Non-KPZ modes in two-species driven diffusive systems

Using mode coupling theory and dynamical Monte-Carlo simulations we investigate the scaling behaviour of the dynamical structure function of a two-species asymmetric simple exclusion process, consisting of two coupled single-lane asymmetric simple exclusion processes. We demonstrate the appearence of a superdiffusive mode with dynamical exponent $z=5/3$ in the density fluctuations, along with a KPZ mode with $z=3/2$ and argue that this phenomenon is generic for short-ranged driven diffusive systems with more than one conserved density. When the dynamics is symmetric under the interchange of the two lanes a diffusive mode with $z=2$ appears instead of the non-KPZ superdiffusive mode.Comment: 5 pages, 7 figure

Fibonacci family of dynamical universality classes

Universality is a well-established central concept of equilibrium physics. However, in systems far away from equilibrium a deeper understanding of its underlying principles is still lacking. Up to now, a few classes have been identified. Besides the diffusive universality class with dynamical exponent $z=2$ another prominent example is the superdiffusive Kardar-Parisi-Zhang (KPZ) class with $z=3/2$. It appears e.g. in low-dimensional dynamical phenomena far from thermal equilibrium which exhibit some conservation law. Here we show that both classes are only part of an infinite discrete family of non-equilibrium universality classes. Remarkably their dynamical exponents $z_\alpha$ are given by ratios of neighbouring Fibonacci numbers, starting with either $z_1=3/2$ (if a KPZ mode exist) or $z_1=2$ (if a diffusive mode is present). If neither a diffusive nor a KPZ mode are present, all dynamical modes have the Golden Mean $z=(1+\sqrt{5})/2$ as dynamical exponent. The universal scaling functions of these Fibonacci modes are asymmetric L\'evy distributions which are completely fixed by the macroscopic current-density relation and compressibility matrix of the system and hence accessible to experimental measurement.Comment: 8 pages, 5 Figs (2 Figure revised, one new Figure added), revised introductio

Exact scaling solution of the mode coupling equations for non-linear fluctuating hydrodynamics in one dimension

We obtain the exact solution of the one-loop mode-coupling equations for the dynamical structure function in the framework of non-linear fluctuating hydrodynamics in one space dimension for the strictly hyperbolic case where all characteristic velocities are different. All solutions are characterized by dynamical exponents which are Kepler ratios of consecutive Fibonacci numbers, which includes the golden mean as a limiting case. The scaling form of all higher Fibonacci modes are asymmetric L\'evy-distributions. Thus a hierarchy of new dynamical universality classes is established. We also compute the precise numerical value of the Pr\"ahofer-Spohn scaling constant to which scaling functions obtained from mode coupling theory are sensitive.Comment: PACS classification: \pacs{05.60.Cd, 05.20.Jj, 05.70.Ln, 47.10.-g

Keeping the kids home : Increasing concern for others in times of crisis

During the COVID-19 pandemic, social consequences in day-to-day decisions might not have been salient to the decider and thus egoistic. How can prosocial intentions be increased? In an experimental vignette study with N = 206, we compared the likelihood that parents send sick children to kindergarten after four interventions (general information about COVID-19, empathy, reflection of consequences via mental simulation, and control group). Independent of the intervention, empathic concern with individuals who were affected by COVID-19 and the salience of social consequences were high. The reported likelihood of sending a sick child to kindergarten was somewhat reduced in the control group and even more reduced in the reflection and empathy group, but not in the information group

Understanding the Motives for Terrorism - Does it Have an Effect on Psychological Reactions? A Replication and Extension

The collective communication model of terrorism (CCMT) proposes that understanding terrorists' motives influences appraisal (threat perception and emotional well-being) and reaction to terrorism (intention to retaliate). Fischer et al. (2011) presented evidence from two experiments for the assumption that understanding motives of terrorism influences appraisal. The present preregistered experiment aimed to replicate their second experiment, validate the measures they used, and also test the second proposition of the CCMT. Ensuring sufficient power for multiple tests and the given effect size, we collected data from 188 participants. The findings by Fischer et al. (2011) were partly replicated, but the comparison of the original effect sizes and the effect sizes from the replication attempt does not provide convincing evidence for the hypothesis that understanding the motives for terrorism reduces the perceived threat or negative emotional impact of acts of terrorism. Correlations with other risk-perception measures call into question the validity of the items used to assess perceived threat. Results suggest that understanding the motives for terrorism may influence whether the targeted populations want to retaliate

