Search results for " Invariance"
showing 10 items of 219 documents
Spacetime correlators of perturbations in slow-roll de Sitter inflation
2014
Two-point correlators and self-correlators of primordial perturbations in quasi-de Sitter spacetime backgrounds are considered. For large separations two-point correlators exhibit nearly scale invariance, while for short distances self-correlators need standard renormalization. We study the deformation of two-point correlators to smoothly match the self-correlators at coincidence. The corresponding angular power spectrum is evaluated in the Sachs-Wolfe regime of low multipoles. Scale invariance is maintained, but the amplitude of $C_{\ell}$ could change in a non-trivial way.
Electric-magnetic duality and renormalization in curved spacetimes
2014
We point out that the duality symmetry of free electromagnetism does not hold in the quantum theory if an arbitrary classical gravitational background is present. The symmetry breaks in the process of renormalization, as also happens with conformal invariance. We show that a similar duality-anomaly appears for a massless scalar field in $1+1$ dimensions.
Psychometric Comparisons of Benevolent and Corrective Humor across 22 Countries: The Virtue Gap in Humor Goes International
2018
All authors: Sonja Heintz, Willibald Ruch, Tracey Platt, Dandan Pang, Hugo Carretero-Dios, Alberto Dionigi, Catalina Argüello Gutiérrez, Ingrid Brdar, Dorota Brzozowska, Hsueh-Chih Chen, Władysław Chłopicki, Matthew Collins, Róbert Ďurka, Najwa Y. El Yahfoufi, Angélica Quiroga-Garza, Robert B. Isler, Andrés Mendiburo-Seguel, TamilSelvan Ramis, Betül Saglam, Olga V. Shcherbakova, Kamlesh Singh, Ieva Stokenberga, Peter S. O. Wong and Jorge Torres-Marín.
Primordial power spectrum features in phenomenological descriptions of inflation
2016
We extend an alternative, phenomenological approach to inflation by means of an equation of state and a sound speed, both of them functions of the number of $e$-folds and four phenomenological parameters. This approach captures a number of possible inflationary models, including those with non-canonical kinetic terms or scale-dependent non-gaussianities. We perform Markov Chain Monte Carlo analyses using the latest cosmological publicly available measurements, which include Cosmic Microwave Background (CMB) data from the Planck satellite. Within this parametrization, we discard scale invariance with a significance of about $10\sigma$, and the running of the spectral index is constrained as …
Extending the sGLOH descriptor
2015
This paper proposes an extension of the sGLOH keypoint descriptor [3] which improves its robustness and discriminability. The sGLOH descriptor can handle discrete rotations by a cyclic shift of its elements thanks to its circular structure, but its performance can decrease when the keypoint relative rotation is in between two sGLOH discrete rotations. The proposed extension couples together two sGLOH descriptors for the same patch with different rotations in order to cope with this issue and it can be also applied straightly to the sCOr and sGOr matching strategies of sGLOH. Experimental results show a consistent improvement of the descriptor discriminability, while different setups can be …
Shift- and scale-invariant recognition of contour objects with logarithmic radial harmonic filters.
2008
The phase-only logarithmic radial harmonic (LRH) filter has been shown to be suitable for scale-invariant block object recognition. However, an important set of objects is the collection of contour functions that results from a digital edge extraction of the original block objects. These contour functions have a constant width that is independent of the scale of the original object. Therefore, since the energy of the contour objects decreases more slowly with the scale factor than does the energy of the block objects, the phase-only LRH filter has difficulties in the recognition tasks when these contour objects are used. We propose a modified LRH filter that permits the realization of a shi…
Rumination for innovation? : analyzing the longitudinal effects of work-related rumination on creativity at work and off-job recovery
2017
ABSTRACTWork-related rumination is not a single construct, but consists of a dimension associated with negative emotions or affect (affective rumination), and a dimension associated with reflective thinking and applying strategies to solve problems (problem-solving pondering). In this three-wave longitudinal study across two years (N = 630) we investigated whether the relationships between work-related rumination, off-job recovery, and creativity at work varied along the two dimensions of work-related rumination. In addition, we tested whether the relationships followed normal, reversed, or reciprocal causation. The results showed, first, that in a one-year perspective affective rumination,…
Factor Structure and Measurement Invariance Across Gender Groups of the 15-Item Geriatric Depression Scale Among Chinese Elders
2019
The 15-item Geriatric Depression Scale (GDS-15) is widely used to screen depression among elders. But the factor structure of the Chinese version GDS-15 remains unclear. This study was conducted to determine the best-fit factor structure of GDS-15 and to assess measurement invariance across gender groups in a sample of Chinese elders recruited from Mainland China (final sample N = 2428). The best-fit factor structure was examined by confirmatory factor analysis (CFA). Multigroup CFA was utilized to test the measurement invariance across genders of the factor structure. The results of CFA revealed that a three-factor model, including life satisfaction (four items), general depressive affect …
A cross-country examination of emotional eating, restrained eating and intuitive eating: Measurement Invariance across eight countries
2020
This study examined the measurement invariance of three scales that assessed emotional eating, restrained eating, and intuitive eating across eight countries (Australia, Belgium, Canada, China, Italy, Japan, Spain and the United States) in order to determine their suitability for cross-country body image research. A total of 6272 young adults took part in this study. Participants completed an online survey including the Emotional Eating subscale of the Three Factor Eating Questionnaire-Revised 21, the Restraint subscale of the Eating Disorder Examination Questionnaire, and the Reliance on Hunger and Satiety Cues subscale of The Intuitive Eating Scale-2. Multi-group confirmatory factor analy…
Bryant's Empathy Index: Structure and Measurement Invariance across Gender in a Sample of Primary School-Aged Children.
2016
AbstractThe purpose of this study was to examine the dimensional structure and measurement invariance of Bryant’s Index of Empathy for Children and Adolescents (IECA) (Bryant, 1982) across gender in a representative sample of primary school-aged children in Spain. The sample consisted of 2,050 children (50.80% girls), with a mean age of 9.80 years (SD = 1.24), recruited from 27 primary schools. Exploratory and confirmatory factor analyses were conducted. The model that presented the best fit indices was Lasa, Holgado, Carrasco, and del Barrio’s (2008) three-factor model: Understanding Feelings, Feelings of Sadness, and Tearful Reaction. The levels of internal consistency for the subscales r…