4,527 research outputs found
The Schr\"odinger-Langevin equation with and without thermal fluctuations
The Schr\"odinger-Langevin (SL) equation is considered as an effective open
quantum system formalism suitable for phenomenological applications involving a
quantum subsystem interacting with a thermal bath. We focus on two open issues
relative to its solutions: the stationarity of the excited states of the
non-interacting subsystem when one considers the dissipation only and the
thermal relaxation toward asymptotic distributions with the additional
stochastic term. We first show that a proper application of the Madelung/polar
transformation of the wave function leads to a non zero damping of the excited
states of the quantum subsystem. We then study analytically and numerically the
SL equation ability to bring a quantum subsystem to the thermal equilibrium of
statistical mechanics. To do so, concepts about statistical mixed states and
quantum noises are discussed and a detailed analysis is carried with two kinds
of noise and potential. We show that within our assumptions the use of the SL
equation as an effective open quantum system formalism is possible and discuss
some of its limitations.Comment: 38 pages, 31 figure
Semi-classical approach to suppression in high energy heavy-ion collisions
We study the heavy quark/antiquark pair dynamics in strongly-coupled quark
gluon plasma. A semi-classical approach, based on the Wigner distribution and
Langevin dynamics, is applied to a color screened pair, in a
hydrodynamically cooling fireball, to evaluate the total suppression
at both RHIC and LHC energies. Although its limitation is observed, this
approach results to a suppression of around 0.30 at RHIC and 0.25 at
LHC.Comment: 4 pages, 6 figures, Proceeding for International Conference on
Strangeness in Quark Matter 2013 (SQM 2013) at Birmingha
Impact of Regulatory Agencies on the Efficiency of Publicly-Owned Utilities
We compare the economic efficiency of a publicly-owned utility directly controlled by the government with a publicly-owned utility regulated by a public utility commission (PUC). Regulation by a PUC is modelled as a Nash equilibrium of a game between two principals, the government and the PUC, each of them having control over a subset of decision variables determining the utility performance. A utility manager, who has private information over a productivity parameter, is the agent. Comparisons of both regulatory regimes are made with respect to output, choice of inputs, manager's information rent and firm's profit. Reasons for which the government should prefer one regulatory regime over the other are discussed. The recent regulatory reform of electricity markets in the province of Quebec (Canada) provides an illustration of the model.Regulation, Public Enterprises
International Competition between Public or Mixed Enterprises
We develop a model in which two firms from different countries compete on each other domestic market. Each firm is jointly owned by the residents and the government of its country. The extent of the government's stake in the public enterprise is endogenous and it determines the weight given to domestic consumers' surplus in the firm's payoff function. We show that the choice of each government's stake depends on a trade-off between allocative efficiency on the domestic market and profitability of foreign markets. We also highlight the fact that the government's stake in one country has an impact on firms' behavior in both countries.Regulation, public enterprises, duopoly
International Competition Between Public or Mixed Enterprises
We develop a model in which two firms from different countries compete on each other domestic market. Each firms is jointly owned by the residents and the government of its country. The extent of the government's stake in the public enterprise is endogenous and it determines the weight given the domestic consumers' surplus inithe firm's payoff function. We show that the choice of each government's stake depends on a trade-off between allocative efficiency on the domestic market and profitability of foreign markets. We also highlight the fact that the government's stake in on country has an impact of firms' behavior in both countries.Regulation, Public Enterprises, Duopoly
The present status of the teacher-training curriculum for men in health and physical education in Negro institutions of higher learning
Thesis (Ed.M.)--Boston University, 1948. This item was digitized by the Internet Archive
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