Barenboim, G., Chun, E. J., & Lee, H. M. (2014). Coleman-Weinberg inflation in light of Planck. Phys. Lett. B, 730, 81–88.
Abstract: We revisit a single field inflationary model based on Coleman-Weinberg potentials. We show that in small field Coleman-Weinberg inflation, the observed amplitude of perturbations needs an extremely small quartic coupling of the inflaton, which might be a signature of radiative origin. However, the spectral index obtained in a standard cosmological scenario turns out to be outside the 2 sigma region of the Planck data. When a non-standard cosmological framework is invoked, such as brane-world cosmology in the Randall-Sundrum model, the spectral index can be made consistent with Planck data within la, courtesy of the modification in the evolution of the Hubble parameter in such a scheme. We also show that the required inflaton quartic coupling as well as a phenomenologically viable B – L symmetry breaking together with a natural electroweak symmetry breaking can arise dynamically in a generalized B – L extension of the Standard Model where the full potential is assumed to vanish at a high scale.
|
Lee, H. M., Park, M., & Sanz, V. (2025). Gravity-Mediated Dark Matter at a low reheating temperature. J. High Energy Phys., 05(5), 126–26pp.
Abstract: We present a new study on the Gravity-Mediated Dark Matter (GMDM) scenario, where interactions between dark matter (DM) and the Standard Model are mediated by spin-two particles. Expanding on this established framework, we explore a novel regime characterized by a low reheating temperature that offers an alternative to the conventional thermal relic paradigm. This approach opens new possibilities for understanding the dynamics of the dark sector, encompassing both the dark matter particles (fermion, scalar and vector) and the spin-two mediators. Our analysis examines the constraints imposed by the relic abundance of DM, collider experiments, and direct detection searches, spanning a wide mass range for the dark sector, from very light to extremely heavy states. This work opens new possibilities for the phenomenology of GMDM.
|
