Effects of spatial noncommutativity on energy spectrum of a trapped Bose-Einstein condensate

In noncommutative space, we examine the problem of a noninteracting and harmonically trapped Bose-Einstein condensate, and derive a simple analytic expression for the effect of spatial noncommutativity on energy spectrum of the condensate. It indicates that the ground-state energy incorporating the spatial noncommutativity is reduced to a lower level, which depends upon the noncommutativity parameter $\theta$. The appeared gap between the noncommutative space and commutative one for the ground-state level of the condensate should be a signal of spatial noncommutativity.Comment: 7 pages; revtex

The Happer's puzzle degeneracies and Yangian

We find operators distinguishing the degenerate states for the Hamiltonian $H= x(K+{1/2})S_z +{\bf K}\cdot {\bf S}$ at $x=\pm 1$ that was given by Happer et al$^{[1,2]}$ to interpret the curious degeneracies of the Zeeman effect for condensed vapor of $^{87}$Rb. The operators obey Yangian commutation relations. We show that the curious degeneracies seem to verify the Yangian algebraic structure for quantum tensor space and are consistent with the representation theory of $Y(sl(2))$.Comment: 8 pages, Latex fil

ESSAYS ON MARKET INEFFICIENCIES ARISING FROM INFORMATION ASYMMETRY AND MARKET POWER

This dissertation comprises three chapters that empirically investigate various kinds of market inefficiencies arising from seller misbehaviors. The first two chapters focus on physicians\u27 overtreatment in healthcare markets. A standard reputation system falls short of effectively curbing overtreatment due to the credence-good nature of such a market: patients cannot tell whether a high-cost treatment recommendation (versus a less costly and complex treatment) is necessary even after the service is completed. In the first chapter, I propose a novel solution to reinstate the function of reputation by combining a reputation mechanism with patient search for second opinions. I conduct a laboratory experiment to test this new mechanism. In the second chapter, motivated by newly-emerged public information, the aggregate count of each type of treatment provided by a health provider, I experimentally investigate whether such information could reduce overtreatment and replace patients’ reliance on costly searches in repeated interactions. In the third chapter, the focus shifts to market power in wholesale electricity markets. In this study, my co-author and I utilize nuclear refueling outages as a test for the exercise of market power by energy suppliers in the New England market during the years 2016-2018

Role of quark-interchange processes in evolution of mesonic matter

We divide the cross section for a meson-meson reaction into three parts. The first part is for the quark-interchange process, the second for quark-antiquark annihilation processes and the third for resonant processes. Master rate equations are established to yield time dependence of fugacities of pions, rhos, kaons and vetor kaons. The equations include cross sections for inelastic scattering of pions, rhos, kaons and vector kaons. Cross sections for quark-interchange-induced reactions, that were obtained in a potential model, are parametrized for convenient use. The number densities of pion and rho (kaon and vector kaon) are altered by quark-interchange processes in equal magnitudes but opposite signs. The master rate equations combined with the hydrodynamic equations for longitudinal and transverse expansion are solved with many sets of initial meson fugacities. Quark-interchange processes are shown to be important in the contribution of the inelastic meson-meson scattering to evolution of mesonic matter.Comment: 28 pages, 1 figure, 8 table