Ensemble-induced strong light-matter coupling of a single quantum emitter

We discuss a technique to strongly couple a single target quantum emitter to a cavity mode, which is enabled by virtual excitations of a nearby mesoscopic ensemble of emitters. A collective coupling of the latter to both the cavity and the target emitter induces strong photon non-linearities in addition to polariton formation, in contrast to common schemes for ensemble strong coupling. We demonstrate that strong coupling at the level of a single emitter can be engineered via coherent and dissipative dipolar interactions with the ensemble, and provide realistic parameters for a possible implementation with SiV$^{-}$ defects in diamond. Our scheme can find applications, amongst others, in quantum information processing or in the field of cavity-assisted quantum chemistry.Comment: 13 pages, 6 figures; substantially revised manuscript; see arXiv:1912.12703 for mathematical derivation

Cavity-assisted mesoscopic transport of fermions: Coherent and dissipative dynamics

We study the interplay between charge transport and light-matter interactions in a confined geometry, by considering an open, mesoscopic chain of two-orbital systems resonantly coupled to a single bosonic mode close to its vacuum state. We introduce and benchmark different methods based on self-consistent solutions of non-equilibrium Green's functions and numerical simulations of the quantum master equation, and derive both analytical and numerical results. It is shown that in the dissipative regime where the cavity photon decay rate is the largest parameter, the light-matter coupling is responsible for a steady-state current enhancement scaling with the cooperativity parameter. We further identify different regimes of interest depending on the ratio between the cavity decay rate and the electronic bandwidth. Considering the situation where the lower band has a vanishing bandwidth, we show that for a high-finesse cavity, the properties of the resonant Bloch state in the upper band are transfered to the lower one, giving rise to a delocalized state along the chain. Conversely, in the dissipative regime with low cavity quality factors, we find that the current enhancement is due to a collective decay of populations from the upper to the lower band.Comment: 52 pages, 11 figure

Self-interest or joint welfare? Person and situation factors in interpersonal decisions about time

While previous research on interpersonal decisions has focused on individual differences or situational determinants, in this paper, we looked at the interplay of situation and personality in decisions that are characterized by a conflict between self-interest and joint welfare. In an online experiment, 185 participants made decisions about the allocation of their own work time and the work time of another anonymous participant. Agency and uncertainty were manipulated between subjects, and social value orientation as well as dispositional envy were assessed. Participants chose between an option that maximized participants' joint welfare and an option that maximized personal payoffs. The results pointed to an interaction between personality and situational forces: Uncertainty moderated the effect of social value orientation, and agency moderated the effect of envy on decisions. Taken together, the results provide evidence that the effect of individual differences in interpersonal decisions depends on the situation. Implications for team work are discussed in situations where a group potentially benefits disproportionally more from an individual's relatively higher effort than the individual who exerts the effort

Correcting wealth survey data for the missing rich: The case of Austria

It is a well-known criticism that due to its exponential distribution, survey data on wealth is hardly reliable when it comes to analyzing the richest parts of society. This paper addresses this criticism using Austrian data from the Household Finance and Consumption Survey (HFCS). In doing so we apply the assumption of a Pareto distribution to obtain estimates for the number of households possessing a net wealth greater than four million Euros as well as their aggregate wealth holdings. Thereby, we identify suitable parameter combinations by using a series of maximum-likelihood estimates and appropriate goodness-of-fit tests to avoid arbitrariness with respect to the fitting of the Pareto-Distribution. Our results suggest that the alleged non-observation bias is considerable, accounting for about one quarter of total net wealth. The method developed in this paper can easily be applied to other countries where survey data on wealth are available

Correcting for the missing rich: An application to Wealth Survey Data

It is a well-known criticism that if the distribution of wealth is highly concentrated, survey data are hardly reliable when it comes to analyzing the richest parts of society. This paper addresses this criticism by providing a general rationale of the underlying methodological problem as well as by proposing a specific methodological approach tailored to correcting the arising bias. We illustrate the latter approach by using Austrian data from the Household Finance and Consumption Survey. Specifically, we identify suitable parameter combinations by using a series of maximum-likelihood estimates and appropriate goodness-of-fit tests to avoid arbitrariness with respect to the fitting of the Pareto distribution. Our results suggest that the alleged non-observation bias is considerable, accounting for about one quarter of total net wealth in the case of Austria. The method developed in this paper can easily be applied to other countries where survey data on wealth are available