scholarly journals Matching theory to characterize sound emission during vortex reconnection in quantum fluids

2020 ◽  
Vol 5 (10) ◽  
Author(s):  
Davide Proment ◽  
Giorgio Krstulovic
Keyword(s):  
Quantum Fluids ◽  
Matching Theory ◽  
Sound Emission ◽  
Vortex Reconnection

scholarly journals Vortex reconnections in classical and quantum fluids

SeMA Journal ◽  
2021 ◽  
Author(s):  
Alberto Enciso ◽  
Daniel Peralta-Salas
Keyword(s):  
Stokes Equations ◽  
Quantum Fluids ◽  
Navier Stokes ◽  
Pitaevskii Equation ◽  
Global Approximation ◽  
Rigorous Results ◽  
Navier Stokes Equations ◽  
Localization Principle ◽  
Global Smooth Solutions ◽  
Vortex Reconnection

AbstractWe review recent rigorous results on the phenomenon of vortex reconnection in classical and quantum fluids. In the context of the Navier–Stokes equations in $$\mathbb {T}^3$$ T 3 we show the existence of global smooth solutions that exhibit creation and destruction of vortex lines of arbitrarily complicated topologies. Concerning quantum fluids, we prove that for any initial and final configurations of quantum vortices, and any way of transforming one into the other, there is an initial condition whose associated solution to the Gross–Pitaevskii equation realizes this specific vortex reconnection scenario. Key to prove these results is an inverse localization principle for Beltrami fields and a global approximation theorem for the linear Schrödinger equation.

Hydrodynamic instability and shear layer effect on the sound emission of a turbulent jet flame

2015 ◽  
Author(s):  
Stephan Schlimpert ◽  
Seong Ryong Koh ◽  
Antje Feldhusen ◽  
Benedikt Roidl ◽  
Matthias H. Meinke ◽  
...  
Keyword(s):  
Shear Layer ◽  
Hydrodynamic Instability ◽  
Turbulent Jet ◽  
Sound Emission ◽  
Jet Flame ◽  
Layer Effect

Reforming the Labour Market in Good and Bad Times

2018 ◽  
Author(s):  
Britta Gehrke ◽  
Enzo Weber
Keyword(s):  
Time Series ◽  
Business Cycle ◽  
Labour Market ◽  
Markov Switching ◽  
Matching Theory ◽  
Market Reforms ◽  
Structural Reforms ◽  
Labour Market Reforms ◽  
Short Run ◽  
The Business Cycle

This chapter discusses how the effects of structural labour market reforms depend on whether the economy is in expansion or recession. Based on an empirical time series model with Markov switching that draws on search and matching theory, we propose a novel identification of reform outcomes and distinguish the effects of structural reforms that increase the flexibility of the labour market in distinct phases of the business cycle. We find in applications to Germany and Spain that reforms which are implemented in recessions have weaker expansionary effects in the short run. For policymakers, these results emphasize the costs of introducing labour market reforms in recessions.

scholarly journals ON THE CONVERGENCE RATE OF POTENTIALS OF BRENIER MAPS

2021 ◽  
pp. 1-37
Author(s):  
Florian F. Gunsilius
Keyword(s):  
Convergence Rate ◽  
Poincaré Inequality ◽  
Optimal Transportation ◽  
Matching Theory ◽  
Economic Research ◽  
Poincare Inequality ◽  
Optimal Transportation Problem ◽  
Minimax Rate ◽  
The Cost ◽  
Kantorovich Problem

The theory of optimal transportation has experienced a sharp increase in interest in many areas of economic research such as optimal matching theory and econometric identification. A particularly valuable tool, due to its convenient representation as the gradient of a convex function, has been the Brenier map: the matching obtained as the optimizer of the Monge–Kantorovich optimal transportation problem with the euclidean distance as the cost function. Despite its popularity, the statistical properties of the Brenier map have yet to be fully established, which impedes its practical use for estimation and inference. This article takes a first step in this direction by deriving a convergence rate for the simple plug-in estimator of the potential of the Brenier map via the semi-dual Monge–Kantorovich problem. Relying on classical results for the convergence of smoothed empirical processes, it is shown that this plug-in estimator converges in standard deviation to its population counterpart under the minimax rate of convergence of kernel density estimators if one of the probability measures satisfies the Poincaré inequality. Under a normalization of the potential, the result extends to convergence in the $L^2$ norm, while the Poincaré inequality is automatically satisfied. The main mathematical contribution of this article is an analysis of the second variation of the semi-dual Monge–Kantorovich problem, which is of independent interest.

The Effect of Under- and Over-Benefited Support Gaps on Hurt Feelings, Esteem, and Relationships

2015 ◽  
Vol 46 (6) ◽  
pp. 785-810 ◽  
Author(s):  
Rachel M. McLaren ◽  
Andrew C. High
Keyword(s):  
Matching Theory ◽  
Informational Support ◽  
Negative Outcomes ◽  
Supportive Communication ◽  
Optimal Matching ◽  
Network Support ◽  
Different Types ◽  
Hurt Feelings ◽  
Tangible Support

Although the supportive communication people receive from others during stressful times can be helpful, it can also result in negative outcomes. One explanation for these different effects might be how closely the support people receive matches their desires. This study extends optimal matching theory and examines how the discrepancy between the support people want and what they receive (called support gaps) corresponds with hurt feelings, perceived negative relational consequences, and esteem improvement. People can either receive less support than the desire (i.e., be under-benefited) or receive more support than they desire (i.e., be over-benefited), and these different types of support gaps produce distinct patterns of results. Specifically, action-facilitating support, which includes informational and tangible support, and nurturant support, which includes emotional, esteem, and network support, were studied. Results showed that being over-benefited in informational support and being under-benefited in emotional and esteem support is hurtful, and hurt corresponded with negative relational consequences and reduced esteem improvement. Implications for research on support gaps and hurt feelings are discussed.

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