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SUMMARY:HiDDeN webinar: Reflections on Bubble Walls
DTSTART;VALUE=DATE-TIME:20230131T150000Z
DTEND;VALUE=DATE-TIME:20230131T160000Z
DTSTAMP;VALUE=DATE-TIME:20260429T102444Z
UID:indico-event-6936@indico.ific.uv.es
DESCRIPTION:We discuss the dynamics of expanding bubble walls in the prese
 nce of massive dark photons whose mass changes as they cross the wall. For
  sufficiently thin walls\, we show that there exists a transient kinematic
  regime characterized by a constant reflection probability of longitudinal
  -- but not transverse -- modes. This effect can have important implicatio
 ns for the dynamics of expanding vacuum bubbles in the early Universe. Mos
 t notably\, it leads to a new source of pressure on the expanding interfac
 e\, featuring a non-monotonic dependence on the γ-factor of the bubble w
 alls and reaching a peak at intermediate γ-factors that we dub Maximum D
 ynamic Pressure. When this pressure is large enough to halt the accelerati
 on of the bubble walls\, the difference in vacuum energy densities goes in
 to making a fraction of the dark photons relativistic\, turning them into 
 dark radiation. If the dark radiation remains relativistic until late time
 s\, an observable contribution to ΔN is possible for phase transitions
  with strength α ∼ 0.01 - 0.1.\n\nhttps://indico.ific.uv.es/event/69
 36/
LOCATION:& retransmitted from IFIC seminar room online
URL:https://indico.ific.uv.es/event/6936/
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