activity
20242026
collaborators

6 papers

hep-ph2026

Warm fermionic dark matter from freeze-in at stronger coupling

Duarte Feiteira, Vinícius Oliveira

We study warm fermionic dark matter (DM) in the framework of freeze-in at stronger coupling, in the minimal Higgs portal scenario. The reheating temperature is taken to be low, so…

hep-ph2026

Warm dark matter from freeze-in at stronger coupling

Duarte Feiteira, Oleg Lebedev, Vinícius Oliveira

We study warm Higgs portal dark matter (DM) in the framework of freeze-in at stronger coupling. This scenario assumes that the Standard Model thermal bath temperature has always be…

gr-qc2026

Recursive Penrose processes in electrically charged black hole spacetimes: Backreaction and energy extraction

Duarte Feiteira, José P. S. Lemos, Oleg B. Zaslavskii

We study a recursive Penrose process and the energy extraction for the decay of electrically charged particles in a Reissner-Nordström black hole spacetime with anti-de Sitter (Ad…

hep-ph2026

Quark, lepton and right-handed neutrino production via inflation

Duarte Feiteira, Fotis Koutroulis, Oleg Lebedev +1

Inflationary expansion of space-time provides us with an efficient particle production mechanism in the Early Universe. The fermion production efficiency depends critically on the…

hep-ph2025

Cosmological gravitational particle production: Starobinsky vs Bogolyubov, uncertainties, and issues

Duarte Feiteira, Oleg Lebedev

We study production of free and feebly interacting scalars during inflation using the Bogolyubov coefficient and Starobinsky stochastic approaches. While the two methods agree in t…

gr-qc2024

Penrose and super-Penrose energy extraction from a Reissner-Nordström black hole spacetime with a cosmological constant through the BSW mechanism: Full story

Duarte Feiteira, José P. S. Lemos, Oleg B. Zaslavskii

The Penrose process, a process that transfers energy from a black hole to infinity, together with the BSW mechanism, which uses collisions of ingoing particles at the event horizon…