Spectral properties of one-dimensional Fermi systems after an interaction quench

We show that the single-particle spectral properties of gapless one-dimensional Fermi systems in the Luttinger liquid state reached at intermediate times after an abrupt quench of the two-particle interaction are highly indicative of the unusual nonequilibrium nature of this state. The line shapes of the momentum integrated and resolved spectral functions strongly differ from their ground state as well as finite temperature equilibrium counterparts. Using an energy resolution improved version of radio-frequency spectroscopy of quasi one-dimensional cold Fermi gases it should be possible to experimentally identify this nonequilibrium state by its pronounced spectral signatures.Comment: 5 pages, 3 figure

Transport in quasiperiodic interacting systems: from superdiffusion to subdiffusion

Using a combination of numerically exact and renormalization-group techniques we study the nonequilibrium transport of electrons in an one-dimensional interacting system subject to a quasiperiodic potential. For this purpose we calculate the growth of the mean-square displacement as well as the melting of domain walls. While the system is nonintegrable for all studied parameters, there is no on finite region default of parameters for which we observe diffusive transport. In particular, our model shows a rich dynamical behavior crossing over from superdiffusion to subdiffusion. We discuss the implications of our results for the general problem of many-body localization, with a particular emphasis on the rare region Griffiths picture of subdiffusion.Comment: 6 pages, 5 figures. A more detailed analysis of the dynamical exponents extraction and discussion of the relevant times. Adds a log-derivative for the FRG sectio

Thermal conductance of metallic atomic-size contacts: Phonon transport and Wiedemann-Franz law

Motivated by recent experiments [Science 355, 6330 (2017); Nat. Nanotechnol. 12, 430 (2017)], we present here an extensive theoretical analysis of the thermal conductance of atomic-size contacts made of three different metals, namely gold (Au), platinum (Pt) and aluminum (Al)

Mind the Future Gap: Introducing the FOD Framework for Future-Oriented Design

There are many uncertainties and ambiguities in the design of future-oriented artifacts. Societal and environmental developments are unclear; technologies not ready; target users not accessible. Nevertheless, designing future-oriented artifacts provides opportunities to either create radical innovations that present a competitive advantage, or to engage with relevant stakeholders in a speculative way. This paper provides a framework for developing, discussing, and evaluating future-oriented artifacts, which was developed based on literature and conceptual theorizing. It consists of a process model and a morphological box, outlining eight categories of relevance along with several options to choose from. Subsequently, we applied the framework to an existing future design project to illustrate its applicability. The framework spans the space of possible design and evaluation approaches and, hence, provides a guiding schema for researchers and practitioners to discuss the potentials and implications of design concepts for future-oriented artifacts

Designing the Future With the “Delphi Design Sprint”: Introducing a Novel Method for Design Science Research

This paper introduces a novel innovation method that focuses on the development of future-oriented artifacts. The “Delphi Design Sprint” combines two existing methods—the Delphi method and Design Sprints. The development of the method follows an action research approach and was tested and validated in a university-led design project involving a panel of 20 international experts. This paper introduces the method and describes exemplary results of the project’s outcome

A close-pair binary in a distant triple supermassive black-hole system

Galaxies are believed to evolve through merging, which should lead to multiple supermassive black holes in some. There are four known triple black hole systems, with the closest pair being 2.4 kiloparsecs apart (the third component is more distant at 3 kiloparsecs), which is far from the gravitational sphere of influence of a black hole with mass $\sim$10$^9$ M$_\odot$ (about 100 parsecs). Previous searches for compact black hole systems concluded that they were rare, with the tightest binary system having a separation of 7 parsecs. Here we report observations of a triple black hole system at redshift z=0.39, with the closest pair separated by $\sim$140 parsecs. The presence of the tight pair is imprinted onto the properties of the large-scale radio jets, as a rotationally-symmetric helical modulation, which provides a useful way to search for other tight pairs without needing extremely high resolution observations. As we found this tight pair after searching only six galaxies, we conclude that tight pairs are more common than hitherto believed, which is an important observational constraint for low-frequency gravitational wave experiments.Comment: 21 pages, 6 figures. Published online by Nature on 25 June 2014. Extremely minor differences with published version exis

The role of family functioning and self-esteem in the quality of life of adolescents referred for psychiatric services: a 3-year follow-up.

PurposeTo investigate, in adolescents referred for psychiatric services, the associations of initial self-esteem and family functioning with level and change of quality of life (QoL) over a 3-year period, over and above the effect of their emotional problems.MethodsOf 1648 eligible 13-18 years old patients attending the child and adolescent psychiatric clinic (CAP) at least once, 717 (54.8% females) were enrolled at baseline (a response rate of 43.5%). Self- and parent reports on the McMaster Family Assessment Device were obtained. Adolescents reported self-esteem on the Rosenberg Scale, and emotional problems on the Symptom Check List-5. Adolescents completed the Inventory of Life Quality in Children and Adolescents (ILC). After 3 years, 570 adolescents again completed the ILC, and for 418 adolescents parent information was available. The longitudinal analysis sample of 418 adolescents was representative of the baseline sample for age, gender, emotional problems, and QoL. We used modified growth-model analysis, adjusted for SES, age, gender and time of contact with CAP, where residual variances for ILC at baseline and follow-up were fixed to 0.ResultsA poorer family functioning at baseline, reported by parents, was significantly associated with worsening QoL during the 3 years follow-up period (p = 0.001).ConclusionsParents have important knowledge about their families that may reflect long-term influences on QoL development in adolescent psychiatric patients. Health care providers and policy makers should optimize treatment outcomes by addressing family functioning in adolescents with emotional problems

HDArray: Parallel Array Interface for Distributed Heterogeneous Devices

Heterogeneous clusters with nodes containing one or more accelerators, such as GPUs, have become common. While MPI provides a mechanism and management of interaddress space communication, and OpenCL provides a way to manage computation and communication within a process with access to heterogeneous computational resources, programmers are forced to write hybrid programs that manage the interaction of both of these systems. This paper describes an array programming interface that provides users with automatic or manual distributions of data and work. Using the distribution and information about what data is used and defined by kernels, communication among processes and among devices in a process is performed automatically. The interface provides a unified programming model to the user, thus simplifying program development

The preferentially magnified active nucleus in IRAS F10214+4724 - III. VLBI observations of the radio core

We report 1.7GHz very long baseline interferometry (VLBI) observations of IRAS F10214+4724, a lensed z = 2.3 obscured quasar with prodigious star formation. We detect what we argue to be the obscured active nucleus with an effective angular resolution of 1dex) and therefore distort our view of high-redshift, gravitationally lensed galaxies.Department of HE and Training approved lis