Thermodynamic and superfluid behavior of a trapped Bose gas

We study the properties of magnetically trapped atomic Bose gases with both negative and positive scattering lengths. We present theoretical results for the temperature dependence of the condensate fraction and for other quantities characterizing the thermodynamics of the trapped gas. We investigate the structure of the elementary excitations, including quantized vortices. We explore the behavior of the condensate wave function near the boundary with possible application to Josephson-type effects.