Leptogenesis with perturbations in type-II and type-III seesaw models

Density perturbations have recently been shown to lead to a novel effect in the freeze-out of heavy particles called "acoustically driven freeze-out." This leads to an enhancement in the yield in standard leptogenesis. We extend this calculation to include <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>2</mml:mn> <mml:mo>→</mml:mo> <mml:mn>2</mml:mn></mml:mrow> </mml:math> washout processes in type-I leptogenesis and the Sommerfeld-enhanced <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>2</mml:mn> <mml:mo>→</mml:mo> <mml:mn>2</mml:mn></mml:mrow> </mml:math> gauge annihilations in type-II and type-III leptogenesis. These CP conserving gauge annihilations suppress the yield of heavy particles sourcing the asymmetry. We show the acoustically driven freeze-out leads to novel enhancements in the baryon asymmetry in type-II and type-III leptogenesis, already in the weak washout regime, in contrast with type-I leptogenesis.