We present a model for viable gravitational reheating involving a scalar field directly coupled to the Ricci curvature scalar. Crucial to the model is a period of kination after inflation, which causes the Ricci scalar to change sign thus inducing a tachyonic effective mass m2-H2 for the scalar field. The resulting tachyonic growth of the scalar field provides the energy for reheating, allowing for temperatures high enough for thermal leptogenesis. Additionally, the required period of kination necessarily leads to a blue-tilted primordial gravitational wave spectrum with the potential to be detected by future experiments. We find that for reheating temperatures TRH ≲ 1 GeV, the possibility exists for the Higgs field to play the role of the scalar field.
Ricci reheating / Opferkuch, T.; Schwaller, P.; Stefanek, B. A.. - In: JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS. - ISSN 1475-7516. - 2019:7(2019), pp. 1-26. [10.1088/1475-7516/2019/07/016]
Ricci reheating
Opferkuch, T.;Stefanek, B. A.
2019-01-01
Abstract
We present a model for viable gravitational reheating involving a scalar field directly coupled to the Ricci curvature scalar. Crucial to the model is a period of kination after inflation, which causes the Ricci scalar to change sign thus inducing a tachyonic effective mass m2-H2 for the scalar field. The resulting tachyonic growth of the scalar field provides the energy for reheating, allowing for temperatures high enough for thermal leptogenesis. Additionally, the required period of kination necessarily leads to a blue-tilted primordial gravitational wave spectrum with the potential to be detected by future experiments. We find that for reheating temperatures TRH ≲ 1 GeV, the possibility exists for the Higgs field to play the role of the scalar field.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
