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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

It´s All Relative: Time and Space in Nabokov´s Lolita

Preston, Robert January 2013 (has links)
This essay offers a deconstructive approach to Nabokov´s Lolita. Critics have tended to treat space and time as distinct concepts in the novel: choosing to analyse the role of either one or the other, and even when considering both, examining them in isolation. It´s narrator, Humbert Humbert, however, implies that "time" and "spatial" terms are interchangeable in a way reminiscent of Einstein´s Theory of Relativity in which space-time is a continuum that is experienced relative to the individual observer´s own position in the universe. This essay therefore explores the possibility that Nabokov may have used Einstein´s concept of space-time relativity as a metaphor in Lolita. The essay looks first at the various ways in which the idea of relativity surfaces throughout the novel not just in relation to space and time, but also in its moral, cultural and historic forms. The roles of the Hour Glass Lake, Lolita´s sunglasses and Humbert´s car, three of the novel´s chief symbols, are then discussed in relation to its key elements: the notion of time dilation, the place of the observer and Humbert´s space-time bubble. It next concentrates on how the characters in the novel exemplify the roles of both observer and observed in a modern, self-centred and morally relativistic world. The final section argues that Humbert’s "madness" represents the most extreme consequence of his living in his own solipsistic bubble of space-time, or "dream vacuum" as he calls it.
122

Controlling atomic motion: from single particle classical mechanics to many body quantum dynamics

Hanssen, James Louis 28 August 2008 (has links)
Not available / text
123

Experiments with a Bose-Einstein condensate in a quasi-1D magnetic waveguide

Henderson, Kevin Christopher 28 August 2008 (has links)
Not available / text
124

New classes of exact solutions for charged perfect fluids.

Mthethwa, Thulani Richard. 28 March 2014 (has links)
We investigate techniques to generate new classes of exact solutions to the Einstein- Maxwell field equations which represent the gravitational field of charged perfect fluid spherically symmetric distributions of matter. Historically, a large number of solutions have been proposed but only a small number have been demonstrated to satisfy elementary conditions for physical acceptability. Firstly we examine the case of the constant density and constant electric field charged fluid sphere and show empirically that such configurations of matter are unlikely to exist as basic physical requirements are violated. We then make an ansatz relating the fluid's electric field intensity to one of the gravitational potentials thereby simplifying the system of partial differential equations. This prescription yields an algorithmic process to generate new classes of exact solutions. We present a number of new solutions and comment on their viability as stellar models. Graphical plots generated by symbolic software of the main dynamical and geometrical quantities verify that one of our models is suitable to represent a physically relevant distribution of charged matter in the form of a spherical shell. In particular, positive definiteness of energy density and pressure are guaranteed, a pressure free hypersurface denoting the boundary of the star exists, the sound speed is shown to be sub-luminal and the energy conditions are satisfied everywhere in the interior of the star. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2012.
125

A QUEST for BEC : an all optical alternative

Barrett, Murray Douglas 05 1900 (has links)
No description available.
126

Dynamics of Bose-Einstein Condensates in Josephson Junctions

Semple, Jaclyn 11 January 2011 (has links)
We numerically solve the Gross-Pitaevskii equation and the Bogoliubov de Gennes equations for a double well potential in order to model the dynamics of a Bose-Einstein condensate in a Josephson junction. First, the two dynamical regimes of the Josephson junction, that is, Josephson oscillations and self-trapping, are investigated under the application of a large sudden perturbation. It is found that the Josephson dynamics have a strong dependence on the strength of the interatomic interaction, and we observe the breakdown of the two-mode approximation. Second, we study the control of the dynamics through the use of a time-dependent, tilted double well potential. In the context of complete population transfer, the effect of the interactions on the adiabaticity and self-trapping is discussed in terms of a Landau-Zener-like model. We then explore the splitting of the condensate and the resulting dynamical behaviour by keeping the interaction strength constant, but changing the rate of the tilt sweep. Lastly, we examine the effect of the tilt sweep rate on the dynamics of population transfer. We observe a dependence of the self-trapping on the adiabaticity. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2011-01-10 16:31:43.127
127

Bose-Einstein Condensate Wavefunction Reconstruction Through Collisions with Optical Potentials

Ellenor, Christopher William 30 August 2011 (has links)
A new technique for the interferometric measurement of an atomic wavefunction is introduced theoretically, which is able to extract phase and amplitude information in a single measurement. I focus on the application of this technique to the single-particle wavefunction of a Bose condensed cloud of rubidium atoms. The technique differs from existing techniques mainly in its simplicity, as it requires only a single laser beam to be added to a typical Bose-Einstein condensation apparatus. A second novel aspect is the consideration of condensate collisions with an optical potential in the low-intensity limit where the potential barrier may be viewed as a phase mask. The technique is then demonstrated experimentally. A related effect, the transient enhancement of momentum during a collision, first predicted by JG Muga et al., has also been demonstrated. Finally, significant redesign and construction of an apparatus to produce condensates of 87Rb is documented. The main result of this work is the production of pure condensates of up to 150k atoms which can be repeated every 45s. A calibration technique is devised and demonstrated, whereby copies of the condensate are made, and the copies are used to reduce the centre-of-mass momentum uncertainty of the interacting cloud by a factor of five.
128

Bose-Einstein Condensate Wavefunction Reconstruction Through Collisions with Optical Potentials

Ellenor, Christopher William 30 August 2011 (has links)
A new technique for the interferometric measurement of an atomic wavefunction is introduced theoretically, which is able to extract phase and amplitude information in a single measurement. I focus on the application of this technique to the single-particle wavefunction of a Bose condensed cloud of rubidium atoms. The technique differs from existing techniques mainly in its simplicity, as it requires only a single laser beam to be added to a typical Bose-Einstein condensation apparatus. A second novel aspect is the consideration of condensate collisions with an optical potential in the low-intensity limit where the potential barrier may be viewed as a phase mask. The technique is then demonstrated experimentally. A related effect, the transient enhancement of momentum during a collision, first predicted by JG Muga et al., has also been demonstrated. Finally, significant redesign and construction of an apparatus to produce condensates of 87Rb is documented. The main result of this work is the production of pure condensates of up to 150k atoms which can be repeated every 45s. A calibration technique is devised and demonstrated, whereby copies of the condensate are made, and the copies are used to reduce the centre-of-mass momentum uncertainty of the interacting cloud by a factor of five.
129

New approaches to space-time singularities / by Susan M. Scott

Scott, Susan M. (Susan Marjorie) January 1991 (has links)
Includes bibliographical references / vi, 128 leaves ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 1992
130

Singular behavior in T² symmetric spacetimes with cosmological constant /

Clausen, Adam, January 2007 (has links)
Thesis (Ph. D.)--University of Oregon, 2007. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 95-98). Also available for download via the World Wide Web; free to University of Oregon users.

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