  We investigate the effects of ellipticity-induced curvature on atomic
Bose-Einstein condensates confined in quasi-one-dimensional closed-loop
waveguides. Our theoretical study reveals intriguing phenomena arising from the
interplay between curvature and interactions. Density modulations are observed
in regions of high curvature, but these modulations are suppressed by strong
repulsive interactions. Additionally, we observe phase accumulation in regions
with the lowest curvature when the waveguide with persistent current is
squeezed. Furthermore, waveguides hosting persistent currents exhibit dynamic
transformations between states with different angular momenta. These findings
provide insights into the behavior of atomic condensates in curved waveguides,
with implications for fundamental physics and quantum technologies. The
interplay between curvature and interactions offers opportunities for exploring
novel quantum phenomena and engineering quantum states in confined geometries.
