Related papers: Quantum Primordial Standard Clocks
Out-of-equilibrium, non-perturbative, quantum effects significantly modify the standard picture of inflation in a wide class of models including new, natural, and hybrid inflation. We find that the quantum evolution of a single real…
We report on a new class of fast-roll inflationary models. In a huge part of its parameter space, inflationary perturbations exhibit quite unusual phenomena such as scalar and tensor modes freezing out at widely different times, as well as…
A clock is, from an information-theoretic perspective, a system that emits information about time. One may therefore ask whether the theory of information imposes any constraints on the maximum precision of clocks. Here we show a…
Gauge invariant local observables describing primordial scalar quantum fluctuations in Inflationary Cosmology are identified as elements of a type $II$ de Sitter crossed product algebra. This algebra is defined, after adding a reference…
According to the inflationary scenario, all structure in the Universe can be traced back to quantum fluctuations of the metric and scalar field(s) during inflation. The seeds of this structure can be observed as classical anisotropies in…
During inflation explicit perturbative computations of quantum field theories which contain massless, non-conformal fields exhibit secular effects that grow as powers of the logarithm of the inflationary scale factor. Starobinskii's…
Inflation models can have an early phase of inflation where the evolution of the inflaton is driven by quantum fluctuations before entering the phase driven by the slope of the scalar field potential. For a Coleman-Weinberg potential this…
We consider small-field models which invoke the usual framework for the effective field theory, and large-field models which go beyond that. Present and future possibilities for discriminating between the models are assessed, on the…
We propose a model of inflation with a suitable potential for a single scalar field which falls in the wide class of hilltop inflation. We derive the analytical expressions for most of the physical quantities related to inflation and show…
We argue that massive quantum fields source low-frequency long-wavelength metric fluctuations through the quantum fluctuations of their stress-energy, given reasonable assumptions about the analytic structure of its correlators. This can be…
We show that the quantum dynamics of a real scalar field for a large class of potentials in the symmetric Gaussian state, where the nonperturbative quantum contributions are taken into account, can be described equivalently by a…
We review why the search for a causal explanation of the large scale properties of the universe supports the idea that an extended period of accelerated expansion, called inflation, preceded primordial nucleosynthesis. As a consequence of…
The production of a stochastic background of gravitational waves is a fundamental prediction of any cosmological inflationary model. The features of such a signal encode unique information about the physics of the Early Universe and beyond,…
In this paper we study the inflation model driven by the phantom field. We propose a possible exit from phantom inflation to our observational cosmology by introducing an additional normal scalar field, similar to hybrid inflation model.…
We consider the generation of large-scale magnetic fields in slow-roll inflation. The inflaton field is described in a supergravity framework where the conformal invariance of the electromagnetic field is generically and naturally broken.…
We show that the fluctuations of quantum fields as seen by late comoving observers are significantly influenced by the history of the early Universe, and therefore they transmit information about the nature of spacetime in timescales when…
Does the observable spectrum of cosmic fluctuations depend on detailed initial conditions? This addresses the question if the general inflationary paradigm is sufficient to predict within a given model the spectrum and amplitude of cosmic…
In a previous work we have exhibited a clear description of the quantum-to-classical transition of cosmological quantum fluctuations in the inflationary scenario using the de Broglie-Bohm quantum theory. These fluctuations are believed to…
An investigation is undertaken into the properties and effects of a preinflationary era during at least part of which semiclassical gravity was valid. It is argued that if the Universe (or our part of it) was approximately homogeneous and…
Introducing a variable cosmological parameter $\Lambda (t)$ in a geometrical manner from a 5D Riemann-flat metric, we investigate the origin and evolution of primordial magnetic fields in the early universe, when the expansion is governed…