Superforms in six-dimensional superspace

Indexación: Web of ScienceWe investigate the complex of differential forms in curved, six-dimensional, N = (1, 0) superspace. The superconformal group acts on this complex by super-Weyl transformations. An ambi-twistor-like representation of a second conformal group arises on a pure spinor subspace of the cotangent space. The p-forms are defined by super-Weylcovariant tensor fields on this pure spinor subspace. The on-shell dynamics of such fields is superconformal. We construct the superspace de Rham complex by successively obstructing the closure of forms. We then extend the analysis to composite forms obtained by wedging together forms of lower degree. Finally, we comment on applications to integration in curved superspace and propose a superspace formulation of the abelian limit of the non-abelian tensor hierarchy of N = (1, 0) superconformal models.http://link.springer.com/article/10.1007%2FJHEP05%282016%29016#aboutarticl

Noise Folding in Compressed Sensing

The literature on compressed sensing has focused almost entirely on settings where the signal is noiseless and the measurements are contaminated by noise. In practice, however, the signal itself is often subject to random noise prior to measurement. We briefly study this setting and show that, for the vast majority of measurement schemes employed in compressed sensing, the two models are equivalent with the important difference that the signal-to-noise ratio is divided by a factor proportional to p/n, where p is the dimension of the signal and n is the number of observations. Since p/n is often large, this leads to noise folding which can have a severe impact on the SNR

New Results in the CBF theory for medium-heavy nuclei

Momentum distributions, spectroscopic factors and quasi-hole wave functions of medium-heavy doubly closed shell nuclei have been calculated in the framework of the Correlated Basis Function theory, by using the Fermi hypernetted chain resummation techniques. The calculations have been done by using microscopic two-body nucleon-nucleon potentials of Argonne type, together with three-body interactions. Operator dependent correlations, up to the tensor channels, have been used.Comment: 6 pages, 3 figures, proceeding of the "XI Convegno su problemi di Fisica Nucleare Teorica" 11-14 Ottobre 2006, Cortona, Ital

Einstein-AdS action, renormalized volume/area and holographic Rényi entropies

Indexación: Scopus.The authors thank D.E. Díaz, P. Sundell and A. Waldron for interesting discussions. C.A. is a Universidad Andres Bello (UNAB) Ph.D. Scholarship holder, and his work is supported by Dirección General de Investigación (DGI-UNAB). This work is funded in part by FONDECYT Grants No. 1170765 “Boundary dynamics in anti-de Sitter gravity and gauge/gravity duality ” and No. 3180620 “Entanglement Entropy and AdS gravity ”, and CONICYT Grant DPI 20140115.We exhibit the equivalence between the renormalized volume of asymptotically anti-de Sitter (AAdS) Einstein manifolds in four and six dimensions, and their renormalized Euclidean bulk gravity actions. The action is that of Einstein gravity, where the renormalization is achieved through the addition of a single topological term. We generalize this equivalence, proposing an explicit form for the renormalized volume of higher even-dimensional AAdS Einstein manifolds. We also show that evaluating the renormalized bulk gravity action on the conically singular manifold of the replica trick results in an action principle that corresponds to the renormalized volume of the regular part of the bulk, plus the renormalized area of a codimension-2 cosmic brane whose tension is related to the replica index. Renormalized Rényi entropy of odd-dimensional holographic CFTs can thus be obtained from the renormalized area of the brane with finite tension, including the effects of its backreaction on the bulk geometry. The area computation corresponds to an extremization problem for an enclosing surface that extends to the AdS boundary, where the newly defined renormalized volume is considered. © 2018, The Author(s).https://link.springer.com/article/10.1007%2FJHEP08%282018%2913

Self-dual formulations of d=3 gravity theories in the path-integral framework

We study the connection, at the quantum level, between d=2+1 dimensional self-dual models with actions of growing (from first to fourth) order, governing the dynamics of helicity +2 (or -2) massive excitations. We obtain identities between generating functionals of the different models using the path-integral framework, this allowing to establish dual maps among relevant vacuum expectation values. We check consistency of these v.e.v.'s with the gauge invariance gained in each mapping.Comment: 26 pages. LaTeX. Minor changes. Published in Int. J Modern Phys. A; http://www.worldscinet.com/ijmp

