Embedding Branes in Flat Two-time Spaces

We show how non-near horizon, non-dilatonic $p$-brane theories can be obtained from two embedding constraints in a flat higher dimensional space with 2 time directions. In particular this includes the construction of D3 branes from a flat 12-dimensional action, and M2 and M5 branes from 13 dimensions. The worldvolume actions are found in terms of fields defined in the embedding space, with the constraints enforced by Lagrange multipliers.Comment: LaTex, 8 pages. Contribution to the TMR Conference on Quantum aspects of gauge theories, supersymmetry and unification. Paris, 1-7 September 199

Superspace calculation of the four-loop spectrum in N=6 supersymmetric Chern-Simons theories

Using N=2 superspace techniques we compute the four-loop spectrum of single trace operators in the SU(2) x SU(2) sector of ABJM and ABJ supersymmetric Chern-Simons theories. Our computation yields a four-loop contribution to the function h^2(\lambda) (and its ABJ generalization) in the magnon dispersion relation which has fixed maximum transcendentality and coincides with the findings in components given in the revised versions of arXiv:0908.2463 and arXiv:0912.3460. We also discuss possible scenarios for an all-loop function h^2(\lambda) that interpolates between weak and strong couplings.Comment: LaTeX, feynmp, 34 pages; v2: typos corrected, formulations improved, references adde

BIOMECHANIC EVALUATION OF RUNNING PERFORMANCES

Running is the final result of a very complex coordination involving a lot of different anatomo-physiological supports that are jointly provided by the neuro-muscular, the cardio-vascular, the respiratory and the metabolic systems. Given the obvious difficulties of a detailed evaluation of this specific motor-action, a method for synthetic description and analysis of the running performance has been developed. Such a method, presently tested by taking into account the sagittal plane only), is essentially based on the computation of three suitable indexes (namely P2-D, Kv, q) which integrates the information coming from both kinematic and dynamic data. The index P2-D provides a synthesis of the mean power developed by muscles at the main lower limb joints during the ground contact phase. The index Kv depends on the ratio between the previous index P2-D and the mean kinetic energy developed by the whole body during running. The third index q, pointing out an information which is similar to the well known mechanical efficiency, is depending on the ratio between the running cadence and the previously cited index K, The proposed method has been tested by taking into account various subjects who were running at different mean speed. The kinematic and dynamic data which are necessary to implement the computation of the above three indexes have been captured by using opto-electronic motion analyser (Elite system) and a piezoelectric sensed force plate. The aim of this work is to present in detail the adopted mathematical approach and to discuss, on the basis of some preliminary results, the sensitivity of the proposed method

Conformal boundary and geodesics for AdS5×S5AdS_5\times S^5 and the plane wave: Their approach in the Penrose limit

Projecting on a suitable subset of coordinates, a picture is constructed in which the conformal boundary of $AdS_5\times S^5$ and that of the plane wave resulting in the Penrose limit are located at the same line. In a second line of arguments all $AdS_5\times S^5$ and plane wave geodesics are constructed in their integrated form. Performing the Penrose limit, the approach of null geodesics reaching the conformal boundary of $AdS_5\times S^5$ to that of the plane wave is studied in detail. At each point these null geodesics of $AdS_5\times S^5$ form a cone which degenerates in the limit.Comment: some statements refined, chapter 5 rewritten to make it more precise, some typos correcte

Approaching the transit time limit for high-precision spectroscopy on metastable CO around 6 μm

We present a high-resolution spectroscopy experiment, based on a molecular beam setup, which pushes the measured line width close to the transit time limit, on the order of 100 kHz

The Penetration–Aspiration Scale: Adaptation to Open Partial Laryngectomy and Reliability Analysis

A standard for assessing swallowing function after open partial horizontal laryngectomy (OPHL) is still not established. The variability in the measures used to investigate swallowing functional outcomes after OPHL limits the communication among clinicians and the possibility to compare and combine results from different studies. The study aims to adapt the PAS to the altered anatomy after OPHLs using fiberoptic endoscopic evaluation of swallowing (FEES) and to test its reliability. To adapt the PAS, two landmarks were identified: the entry of the laryngeal vestibule and the neoglottis. Ninety patients who underwent an OPHL were recruited (27 type I, 31 type II and 32 type III). FEES was performed and video-recorded. Two speech and language therapists (SLTs) independently rated each FEES using the PAS adapted for OPHL (OPHL-PAS). FEES recordings were rated for a second time by both SLTs at least 15 days from the first video analysis. Inter- and intra-rater agreement was assessed using unweighted Cohen's kappa. Overall, inter-rater agreement of the OPHL-PAS was k\u2009=\u20090.863, while intra-rater agreement was k\u2009=\u20090.854. Concerning different OPHL types, inter- and intra-rater agreement were k\u2009=\u20090.924 and k\u2009=\u20090.914 for type I, k\u2009=\u20090.865 and k\u2009=\u20090.790 for type II, and k\u2009=\u20090.808 and k\u2009=\u20090.858 for type III, respectively. The OPHL-PAS is a reliable scale to assess the invasion of lower airway during swallowing in patients with OPHL using FEES. The study represents the first attempt to define standard tools to assess swallowing functional outcome in this population

Isometric Embedding of BPS Branes in Flat Spaces with Two Times

We show how non-near horizon p-brane theories can be obtained from two embedding constraints in a flat higher dimensional space with 2 time directions. In particular this includes the construction of D3 branes from a flat 12-dimensional action, and M2 and M5 branes from 13 dimensions. The worldvolume actions are determined by constant forms in the higher dimension, reduced to the usual expressions by Lagrange multipliers. The formulation affords insight in the global aspects of the spacetime geometries and makes contact with recent work on two-time physics.Comment: 29 pages, 10 figures, Latex using epsf.sty and here.sty; v2: reference added and some small correction

Predictions for PP-wave string amplitudes from perturbative SYM

The role of general two-impurity multi-trace operators in the BMN correspondence is explored. Surprisingly, the anomalous dimensions of all two-impurity multi-trace BMN operators to order g_2^2\lambda' are completely determined in terms of single-trace anomalous dimensions. This is due to suppression of connected field theory diagrams in the BMN limit and this fact has important implications for some string theory processes on the PP-wave background. We also make gauge theory predictions for the matrix elements of the light-cone string field theory Hamiltonian in the two string-two string and one string-three string sectors.Comment: 46 pages, 12 figures. V3:typos correcte