Squeezed bispectrum and one-loop corrections in transient constant-roll inflation

Motohashi, Hayato; Tada, Yuichiro

doi:10.48550/arxiv.2303.16035

Cited by 6 publications

(8 citation statements)

References 106 publications

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“…Moreover, ref. [145] provides a straightforward counterexample to the no-go theorem of PBH production from single-field inflation claimed in [134,135] by considering the transient constant-roll inflation. Note that the situation in our model is somewhat different.…”

Section: Jcap06(2023)012mentioning

confidence: 97%

Primordial black holes and induced gravitational waves from double-pole inflation

Wang

2023

J. Cosmol. Astropart. Phys.

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The primordial black hole (PBH) productions from the inflationary potential with an inflection point usually rely heavily on the fine-tuning of the model parameters. We propose in this work a new kind of the α-attractor inflation with asymmetric double poles that naturally and easily lead to a period of non-attractor inflation, during which the PBH productions are guaranteed with less fine-tuning the model parameters. This double-pole inflation can be tested against the observational data in the future with rich phenomenological signatures: (1) the enhanced curvature perturbations at small scales admit a distinctive feature of ultraviolet oscillations in the power spectrum; (2) the quasi-monochromatic mass function of the produced PBHs can be made compatible to the asteroid-mass PBHs as the dominant dark matter component, the planet-mass PBHs as the OGLE ultrashort-timescale microlensing events, and the solar-mass PBHs as the LIGO-Virgo events; (3) the induced gravitational waves can be detected by the gravitational-wave detectors in space and Pulsar Timing Array/Square Kilometer Array.

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Section: Jcap06(2023)012mentioning

confidence: 97%

Primordial black holes and induced gravitational waves from double-pole inflation

Wang

2023

J. Cosmol. Astropart. Phys.

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“…There are many possible directions for future work. Similarly to what has been done for single-field models leading to enhanced fluctuations [75][76][77][79][80][81][82][83], one could check the viability of multi-field models by calculating the one-loop correction to the tree-level scalar power spectrum. Note that this approach does not rely on the assumption of the non-Gaussianity being of the local type.…”

Section: Discussionmentioning

confidence: 99%

“…This method can be employed for cases where the non-Gaussianity is not of the local type. Loop corrections in single-field models delivering large scalar fluctuations have been calculated recently[75][76][77][78][79][80][81][82][83][84][85][86][87] (for an earlier work see[88]), while to our knowledge this attempt has not been done for multi-field models.…”

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confidence: 99%

Multi-field inflation with large scalar fluctuations: non-Gaussianity and perturbativity

Iacconi,

Mulryne

2023

J. Cosmol. Astropart. Phys.

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Recently multi-field inflation models that can produce large scalar fluctuations on small scales have drawn a lot of attention, primarily because they could lead to primordial black hole production and generation of large second-order gravitational waves. In this work, we focus on models where the scalar fields responsible for inflation live on a hyperbolic field space. In this case, geometrical destabilisation and non-geodesic motion are responsible for the peak in the scalar power spectrum. We present new results for scalar non-Gaussianity and discuss its dependence on the model's parameters. On scales around the peak, we typically find that the non-Gaussianity is large and close to local in form. We validate our results by employing two different numerical techniques, utilising the transport approach, based on full cosmological perturbation theory, and the δN formalism, based on the separate universe approximation. We discuss implications of our results for the perturbativity of the underlying theory, focusing in particular on versions of these models with potentially relevant phenomenology at interferometer scales.

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“…Recently, a series of papers [56][57][58][59] have suggested that a high power spectrum P R ∼ 10 −2 may produce strong loop corrections that ruin the model's cosmic microwave background (CMB) predictions, ruling out inflationary PBHs (see [60][61][62] for a critical take). I have demonstrated that stochastic effects can lower the P R required for PBH production, down to ∼ 10 −3 in an example case of constant-roll inflation.…”

Section: Discussionmentioning

confidence: 99%

A numerical approach to stochastic inflation and primordial black holes

Tomberg

2021

J. Phys.: Conf. Ser.

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Certain models of cosmic inflation produce strong cosmological perturbations at short length scales, which may later collapse into primordial black holes. To find the statistics of these strong perturbations and the ensuing black holes, it is necessary to go beyond linear perturbation theory. Stochastic inflation provides a way to take the leading non-linear effects into account. In this contribution, I discuss recent progress in numerical computations of stochastic inflation. A numerical approach can include more of the non-linearities than an analytical calculation, and can be applied to single-field inflationary models with any potential.

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Squeezed bispectrum and one-loop corrections in transient constant-roll inflation

Cited by 6 publications

References 106 publications

Primordial black holes and induced gravitational waves from double-pole inflation

Primordial black holes and induced gravitational waves from double-pole inflation

Multi-field inflation with large scalar fluctuations: non-Gaussianity and perturbativity

A numerical approach to stochastic inflation and primordial black holes

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