Reheating induced by competing decay modes

In this work one shows that a generalized non-minimal coupling between geometry and matter is compatible with Starobinsky inflation and leads to a successful process of preheating, a reheating scenario based on the production of massive particles via parametric resonance. The model naturally extends the usual preheating mechanism, which resorts to an ad-hoc scalar curvature-dependent mass term for a scalar field χ, and also encompasses a previously studied preheating channel based upon a non-standard kinetic term.

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“…( 53) can be found in Ref. [14]). Furthermore, one sees that the latter compares with the dominant term from the Hubble expansion as…”

Section: Preheatingmentioning

confidence: 93%

“…Furthermore, preheating may also be implemented with more evolved couplings, e.g. a quadratic coupling R 2 χ [13,14] or via a non-standard kinetic term for the matter scalar field, of the form g(R)(∂χ) 2 [15].…”

Section: Introductionmentioning

confidence: 99%

Reheating via a generalized nonminimal coupling of curvature to matter

2011

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“…More evolved couplings also lead to preheating, as found in Refs. (Charters et al 2008;Lachapelle & Brandenberger 2009). This hints that the non-minimally coupled action (1) may generalize the preheating scenario.…”

Section: Post-inflationary Reheatingmentioning

confidence: 74%

Testing a non-minimal coupling between matter and curvature

Páramos

2011

Preprint

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One of the most interesting and current phenomenological extensions of General Relativity is the so-called f (R) class of theories; a natural generalization of this includes an explicit non-minimal coupling between matter and curvature. The purpose of this work is to present a unified view of the applicability of the latter to various contexts, ranging from astrophysical matter distributions to a cosmological setting. Various results are discussed, including the impact of this non-minimal coupling in the choice of Lagrangian density, a mechanism to mimic galactic dark matter and a Cosmological Constant at a astrophysical scale, the possibility of accounting for the accelerated expansion of the Universe and modifications to post-inflationary reheating. The equivalence between a model exhibiting a non-minimal coupling and multi-scalar-theories is also discussed.

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“…In the non-canonical limit, the equation of motion for the reheaton perturbations (30) can be written in a simple and suggestive form by making a redefinition to a different dimensionless time coordinate than we considered earlier:…”

Section: B Non-canonical Limitmentioning

confidence: 99%

“…There exists a straightforward method of computing the Floquet exponent µ k as a function of the parameters A k and q, which has been extensively covered in the literature (e.g. [29][30][31]).…”

Section: Appendix A: Computing the Floquet Exponentmentioning

confidence: 99%

Preheating with the Brakes On: The Effects of a Speed Limit

Karouby,

Underwood,

Vincent

2011

Preprint

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We study preheating in models where the inflaton has a non-canonical kinetic term, containing powers of the usual kinetic energy. The inflaton field oscillating about its potential minimum acts as a driving force for particle production through parametric resonance. Non-canonical kinetic terms can impose a speed limit on the motion of the inflaton, modifying the oscillating inflaton profile. This has two important effects: it turns a smooth sinusoidal profile into a sharp saw-tooth, enhancing resonance, and it lengthens the period of oscillations, suppressing resonance. We show that the second effect dominates over the first, so that preheating with a non-canonical inflaton field is less efficient than with canonical kinetic terms, and that the expansion of the Universe suppresses resonance even further.

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Reheating induced by competing decay modes

Cited by 6 publications

References 43 publications

Reheating via a generalized nonminimal coupling of curvature to matter

Reheating via a generalized nonminimal coupling of curvature to matter

Testing a non-minimal coupling between matter and curvature

Preheating with the Brakes On: The Effects of a Speed Limit

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