192 citations · 2.3k across the 49 of their papers we have counts for
48 papers
Tachyonic particle production: quantum 2PI formalism with momentum exchanging collisions
Kimmo Kainulainen, Sami Nurmi, Olli Väisänen
Oscillating spacetime curvature can drive particle production during reheating, whose accurate modeling requires the use of non-perturbative out-of-equilibrium methods. Tachyonic i…
Stochastic Gravitational Waves from Modulated Reheating
Michele Benaco, Dimitrios Karamitros, Sami Nurmi +1
We investigate scalar-induced stochastic gravitational waves from adiabatic curvature perturbations sourced by a spectator field via the modulated reheating mechanism. We consider…
Tachyonic production of dark relics: classical lattice vs. quantum 2PI in Hartree truncation
Kimmo Kainulainen, Sami Nurmi, Olli Väisänen
We study the out-of-equilibrium production of non-minimally coupled self-interacting scalar dark matter during reheating using classical lattice simulations. The outcomes of the cl…
Primordial black holes from a curvaton scenario with strongly non-Gaussian perturbations
Andrew D. Gow, Tays Miranda, Sami Nurmi
We investigate the production of primordial black holes (PBHs) in a mixed inflaton-curvaton scenario with a quadratic curvaton potential, assuming the curvaton is in de Sitter equi…
Inflationary gravitational wave background as a tail effect
Niko Jokela, K. Kajantie, M. Laine +2
The free propagator of a massless mode in an expanding universe can be written as a sum of two terms, a lightcone and a tail part. The latter describes a subluminal (time-like) sig…
Tachyonic production of dark relics: a non-perturbative quantum study
Kimmo Kainulainen, Olli Koskivaara, Sami Nurmi
We study production of dark relics during reheating after the end of inflation in a system consisting of a non-minimally coupled spectator scalar field and the inflaton. We derive…