Dark matter from a classically scale-invariant<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>S</mml:mi><mml:mi>U</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mn>3</mml:mn><mml:msub><mml:mo stretchy="false">)</mml:mo><mml:mi>X</mml:mi></mml:msub></mml:math>
Physical review. D/Physical review. D.