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Related papers: The Decay of the Inflaton in No-scale Supergravity

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We point out that supergravity effects enable the inflaton to decay into all matter fields, including the visible and the supersymmetry breaking sectors, once the inflaton acquires a non-vanishing vacuum expectation value. The new decay…

High Energy Physics - Phenomenology · Physics 2009-11-11 Motoi Endo , Masahiro Kawasaki , Fuminobu Takahashi , T. T. Yanagida

We discuss inflaton decay in supergravity, taking account of the gravitational effects. It is shown that, if the inflaton has a nonzero vacuum expectation value, it generically couples to any matter fields that appear in the superpotential…

High Energy Physics - Phenomenology · Physics 2008-11-26 Motoi Endo , Fuminobu Takahashi , T. T. Yanagida

We have recently shown that, if the inflaton has a nonzero vacuum expectation value, it generically couples to any matter fields that appear in the superpotential at the tree level, and to any gauge sectors through anomalies in the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Fuminobu Takahashi

It is known that gravitinos are non-thermally produced in inflaton decay processes, which excludes many inflation models for a wide range of the gravitino mass. We find that the constraints from the gravitino overproduction can be greatly…

High Energy Physics - Phenomenology · Physics 2015-06-11 Kazunori Nakayama , Fuminobu Takahashi , Tsutomu T. Yanagida

We propose a non-oscillatory no-scale supergravity model of inflation (NO-NO inflation) in which the inflaton does not oscillate at the end of the inflationary era. Instead, the Universe is then dominated by the inflaton kinetic energy…

High Energy Physics - Phenomenology · Physics 2021-03-31 John Ellis , Dimitri V. Nanopoulos , Keith A. Olive , Sarunas Verner

We show that the gravitino-overproduction problem is prevalent among inflation models in supergravity. An inflaton field generically acquires (effective) non-vanishing auxiliary field, if the Kahler potential is non-minimal. The inflaton…

High Energy Physics - Phenomenology · Physics 2008-11-26 Masahiro Kawasaki , Fuminobu Takahashi , T. T. Yanagida

We consider the decay of the inflaton in Starobinsky-like models arising from either an $R+R^2$ theory of gravity or $N=1$ no-scale supergravity models. If Standard Model matter is simply introduced to the $R + R^2$ theory, the inflaton…

High Energy Physics - Phenomenology · Physics 2024-04-24 Yohei Ema , Marcos A. G. Garcia , Wenqi Ke , Keith A. Olive , Sarunas Verner

We revisit Higgs inflation in the framework of a minimal extension of the Standard Model gauge symmetry by a $U(1)_{B-L}$ factor. Various aspects are taken into account with particular focus on the role of the supersymmetry breaking (SUSY)…

High Energy Physics - Phenomenology · Physics 2021-09-29 Waqas Ahmed , Athanasios Karozas , George K. Leontaris

We study reheating processes and its cosmological consequences in the Starobinsky model embedded in the old-minimal supergravity. First, we consider minimal coupling between the gravity and matter sectors in the higher curvature theory, and…

High Energy Physics - Phenomenology · Physics 2015-06-23 Takahiro Terada , Yuki Watanabe , Yusuke Yamada , Jun'ichi Yokoyama

We utilize a recently proposed cubic nilpotent superfield to realize inflation in supergravity with the minimal degrees of freedom: the inflaton, graviton, and massive gravitino. As an advantage, the resultant model is free from the…

High Energy Physics - Theory · Physics 2021-06-30 Takahiro Terada

We consider the potential problems due to the production of inflatinos and gravitinos after inflation. Inflationary models with a single scale set by the microwave background anisotropies have a low enough reheat temperature to avoid…

High Energy Physics - Phenomenology · Physics 2009-09-15 Hans Peter Nilles , Keith A. Olive , Marco Peloso

By using a No-Scale Supergravity model, which was proved to explain WMAP observations appropriately, a mechanism of supersymmetry breaking and a preheating just after the end of inflation are investigated. Non-thermal production rate of…

High Energy Physics - Phenomenology · Physics 2010-01-29 Kenji Takagi , Yuta Koshimizu , Toyokazu Fukuoka , Takao Sakai , Hikoya Kasari , Mitsuo J. Hayashi

The success of primordial nucleosynthesis imposes stringent bounds on the abundance of gravitational relics. This is particularly true for gravitinos, which - for models with gravitationally mediated supersymmetry breaking - are expected to…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hans Peter Nilles , Marco Peloso

By using a No-Scale Supergravity model, which was proved well to explain WMAP observations appropriately, a mechanism of preheating just after the end of inflation is investigated. By using the canonically normalized and diagonalized…

High Energy Physics - Phenomenology · Physics 2010-03-03 Yuta Koshimizu , Toyokazu Fukuoka , Kenji Takagi , Hikoya Kasari , Mitsuo J. Hayashi

We consider an inflationary model in the hidden-sector broken supergravity with an effectively large cutoff. The inflaton decay into right-handed neutrinos naturally causes the observed baryon asymmetry of the universe with a reheating…

High Energy Physics - Phenomenology · Physics 2009-11-11 M. Ibe , K. -I. Izawa , Y. Shinbara , T. T. Yanagida

We point out that the inflaton spontaneously decays into any gauge bosons and gauginos via the super-Weyl, Kahler and sigma-model anomalies in supergravity, once the inflaton acquires a non-vanishing vacuum expectation value. In particular,…

High Energy Physics - Phenomenology · Physics 2008-11-26 Motoi Endo , Fuminobu Takahashi , T. T. Yanagida

We study non-thermal gravitino production in the minimal supergravity inflation. In this minimal model utilizing orthogonal nilpotent superfields, the particle spectrum includes only graviton, gravitino, inflaton, and goldstino. We find…

High Energy Physics - Phenomenology · Physics 2017-02-23 Fuminori Hasegawa , Kyohei Mukaida , Kazunori Nakayama , Takahiro Terada , Yusuke Yamada

We present a realistic supergravity inflation model which is free from the overproduction of potentially dangerous relics in cosmology, namely moduli and gravitinos which can lead to the inconsistencies with the predictions of baryon…

High Energy Physics - Phenomenology · Physics 2009-09-29 Patrick B. Greene , Kenji Kadota , Hitoshi Murayama

Most of the inflation models end up with non-vanishing vacuum expectation values of the inflaton fields \phi in the true vacuum, which induce, in general, nonvanishing auxiliary field G_\phi for the inflaton potential in supergravity. We…

High Energy Physics - Phenomenology · Physics 2010-11-05 Masahiro Kawasaki , Fuminobu Takahashi , T. T. Yanagida

We discuss inflaton decays and reheating in no-scale Starobinsky-like models of inflation, calculating the effective equation-of-state parameter, $w$, during the epoch of inflaton decay, the reheating temperature, $T_{\rm reh}$, and the…

High Energy Physics - Phenomenology · Physics 2015-08-06 John Ellis , Marcos A. G. Garcia , Dimitri V. Nanopoulos , Keith A. Olive
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