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Related papers: Fast-Rolling Relaxion

200 papers

Usually inflation ends either by a slow rolling of the inflaton field, which gradually becomes faster and faster, or by a first-order phase transition. We describe a model where inflation ends in a different way, due to a very rapid rolling…

Astrophysics · Physics 2009-09-29 Andrei Linde

We show that in the simplest theories of spontaneous symmetry breaking one can have a stage of a fast-roll inflation. In this regime the standard slow-roll condition |m^2| << H^2 is violated. Nevertheless, this stage can be rather long if…

High Energy Physics - Theory · Physics 2009-11-07 Andrei Linde

Inflation may occur while rolling into the metastable supersymmetry-breaking vacuum of massive supersymmetric QCD. We explore the range of parameters in which slow-roll inflation and long-lived metastable supersymmetry breaking may be…

High Energy Physics - Theory · Physics 2008-11-26 Nathaniel J. Craig

We present a supersymmetric version of a two-field relaxion model that naturalizes tuned versions of supersymmetry. This arises from a relaxion mechanism that does not depend on QCD dynamics and where the relaxion potential barrier height…

High Energy Physics - Phenomenology · Physics 2022-09-09 Jason L. Evans , Tony Gherghetta , Natsumi Nagata , Zoe Thomas

We present a new mechanism for slow-roll inflation based on higher dimensional supersymmetric gauge theory compactified to four dimensions with twisted (supersymmetry breaking) boundary conditions. These boundary conditions lead to a…

High Energy Physics - Theory · Physics 2011-01-27 Joshua L. Davis , Thomas S. Levi , Mark Van Raamsdonk , Kevin R. L. Whyte

The abundance of the QCD axion is known to be suppressed if the Hubble parameter during inflation, $H_{\rm inf}$, is lower than the QCD scale, and if the inflation lasts sufficiently long. We show that the tight upper bound on the inflation…

High Energy Physics - Phenomenology · Physics 2020-06-24 Hiroki Matsui , Fuminobu Takahashi , Wen Yin

Inflection-point inflation is an interesting possibility to realize a successful slow-roll inflation when inflation is driven by a single scalar field with its initial value below the Planck mass ($\phi_I \lesssim M_{Pl}$). In order for a…

High Energy Physics - Phenomenology · Physics 2017-03-08 Nobuchika Okada , Digesh Raut

We study the slow-roll regime of two field inflation, in which the two fields are also coupled through their kinetic terms. Such Lagrangians are motivated by particle physics and by scalar-tensor theories studied in the Einstein frame. We…

Astrophysics · Physics 2009-11-11 Fabrizio Di Marco , Fabio Finelli

We present the first quantum field theory model of inflation that is renormalizable in the matter sector, with a super-Hubble inflaton mass and sub-Planckian field excursions, which is thus technically natural and consistent with a…

High Energy Physics - Phenomenology · Physics 2021-01-11 Mar Bastero-Gil , Arjun Berera , Rudnei O. Ramos , João G. Rosa

We draw attention to the possibility that inflation (i.e. accelerated expansion) might continue after the end of slow roll, during a period of fast oscillations of the inflaton field \phi . This phenomenon takes place when a mild…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Thibault Damour , Viatcheslav F. Mukhanov

The recent measurement of the Higgs boson mass implies a relatively slow rise of the Standard Model Higgs potential at large scales, and a possible second minimum at even larger scales. Consequently, the Higgs field may develop a large…

High Energy Physics - Phenomenology · Physics 2015-07-23 Alexander Kusenko

We adopt the double field natural inflation model motivated by the non-perturbative effects of supergravity and superstring theory to do the slow roll analysis. We show that when the parameters are suitably chosen, there exist ranges of…

General Relativity and Quantum Cosmology · Physics 2019-04-12 Ping Kwan Man Ellgan

The dynamics of both the preinflationary and the preheating epochs for a model consisting of a Higgs inflaton plus an additional auxiliary field are studied in full General Relativity. The minimally coupled auxiliary field allows for…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-20 Cristian Joana

We study models of inflation where the inflaton corresponds to a flat direction in field space and its mass term is generated by gravity mediated soft supersymmetry breaking at high scale. Assuming the inflaton to have non negligible…

High Energy Physics - Phenomenology · Physics 2007-05-23 Laura Covi

We show that the relaxion generically stops its rolling at a point that breaks CP leading to relaxion-Higgs mixing. This opens the door to a variety of observational probes since the possible relaxion mass spans a broad range from sub-eV to…

High Energy Physics - Phenomenology · Physics 2017-06-19 Thomas Flacke , Claudia Frugiuele , Elina Fuchs , Rick S. Gupta , Gilad Perez

We demonstrate that the strict upper bounds on the energy scale of inflation and on the tensor-to-scalar ratio can be somewhat relaxed if we assume that - after an initial period of slow rolling when scales probed today in CMB experiments…

High Energy Physics - Theory · Physics 2020-05-20 Vahid Kamali , Robert Brandenberger

We study the effects of primordial magnetic fields on the inflationary potential in the context of a warm inflation scenario. The model, based on global supersymmetry with a new-inflation-type potential and a coupling between the inflaton…

High Energy Physics - Phenomenology · Physics 2014-10-08 Gabriella Piccinelli , Angel Sanchez , Alejandro Ayala , Ana Julia Mizher

We highlight a new connection between the Standard Model hierarchy problem and the dark matter sector. The key piece is the relaxion field, which besides scanning the Higgs mass and setting the electroweak scale, also constitutes the…

High Energy Physics - Phenomenology · Physics 2020-09-11 Nayara Fonseca , Enrico Morgante

In this paper we wish to point out the possibility of using a complex scalar field in a constant roll inflationary model, as needed for observational viability. We extend the idea of real field inflaton with constant rate of roll to a…

General Relativity and Quantum Cosmology · Physics 2023-07-04 Ali Mohammadi , Nahid Ahmadi , Mehdi Shokri

The relaxion mechanism is a novel solution to the hierarchy problem. In this first statistical analysis of the relaxion mechanism, we quantify the relative plausibility of a QCD and a non-QCD relaxion model versus the Standard Model with…

High Energy Physics - Phenomenology · Physics 2016-09-15 Andrew Fowlie , Csaba Balazs , Graham White , Luca Marzola , Martti Raidal