Collective excitations of BEC under anharmonic trap position jittering

Collective excitations of a Bose-Einstein condensate under periodic oscillations of a quadratic plus quartic trap position has been studied. A coupled set of variational equations is derived for the width and the condensate wave function center. Analytical expressions for the growth of oscillation amplitudes in the resonance case are derived. It is shown that jittering of an anharmonic trap position can cause double resonance of the BEC width and the center of mass oscillation in the wide range of the BEC parameters values. The predictions of variational approach are confirmed by full numerical simulations of the 1D GP equation.Comment: This paper contains a manuscript - SolAnJPB.tex and figures (fig1 - fig1a.eps and fig1b.eps, fig2 - fig2.eps, fig3 - fig3a.eps and fig3b.eps, fig4 - fig4a.eps and fig4b.eps). The manuscript has been prepared using LATEX2e with the iopart class and the figures in encapsulated PostScrip

Resonances in a trapped 3D Bose-Einstein condensate under periodically varying atomic scattering length

Nonlinear oscillations of a 3D radial symmetric Bose-Einstein condensate under periodic variation in time of the atomic scattering length have been studied analytically and numerically. The time-dependent variational approach is used for the analysis of the characteristics of nonlinear resonances in the oscillations of the condensate. The bistability in oscillations of the BEC width is invistigated. The dependence of the BEC collapse threshold on the drive amplitude and parameters of the condensate and trap is found. Predictions of the theory are confirmed by numerical simulations of the full Gross-Pitaevski equation.Comment: 17 pages, 10 figures, submitted to Journal of Physics

Images of resistance: A photonarrative enquiry into the meanings of personal artwork for people living with cancer

This study explored the meanings, inspirations and subjective significance of personal artwork created as a leisure activity by women living with cancer. A convenience sample of twelve women aged between 23-74 years participated in semi-structured interviews. Participants were living in various stages of the cancer trajectory, and engaged in several forms of visual art-making. They submitted examples of their artwork by photograph and then participated in semi-structured interviews. From a phenomenological analysis, the authors inferred a number of themes. Participants perceived a few pieces, made during chemotherapy, as expressing deeper feelings about cancer in symbolic terms. More prevalent in participants’ accounts were references to their artwork as a sensuous pleasure, and its confirmation of their ongoing capability, personal continuity and social connectedness. Participants acknowledged ongoing loss and difficulties related to cancer. However, each piece of art offered a measure of resistance against the psychologically and socially disruptive effects of cancer. The pre-interview photography activity was helpful for empowering participants in the interview, and for stimulating detailed memories and associations