378 citations · 2.1k across the 25 of their papers we have counts for
55 papers
Freeze-in at stronger coupling
Catarina Cosme, Francesco Costa, Oleg Lebedev
Predictivity of many non-thermal dark matter (DM) models is marred by the gravitational production background. This problem is ameliorated in models with lower reheating temperatur…
On unitarity in singlet inflation with a non-minimal coupling to gravity
Oleg Lebedev, Yann Mambrini, Jong-Hyun Yoon
We study inflationary models based on a non-minimal coupling of a singlet scalar to gravity, focussing on the preheating dynamics and the unitarity issues in this regime. If the sc…
Sterile neutrino dark matter: relativistic freeze-out
Oleg Lebedev, Takashi Toma
Long-lived sterile neutrinos can play the role of dark matter. We consider the possibility that such neutrinos form a thermal bath with a singlet scalar, while not being in thermal…
Dark matter production via a non-minimal coupling to gravity
Oleg Lebedev, Timofey Solomko, Jong-Hyun Yoon
We study postinflationary scalar dark matter production via its non-minimal coupling to gravity. During the inflaton oscillation epoch, dark matter is produced resonantly for a suf…
Scalar overproduction in standard cosmology and predictivity of non-thermal dark matter
Oleg Lebedev
Stable scalars can be copiously produced in the Early Universe even if they have no coupling to other fields. We study production of such scalars during and after (high scale) infl…
On gravitational preheating
Oleg Lebedev, Jong-Hyun Yoon
We consider dark matter production during the inflaton oscillation epoch. It is conceivable that renormalizable interactions between dark matter and inflaton may be negligible. In…