Compact, charged boson stars and shells in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="double-struck">C</mml:mi><mml:msup><mml:mi>P</mml:mi><mml:mi>N</mml:mi></mml:msup></mml:math> gravitating nonlinear sigma model
Physical review. D/Physical review. D.