Laura Iacconi

Closing in on α -attractors

Laura Iacconi, Sukannya Bhattacharya, Matteo Fasiello, David Wands

Abstract Recent observations of cosmic microwave background (CMB) anisotropies combined with large-scale structure may point towards higher values of the scalar spectral index, n s . This puts previously preferred inflationary models, such as α -attractors, in tension with the new measurements. …

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Closing in on $α$-attractors

Laura Iacconi, Sukannya Bhattacharya, Matteo Fasiello, David Wands

Recent observations of cosmic microwave background (CMB) anisotropies combined with large-scale structure may point towards higher values of the scalar spectral index, $n_s$. This puts previously preferred inflationary models, such as $α$-attractors, in tension with the new measurements. Pending a resolution of …

Primordial correlators from multi-point propagators

Andrea Costantini, Laura Iacconi, David J. Mulryne

Abstract A key step in the comparison between inflationary predictions and cosmological observations is the computation of primordial correlators. Numerical methods have been developed that overcome some of the difficulties arising in analytical calculations when the models considered are complex. The PyTransport …

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Testing inflation on all scales: a case study with α-attractors

Laura Iacconi, Michael Bacchi, Luiz Filipe Guimarães, F. T. Falciano

Abstract A plethora of inflationary models have been shown to produce interesting small-scale phenomenology, such as enhanced scalar fluctuations leading to primordial black hole (PBH) production and large scalar-induced gravitational waves (GW). Nevertheless, good models must simultaneously explain current observations on all …

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Primordial correlators from multi-point propagators

Andrea Costantini, Laura Iacconi, David J. Mulryne

A key step in the comparison between inflationary predictions and cosmological observations is the computation of primordial correlators. Numerical methods have been developed that overcome some of the difficulties arising in analytical calculations when the models considered are complex. The PyTransport package, …

Testing inflation on all scales: a case study with $α$-attractors

Laura Iacconi, Michael Bacchi, Luiz Filipe Guimarães, F. T. Falciano

A plethora of inflationary models can produce interesting small-scale phenomenology, such as enhanced scalar fluctuations leading to primordial black hole (PBH) production and large scalar-induced GW. Nevertheless, good models must simultaneously explain current observations on all scales. In this work, we showcase …

Loop corrections in the separate universe picture

Laura Iacconi, David J. Mulryne, David Seery

Abstract In inflationary models that produce a spike of power on short scales, back-reaction of small-scale substructure onto large-scale modes is enhanced. Loop corrections that quantify this back-reaction have been evaluated by a number of authors. We argue that the separate universe …

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Numerical 1-loop correction from a potential yielding ultra-slow-roll dynamics

Matthew Davies, Laura Iacconi, David J. Mulryne

Abstract Single-field models of inflation might lead to amplified scalar fluctuations on small scales due, for example, to a transient ultra-slow-roll phase. It was argued by Kristiano & Yokoyama in ref. [1] that the enhanced amplitude of the scalar power spectrum on …

gb (code pays fourni par la source)

Loop corrections in the separate universe picture

Laura Iacconi, David J. Mulryne, David Seery

In inflationary models that produce a spike of power on short scales, back-reaction of small-scale substructure onto large-scale modes is enhanced. We argue that the separate universe framework provides a highly convenient tool to compute loop corrections that quantify this back-reaction. Each …

Numerical 1-loop correction from a potential yielding ultra-slow-roll dynamics

Matthew Davies, Laura Iacconi, David J. Mulryne

Single-field models of inflation might lead to amplified scalar fluctuations on small scales due, for example, to a transient ultra-slow-roll phase. It was argued by Kristiano $\&$ Yokoyama in arXiv:2211.03395 that the enhanced amplitude of the scalar power spectrum on small scales …

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Novel CMB constraints on the α parameter in alpha-attractor models

Laura Iacconi, Matteo Fasiello, J. Väliviita, David Wands

Abstract Cosmological α-attractors are a compelling class of inflationary models. They lead to universal predictions for large-scale observables, broadly independent from the functional form of the inflaton potential. In this work we derive improved analytical predictions for the large-scale observables, whose dependence …

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

Laura Iacconi, David J. Mulryne

Abstract 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 …

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