Zobrazeno 1 - 10
of 156
pro vyhledávání: '"Oleg Lebedev"'
Publikováno v:
Journal of High Energy Physics, Vol 2024, Iss 7, Pp 1-19 (2024)
Abstract We study freeze-in production of Higgs portal dark matter (DM) at temperatures far below the dark matter mass. The temperature of the Standard Model (SM) thermal bath may have never been high such that dark matter production via thermal emis
Externí odkaz:
https://doaj.org/article/0500363c647647d6b777ba77b379ebe0
Publikováno v:
Journal of High Energy Physics, Vol 2024, Iss 4, Pp 1-20 (2024)
Abstract We consider gravitational production of singlet fermions such as sterile neutrinos during and after inflation. The production efficiency due to classical gravity is suppressed by the fermion mass. Quantum gravitational effects, on the other
Externí odkaz:
https://doaj.org/article/3766b0574d8a4d569dc097988913f424
Autor:
Oleg Lebedev, Takashi Toma
Publikováno v:
Journal of High Energy Physics, Vol 2023, Iss 5, Pp 1-17 (2023)
Abstract 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 equilibrium with the Standard Model fields. Eventually, the
Externí odkaz:
https://doaj.org/article/1d33910ab5294e8fb87d1ecb1c73d56a
Publikováno v:
Journal of High Energy Physics, Vol 2020, Iss 10, Pp 1-41 (2020)
Abstract Sterile neutrinos are one of the leading dark matter candidates. Their masses may originate from a vacuum expectation value of a scalar field. If the sterile neutrino couplings are very small and their direct coupling to the inflaton is forb
Externí odkaz:
https://doaj.org/article/80d90bda80324db0a32d3469f06b143e
Autor:
Oleg Lebedev, Jong-Hyun Yoon
Publikováno v:
Physics Letters B, Vol 821, Iss , Pp 136614- (2021)
We examine an intriguing possibility that a single field is responsible for both inflation and dark matter, focusing on the minimal set–up where inflation is driven by a scalar coupling to curvature. We study in detail the reheating process in this
Externí odkaz:
https://doaj.org/article/0fb7f9ad83bc4a3a99baa306dcad97c5
Publikováno v:
Journal of High Energy Physics, Vol 2019, Iss 8, Pp 1-26 (2019)
Abstract A stable real scalar provides one of the simplest possibilities to account for dark matter. We consider the regime where its coupling to the Standard Model fields is negligibly small. Due to self-coupling, the scalar field can reach thermal
Externí odkaz:
https://doaj.org/article/4775a5205a1b4c81b3b24ceeaae22887
Publikováno v:
Physics Letters B, Vol 789, Iss , Pp 373-377 (2019)
The quartic and trilinear Higgs field couplings to an additional real scalar are renormalizable, gauge and Lorentz invariant. Thus, on general grounds, one expects such couplings between the Higgs and an inflaton in quantum field theory. We find that
Externí odkaz:
https://doaj.org/article/a9db6d356a0e470598e543fa9c30a5b6
Publikováno v:
Molecules, Vol 27, Iss 3, p 871 (2022)
Nearly two decades ago, Alexei Kitaev proposed a model for spin-1/2 particles with bond-directional interactions on a two-dimensional honeycomb lattice which had the potential to host a quantum spin-liquid ground state. This work initiated numerous i
Externí odkaz:
https://doaj.org/article/bbead3808cc24aa7bca03ec440840b9d
Autor:
Oleg Lebedev, Takashi Toma
Publikováno v:
Physics Letters B, Vol 798, Iss , Pp - (2019)
We study production of scalar dark matter via the freeze-in mechanism in the relativistic regime, focusing on the simplest Higgs portal model. We derive the corresponding relativistic reaction rates based on the Bose–Einstein statistics taking into
Externí odkaz:
https://doaj.org/article/73a985f7d58c4667b235b6369d09ce40
Publikováno v:
Physics Letters B, Vol 769, Iss C, Pp 129-133 (2017)
Many models of Higgs portal Dark Matter (DM) find themselves under pressure from increasingly tight direct detection constraints. In the framework of gauge field DM, we study how such bounds can be relaxed while retaining the thermal WIMP paradigm. W
Externí odkaz:
https://doaj.org/article/b6b78a35787e409886f62e4deeb757fa