130 citations · 934 across the 27 of their papers we have counts for
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Thermal History of the Early Universe and Primordial Gravitational Waves from Induced Scalar Perturbations
Fazlollah Hajkarim, Jürgen Schaffner-Bielich
We study the induced primordial gravitational waves (GW) coming from the effect of scalar perturbation on the tensor perturbation at the second order of cosmological perturbation t…
Effects of the QCD Equation of State and Lepton Asymmetry on Primordial Gravitational Waves
Fazlollah Hajkarim, Jürgen Schaffner-Bielich, Stephan Wystub +1
Using the quantum chromodynamics (QCD) equation of state (EoS) from lattice calculations we investigate effects from QCD on primordial gravitational waves (PGWs) produced during th…
Primordial Gravitational Waves in Nonstandard Cosmologies
Nicolás Bernal, Fazlollah Hajkarim
Assuming that inflation is followed by a phase where the energy density of the Universe is dominated by a component with a general equation of state, we evaluate the spectrum of pr…