Exposure Therapy: Stimulus Intensity as a Factor in Treatment Preference

Currently, a host of treatments are available for treating anxiety disorders, including specific phobia. Treatment of specific phobia includes pharmacological, psychosocial, and combined approaches. Exposure therapy, however, is considered the leading psychological treatment for specific phobia, and has shown to be effective. Exposure therapy challenges held beliefs about feared stimuli/situations and attempts to integrate new learning about the feared object/situation. Despite exposure being effective to treat specific phobia, it is associated with low adherence and high dropout rates. There is a need to examine, therefore, ways to improve patient adherence for exposure. A way to examine this issue is to assess patient preferences for currently available treatments for specific phobia, and to examine directly the various methods for delivering exposure (e.g., stimuli intensity presentation). Furthermore, it is important to assess individuals’ perception of efficacy on various methods of delivering exposure stimuli (e.g., low intensity versus high intensity). Also, it is essential to examine individual willingness to engage in different presentation of stimuli intensity. Participants (N = 1,065) were assessed for dental care-related fear and anxiety, and 279 of those individuals with high levels of fear/anxiety were included in the analyses regarding treatment preferences. Participants rated their preference for types of treatments (e.g., exposure, flooding, systematic desensitization) and were asked to rank order-based on personal preference. Then participants watched two video examples of exposure (i.e., low intensity and high intensity) and asked to rate their preference for the two methods to deliver exposure stimuli. After, participants rank ordered several approaches for delivering exposure stimuli by personal preference. Finally, participants were given a free choice to watch either a black screen (e.g., avoidance), low intensity exposure video, or high intensity exposure video over three trials. Results indicated that participants rated relaxation as the most preferred type of treatment for dental phobia. In regard to exposure stimuli, participants rated the low intensity exposure stimuli with greater preference (e.g., more efficacious and more willing to engage in the treatment) than the high intensity exposure stimuli. A majority of participants watched the low intensity (39.6%) and the avoidance video (32.8%) two or more times over the three trials demonstrating a behavioral preference for video content. A Latent Class Analysis suggested distinct groups (i.e., Low to Avoidant, and Avoidant) based on the patterns of video choice over the three trials. Findings of this study highlight differences in patient preferences for specific phobia treatment, which ultimately can impact oral health care services and training. Utilizing low intensity exposure stimuli may be a promising way to get patient buy-in and ease into higher intensity stimuli and possible improve treatment outcomes

Efficacy of Self-Directed Exposure Using Smart Phone Technology: First versus Third Person Perspective

Exposure therapy, including its self-directed forms, is effective for treatment of specific phobias. Nevertheless, there are issues with patient adherence in the use of exposure therapy, including its self-directed formats. Technological advancements, as with smartphones, may improve adherence to self-directed exposure therapy, perhaps due to exposure stimuli being more readily accessible. Thus, there is a need to examine how presenting phobic material on a smartphone might promote increased adherence in conducting self-directed exposure. Additionally, exposure can incorporate phobic material from different perspectives (i.e., first-person or third-person), which is one factor that may impact treatment effectiveness. Participants (N = 36) were randomly assigned to a treatment or control condition, and completed a pre-assessment and then a post-assessment two weeks later. The assessment consisted of a multimodal approach (e.g., self-report, physiological response, and overt behavior). Participants in the treatment condition were instructed to watch a standard exposure video of a dental examination and prophylaxis three times daily for two weeks. One week of videos was shown in a first-person perspective and the same video was shown in a third-person perspective for one week. Results indicated that the smartphone-based stimuli were utilized by the participants, and that the treatment was acceptable to them. There was a significant interaction of time by condition for self-reported anxiety during a behavioral avoidance task. Participants in the treatment condition had significantly lower self-reported anxiety at the post-assessment compared to the pre-assessment, and no change in anxiety was found for the control group from pre- to post-assessment. A significant decrease in heart rate and trait anxiety was found from pre- to post-assessment for all participants. Results demonstrated the potential utility of smartphone-based self-directed exposure therapy for specific phobia