(Re-)Inventing the Relativistic Wheel: Gravity, Cosets, and Spinning Objects

Space-time symmetries are a crucial ingredient of any theoretical model in physics. Unlike internal symmetries, which may or may not be gauged and/or spontaneously broken, space-time symmetries do not admit any ambiguity: they are gauged by gravity, and any conceivable physical system (other than the vacuum) is bound to break at least some of them. Motivated by this observation, we study how to couple gravity with the Goldstone fields that non-linearly realize spontaneously broken space-time symmetries. This can be done in complete generality by weakly gauging the Poincare symmetry group in the context of the coset construction. To illustrate the power of this method, we consider three kinds of physical systems coupled to gravity: superfluids, relativistic membranes embedded in a higher dimensional space, and rotating point-like objects. This last system is of particular importance as it can be used to model spinning astrophysical objects like neutron stars and black holes. Our approach provides a systematic and unambiguous parametrization of the degrees of freedom of these systems.Comment: 30 page

Interrupted Meal, by Heinrich von Rustige.

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Design and Synthesis of Heterocycle‐Fused Enediyne Prodrugs Activable at Will

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Profiling residential water users’ routines by eigenbehavior modelling

Developing effective demand-side management strategies is essential to meet future residential water demands, pursue water conservation, and reduce the costs for water utilities. The effectiveness of water demand management strategies relies on our understanding of water consumers’ behavior and their consumption habits and routines, which can be monitored through the deployment of smart metering technologies and the adoption of data analytics and machine learning techniques. This work contributes a novel modeling procedure, based on a combination of clustering and principal component analysis, which allows performing water users’ segmentation on the basis of their eigenbehaviors (i.e., recurrent water consumption behaviors) automatically identified from smart metered consumption data. The approach is tested against a dataset of smart metered water consumption data from 175 households in the municipality of Tegna (CH). Numerical results demonstrate the potential of the method for identifying typical profiles of water consumption, which constitute essential information to support residential water demand management

Psychological flexibility and ostracism: Experiential avoidance rather than cognitive fusion moderates distress from perceived ostracism over time

Psychological inflexibility has been found to moderate psychological distress following perceived ostracism. Two component processes of psychological inflexibility, experiential avoidance and cognitive fusion, are considered key in exacerbating general emotional distress. The present study (n = 286) examined whether both experiential avoidance and cognitive fusion moderate distress from perceived ostracism or whether one of these processes alone underpins the moderation effect of psychological inflexibility. In a structural equation model analysis, when accounting for both factors, experiential avoidance moderated distress from perceived ostracism alone. Thus, it seems that experiential avoidance is a key driver underlying emotional regulation of psychological distress in the context of perceived ostracism

Numerical solutions to linear transfer problems of polarized radiation III. Parallel preconditioned Krylov solver tailored for modeling PRD effects

Context. The polarization signals produced by the scattering of anistropic radiation in strong resonance lines encode important information about the elusive magnetic fields in the outer layers of the solar atmosphere. An accurate modeling of these signals is a very challenging problem from the computational point of view, in particular when partial frequency redistribution (PRD) effects in scattering processes are accounted for with a general angle-dependent treatment. Aims. We aim at solving the radiative transfer problem for polarized radiation in nonlocal thermodynamic equilibrium conditions, taking angle-dependent PRD effects into account. The problem is formulated for a two-level atomic model in the presence of arbitrary magnetic and bulk velocity fields. The polarization produced by scattering processes and the Zeeman effect is considered. Methods. The proposed solution strategy is based on an algebraic formulation of the problem and relies on a convenient physical assumption, which allows its linearization. We applied a nested matrix-free GMRES iterative method. Effective preconditioning is obtained in a multifidelity framework by considering the light-weight description of scattering processes in the limit of complete frequency redistribution (CRD). Results. Numerical experiments for a one-dimensional (1D) atmospheric model show near optimal strong and weak scaling of the proposed CRD-preconditioned GMRES method, which converges in few iterations, independently of the discretization parameters. A suitable parallelization strategy and high-performance computing tools lead to competitive run times, providing accurate solutions in a few minutes. Conclusions. The proposed solution strategy allows the fast systematic modeling of the scattering polarization signals of strong resonance lines, taking angle-dependent PRD effects into account together with the impact of arbitrary magnetic and bulk velocity fields. Almost optimal strong and weak scaling results suggest that this strategy is applicable to realistic 3D models. Moreover, the proposed strategy is general, and applications to more complex atomic models are possible

Chemo-enzymatic synthesis of new resveratrol-related dimers containing the benzo[b]furan framework and evaluation of their radical scavenger activities

The chemo-enzymatic synthesis and the evaluation of radical scavenger performance of resveratrolrelated dimers with antioxidative power have been investigated. The dimeric compounds, containing the benzo[b]furan framework, were prepared via an oxidative dimerization catalyzed by a laccase from Trametes versicolor, followed by a treatment with the organic oxidant DDQ. This methodology can be useful for the synthesis of various 2,3-diarylbenzo[b]furans derivates, a class of compound that exhibits a wide range of biological activities

A Thorough Study on the Photoisomerization of Ferulic Acid Derivatives

AbstractA thorough study on the (E) to (Z) photoisomerization of ferulic acid derivatives (esters, amides of all types, and ketones) was carried out. At the photostationary state, only aliphatic or benzylic tertiary amides reach a nearly complete conversion of (E) isomers into the (Z) ones, whereas for esters, primary and secondary amides or aromatic tertiary amides mixtures of (Z)/(E) ranging from 7 : 93 to 72 : 28 are observed. Ketones show rather limited photoisomerization. However, (Z) ketones may be obtained by the reaction of organometal compounds with an isomerized (Z) Weinreb amide