黄志琦

After early-universe inflation, the inflaton decays into other fields via a reheating process. If the decay begins with a preheating stage, where the fluctuations of coupled fields are exponentially excited by parametric resonance, the energy transfer can be much more efficient and possibly producing observable signatures to reveal exciting new physics beyond the standard model. In 2009 my collaborators and I proposed that, if the equation of the state of the multi-field system is modulated by the background field values, large-scale metric fluctuations can indeed be generated from the modulated preheating process. Continuing on this topic, I will discuss my recent work on the impact of modulated preheating on the formation of high-redshift mini-haloes, which is a key ingredient for the direct-collapse scenario of supermassive black holes.