are formulated on a flat spacetime, i.e. on a four-manifold which is a Euclidean space and which locally is decomposable into a direct product M 4 = ℝR3 ℝR of a physical space ℝR3 x of motions, and a time axis ℝRt. The first factor is the threedimensional space as it is perceived by an observer at rest while the time axis displays the (coordinate) time that he/she measures on his/her clocks. This spacetime is endowed with the Poincare group as the invariance group of physical laws and inherits the corresponding specific causality structure.
Sub-MeV dark matter and the Goldstone modes of superfluid helium
2019
We show how the relativistic effective field theory for the superfluid phase of helium-4 can replace the standard methods used to compute the production rates of low momentum excitations due to the interaction with an external probe. This is done by studying the scattering problem of a light dark matter particle in the superfluid, and comparing to some existing results. We show that the rate of emission of two phonons, the Goldstone modes of the effective theory, gets strongly suppressed for sub-MeV dark matter particles due to a fine cancellation between two different tree-level diagrams in the limit of small exchanged momenta. This phenomenon is found to be a consequence of the particular…
Equivalent-Single-Layer discontinuous Galerkin methods for static analysis of multilayered shells
2021
Abstract An original formulation for the elastic analysis of multilayered shells is presented in this work. The key features of the formulation are: the representation of the shell mean surface via a generic system of curvilinear coordinates; the unified treatment of general shell theories via an Equivalent-Single-Layer approach based on the through-the-thickness expansion of the covariant components of the displacement field; and an Interior Penalty discontinuous Galerkin scheme for the solution of the set of governing equations. The combined use of these features enables a high-order solution of the multilayered shell problem. Several numerical tests are presented for isotropic, orthotrop…
Higgs production and decay in models of a warped extra dimension with a bulk Higgs
2014
Warped extra-dimension models in which the Higgs boson is allowed to propagate in the bulk of a compact AdS5 space are conjectured to be dual to models featuring a partially composite Higgs boson. They offer a framework with which to investigate the implications of changing the scaling dimension of the Higgs operator, which can be used to reduce the constraints from electroweak precision data. In the context of such models, we calculate the cross section for Higgs production in gluon fusion and the H → γγ decay rate and show that they are finite (at one-loop order) as a consequence of gauge invariance. The extended scalar sector comprising the Kaluza-Klein excitations of the Standard Model …