Results 11 to 20 of about 375 (91)
Full higher-dimensional analysis of moduli oscillation and radiation in expanding universe
Journal of High Energy Physics, 2023 We investigate effects of the radiation and the moduli oscillation around the stabilized values on the evolution of a 6-dimensional spacetime compactified on S 2.
Hajime Otsuka, Yutaka Sakamura
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Freeze-in dark matter via lepton portal: Hubble tension and stellar cooling
Journal of High Energy Physics, 2023 We propose a new freeze-in dark matter candidate which feebly couples to the standard model charged leptons. The feeble interactions allow it (i) to freeze-in from the Standard Model thermal bath with its relic density being either a fraction or the ...
Zixuan Xu +3 more
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Scalar field couplings to quadratic curvature and decay into gravitons
Journal of High Energy Physics, 2022 Any field, even if it lives in a completely hidden sector, interacts with the visible sector at least via the gravitational interaction. In this paper, we show that a scalar field in such a hidden sector generically couples to the quadratic curvature via
Yohei Ema +2 more
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Black hole evaporation beyond the Standard Model of particle physics
Journal of High Energy Physics, 2023 The observation of an evaporating black hole would provide definitive information on the elementary particles present in nature. In particular, it could discover or exclude particles beyond those present in the standard model of particle physics.
Michael J. Baker, Andrea Thamm
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Tree-level unitarity in Higgs inflation in the metric and the Palatini formulation
Journal of High Energy Physics, 2022 We calculate the tree-level amplitudes for electrically neutral 2 → 2 scattering for the Standard Model Higgs doublet non-minimally coupled to the Ricci scalar. We consider both the metric and the Palatini formulation of gravity. We find the partial wave
Asuka Ito, Wafaa Khater, Syksy Räsänen
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Savior curvatons and large non-Gaussianity
Journal of High Energy Physics, 2023 Curvatons are light (compared to the Hubble scale during inflation) spectator fields during inflation that potentially contribute to adiabatic curvature perturbations post-inflation.
Jackie Lodman, Qianshu Lu, Lisa Randall
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Primordial gravitational waves from excited states
Journal of High Energy Physics, 2022 We show that a scalar excited state with large occupation numbers during inflation leads to an enhancement of tensor modes and a characteristic pattern of order-one oscillations in the associated stochastic gravitational wave background (SGWB) sourced ...
Jacopo Fumagalli +5 more
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Hierarchies from landscape probability gradients and critical boundaries
Journal of High Energy PhysicsIf the gradient of a probability distribution on a landscape of vacua aligns with the variation of some fundamental parameter, the parameter may be likely to take some non-generic value.
Oleksii Matsedonskyi
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Moduli trapping mechanism in modular flavor symmetric models
Journal of High Energy Physics, 2023 We discuss how the moduli in modular flavor symmetric models dynamically select enhanced symmetry points at which the residual modular symmetry renders extra matter fields massless.
Shota Kikuchi +3 more
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Thermal production of astrophobic axions
Journal of High Energy PhysicsHot axions are produced in the early Universe via their interactions with Standard Model particles, contributing to dark radiation commonly parameterized as ∆N eff.
Marcin Badziak +3 more
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