4,919 research outputs found
WavePacket: A Matlab package for numerical quantum dynamics. II: Open quantum systems, optimal control, and model reduction
WavePacket is an open-source program package for numeric simulations in
quantum dynamics. It can solve time-independent or time-dependent linear
Schr\"odinger and Liouville-von Neumann-equations in one or more dimensions.
Also coupled equations can be treated, which allows, e.g., to simulate
molecular quantum dynamics beyond the Born-Oppenheimer approximation.
Optionally accounting for the interaction with external electric fields within
the semi-classical dipole approximation, WavePacket can be used to simulate
experiments involving tailored light pulses in photo-induced physics or
chemistry. Being highly versatile and offering visualization of quantum
dynamics 'on the fly', WavePacket is well suited for teaching or research
projects in atomic, molecular and optical physics as well as in physical or
theoretical chemistry. Building on the previous Part I which dealt with closed
quantum systems and discrete variable representations, the present Part II
focuses on the dynamics of open quantum systems, with Lindblad operators
modeling dissipation and dephasing. This part also describes the WavePacket
function for optimal control of quantum dynamics, building on rapid
monotonically convergent iteration methods. Furthermore, two different
approaches to dimension reduction implemented in WavePacket are documented
here. In the first one, a balancing transformation based on the concepts of
controllability and observability Gramians is used to identify states that are
neither well controllable nor well observable. Those states are either
truncated or averaged out. In the other approach, the H2-error for a given
reduced dimensionality is minimized by H2 optimal model reduction techniques,
utilizing a bilinear iterative rational Krylov algorithm
The Uncontrolled Social Utility Hypothesis Revisited
The experiment disentangles communication and social effect in face-to-face communication. The results question the previous interpretation of communication effects in ultimatum bargaining, and suggest that separate processes, both of a strategic and of an affective-social nature induce cooperative outcomes.
Predictive accuracy of political stock markets: Empirical evidence from an European perspective
In a meta study of 25 political stock markets conducted in Germany in the last decade we analyze their predictive success. Although the predictions of political stock markets are highly correlated with the corresponding polls, the markets are able to aggregate additional information. One explanatory variable for variations in predictive success of the German stock markets relative to the polls is market efficiency. Even though the overall predictions of the political stock markets are quite reliable on the aggregate level we find systematic prediction errors on the contract level that can be attributed to the vote share size and to individual trader biases. --political stock markets,forecasting,market efficiency,proportional representation
Disclosing Conflict of Interest - Does Experience and Reputation Matter?
Disclosure of conflict of interest is currently seen as an effective tool for reducing threats to auditor independence. Cain, Loewenstein, and Moore (2005) provide evidence for perverse effects of disclosing conflict of interest. Using a controlled laboratory experiment, we replicate their finding that such a disclosure can cause an impairment of auditor independence. However, as subjects gain experience we find that these results revert and auditors give less biased advice. Our results imply that the perverse effects noted in the literature might be an artifact of an environment with inexperienced subjects and of less relevance for the audit environment where main actors are experienced. To the contrary, disclosure of conflict of interest can even improve auditor independence by fostering fairness. Furthermore, we find that disclosure of conflict of interests disturbs reputation building.
The Uncontrolled Social Utility Hypothesis Revisited
The experiment disentangles communication and social effect in face−to−face communication. The results question the previous interpretation of communication effects in ultimatum bargaining, and suggest that separate processes, both of a strategic and of an affective−social nature induce cooperative outcomes.
Non-market time and household well-being
A distinguishing feature among households is whether adult members work or not, since the employment status affects a household's available time for home activities. Using a survey method in two countries, Belgium and Germany, we provide household incomes that retain the level of well-being across different family types, distinguished by family size and employment status of adults. Our tests support that specialization in home production and childcare-time costs are important determinants of household well-being. Estimates of child costs relative to an adult are higher for households that are time-constrained (all adults in the household work), and also higher for poorer households. --household production,child costs,childcare,survey method
Asset Bubbles without Dividends - An Experiment
Bubbles in asset markets have been documented in numerous experimental studies. However, all experiments in which bubbles occur pay dividends after each trading day. In this paper we study whether bubbles can occur in markets without dividends. We investigate the role of two features that are present in real markets. (1) The mere possibility that some traders may have inside information, and (2) the option to communicate with other traders. We find that bubbles can indeed occur without dividends. Surprisingly, communication turns out to be counterproductive for bubble formation, whereas the possibility of inside information is, as expected, crucial.asset markets, bubbles, experiment, mirages, dividends
Properties of Equivalence Scales in Different Countries
Recent studies in high-income industrialized countries have shown that equivalence scales are income-dependent. We investigate whether this dependence also holds in poorer, services oriented countries, by considering the example of Cyprus. We also examine whether household economies of scale and relative children costs differ.
Non-Market Household Time and the cost of Children
A distinguishing feature among households is whether adult members work or not, since the occupational status of adults affects their available time for home activities. Using a survey method in two countries, Belgium and Germany, we provide household incomes that retain the level of well-being across different family types, distinguished by family size and occupational status of adults. Our tests support that childcare-time costs are important determinants of household well-being. Estimates of child costs relative to an adult are higher for households that are time-constrained (all adults in the household work). Moreover, we find supportive evidence for the hypothesis that, in two-adult households, there is a potential for within-household welfare gains from specialization in market- vs. domestic activities, especially childcare.
Nonmarket Household Time and the Cost of Children
Raising children demands a considerable amount of parental time, obliging working parents either to further reduce their leisure or to buy child-care services in the market. Parents may face additional opportunity costs upon deciding to participate in the labor market, but these are difficult to measure. Using a survey instrument in Belgium and Germany, we estimate the income compensation needed to maintain family well-being when adults work vs. when they do not enter the labor market. In both countries we find that full-time working parents face extra child costs and require higher labor-market-participation compensation compared to childless adults.equivalent income, household well-being, reservation wage, child costs, parental unemployment trap, survey method.
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